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Li Y, Yuan K, Deng C, Tang H, Wang J, Dai X, Zhang B, Sun Z, Ren G, Zhang H, Wang G. Biliary stents for active materials and surface modification: Recent advances and future perspectives. Bioact Mater 2024; 42:587-612. [PMID: 39314863 PMCID: PMC11417150 DOI: 10.1016/j.bioactmat.2024.08.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 08/27/2024] [Accepted: 08/27/2024] [Indexed: 09/25/2024] Open
Abstract
Demand for biliary stents has expanded with the increasing incidence of biliary disease. The implantation of plastic or self-expandable metal stents can be an effective treatment for biliary strictures. However, these stents are nondegradable and prone to restenosis. Surgical removal or replacement of the nondegradable stents is necessary in cases of disease resolution or restenosis. To overcome these shortcomings, improvements were made to the materials and surfaces used for the stents. First, this paper reviews the advantages and limitations of nondegradable stents. Second, emphasis is placed on biodegradable polymer and biodegradable metal stents, along with functional coatings. This also encompasses tissue engineering & 3D-printed stents were highlighted. Finally, the future perspectives of biliary stents, including pro-epithelialization coatings, multifunctional coated stents, biodegradable shape memory stents, and 4D bioprinting, were discussed.
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Affiliation(s)
- Yuechuan Li
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, National Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, China
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
| | - Kunshan Yuan
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, National Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, China
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
| | - Chengchen Deng
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, National Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, China
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
| | - Hui Tang
- Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
| | - Jinxuan Wang
- School of Biosciences and Technology, Chengdu Medical College, Chengdu, 610500, China
| | - Xiaozhen Dai
- School of Biosciences and Technology, Chengdu Medical College, Chengdu, 610500, China
| | - Bing Zhang
- Nanjing Key Laboratory for Cardiovascular Information and Health Engineering Medicine (CVIHEM), Drum Tower Hospital, Nanjing University, Nanjing, China
| | - Ziru Sun
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
- College of materials science and engineering, Shandong University of Technology, Zibo, 25500, Shandong, China
| | - Guiying Ren
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
- College of materials science and engineering, Shandong University of Technology, Zibo, 25500, Shandong, China
| | - Haijun Zhang
- Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
- National United Engineering Laboratory for Biomedical Material Modification, Dezhou, 251100, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, National Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, China
- School of Biosciences and Technology, Chengdu Medical College, Chengdu, 610500, China
- Nanjing Key Laboratory for Cardiovascular Information and Health Engineering Medicine (CVIHEM), Drum Tower Hospital, Nanjing University, Nanjing, China
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Ishizawa T, Makino N, Kakizaki Y, Matsuda A, Toyokawa Y, Ooyama S, Tanaka M, Ueno Y. Biosafety of a novel covered self-expandable metal stent coated with poly(2-methoxyethyl acrylate) in vivo. PLoS One 2021; 16:e0257828. [PMID: 34559849 PMCID: PMC8462702 DOI: 10.1371/journal.pone.0257828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 09/12/2021] [Indexed: 12/15/2022] Open
Abstract
Covered self-expandable metal stents (CSEMS) are often used for palliative endoscopic biliary drainage; however, the unobstructed period is limited because of sludge occlusion. The present study aimed to evaluate the biosafety of a novel poly(2-methoxyethyl acrylate)-coated CSEMS (PMEA-CSEMS) for sludge resistance and examine its biosafety in vivo. Using endoscopic retrograde cholangiopancreatography, we placed the PMEA-CSEMS into six normal porcine bile ducts and conventional CSEMS into three normal porcine bile ducts. We performed serological examination and undecalcified histological analysis at 1, 3, and 6 months during follow-up. In the bile ducts with PMEA-CSEMS or conventional CSEMS, we observed no increase in liver enzyme or inflammatory marker levels in the serological investigations and mild fibrosis but no inflammatory response in the histopathological analyses. Thus, we demonstrated the biosafety of PMEA-CSEMS in vivo.
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Affiliation(s)
- Tetsuya Ishizawa
- Faculty of Medicine, Department of Gastroenterology, Yamagata University, Yamagata, Japan
- * E-mail: (TI); (NM)
| | - Naohiko Makino
- Faculty of Medicine, Department of Gastroenterology, Yamagata University, Yamagata, Japan
- * E-mail: (TI); (NM)
| | - Yasuharu Kakizaki
- Faculty of Medicine, Department of Gastroenterology, Yamagata University, Yamagata, Japan
| | - Akiko Matsuda
- Faculty of Medicine, Department of Gastroenterology, Yamagata University, Yamagata, Japan
| | | | - Shun Ooyama
- Piolax Medical Devices, Inc., Kanagawa, Japan
| | - Masaru Tanaka
- Frontier Center for Organic Materials, Yamagata University, Yamagata, Japan
- Soft Materials Chemistry, Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan
| | - Yoshiyuki Ueno
- Faculty of Medicine, Department of Gastroenterology, Yamagata University, Yamagata, Japan
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Shabunin AV, Tavobilov MM, Lebedev SS, Karpov AA. [Mechanisms and prevention of biliary stent occlusion]. Khirurgiia (Mosk) 2020:70-75. [PMID: 32500692 DOI: 10.17116/hirurgia202005170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
One of significant achievements of modern endoscopy is development of retrograde biliary stenting for obstructive jaundice. This method ensured widespread application of endoscopic decompression in the treatment of patients with malignant biliary obstruction as preparation before radical surgery and final palliative care. Endoscopic retrograde transpapillary stenting firmly took its place together with antegrade and percutaneous stenting. There are certain advantages of this technique including minimally invasiveness and favorable quality of life. However, this approach is associated with some drawbacks associated with stent occlusion and difficult correction of this complication. The maximum diameter of the plastic stent (PS) is determined by the width of the working channel of the duodenoscope. In this regard, self-expandable metal stents (SEMS) were developed to increase the diameter of bile drainage channel. SEMS are associated with prolonged function. However, there is another problem. It is a germination of SEMS followed by impossible removal of the stent for its subsequent replacement. A further step in development of endoscopic biliary stents was the use of special SEMS coating to exclude tumor or granulation ingrowth. The problem of biliary stent occlusion remains relevant despite some improvement of stenting results. Mechanisms of occlusion of biliary stents and prevention of these events are discussed in this review.
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Affiliation(s)
- A V Shabunin
- Russian Medical Academy for Continuing Professional Education of the Ministry of Health of Russia, Moscow, Russia.,Botkin Municipal Clinical Hospital of the Moscow Healthcare Department, Moscow, Russia
| | - M M Tavobilov
- Russian Medical Academy for Continuing Professional Education of the Ministry of Health of Russia, Moscow, Russia.,Botkin Municipal Clinical Hospital of the Moscow Healthcare Department, Moscow, Russia
| | - S S Lebedev
- Russian Medical Academy for Continuing Professional Education of the Ministry of Health of Russia, Moscow, Russia.,Botkin Municipal Clinical Hospital of the Moscow Healthcare Department, Moscow, Russia
| | - A A Karpov
- Botkin Municipal Clinical Hospital of the Moscow Healthcare Department, Moscow, Russia
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Influence of Polymer Composition on the Controlled Release of Docetaxel: A Comparison of Non-Degradable Polymer Films for Oesophageal Drug-Eluting Stents. Pharmaceutics 2020; 12:pharmaceutics12050444. [PMID: 32403329 PMCID: PMC7284596 DOI: 10.3390/pharmaceutics12050444] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022] Open
Abstract
Following the huge clinical success of drug-eluting vascular stents, there is a significant interest in the development of drug-eluting stents for other applications, such as the treatment of gastrointestinal (GI) cancers. Central to this process is understanding how particular drugs are released from stent coatings, which to a large extent is controlled by drug-polymer interactions. Therefore, in this study we investigated the release of docetaxel (DTX) from a selection of non-degradable polymer films. DTX-polymer films were prepared at various loadings (1, 5 and 10% w/w) using three commercially available polymers including poly(dimethylsiloxane) (PSi), poly (ethylene-co-vinyl acetate) (PEVA) and Chronosil polyurethane (PU). The formulations were characterised using different techniques such as photoacoustic Fourier-transform infrared (PA-FTIR) spectrophotometry, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The effect of DTX on the mechanical properties of the films, in-vitro release, and degradation tests were also assessed. For all polymers and DTX loadings, the drug was found to disperse homogenously without crystallisation within the polymer matrix. While no specific interactions were observed between DTX and PSi or PEVA, hydrogen-bonding appeared to be present between DTX and PU, which resulted in a concentration-dependent decrease in the Young’s moduli of the films due to disruption of inter-polymeric molecular interactions. In addition, the DTX-PU interactions were found to modulate drug release, providing near-linear release over 30 days, which was accompanied by a significant reduction in degradation products. The results indicate that DTX-loaded PU films are excellent candidates for drug-eluting stents for the treatment of oesophageal cancer.
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Yuan XL, Wei B, Ye LS, Wu CC, Tan QH, Yao MH, Zhang YH, Zeng XH, Li Y, Zhang YY, Hu B. New antireflux plastic stent for patients with distal malignant biliary obstruction. World J Gastroenterol 2019; 25:2373-2382. [PMID: 31148908 PMCID: PMC6529883 DOI: 10.3748/wjg.v25.i19.2373] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 03/28/2019] [Accepted: 04/19/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction (MBO). However, the main problem with stent placement is the relatively short duration of stent patency. Although self-expanding metal stents (SEMSs) have a longer patency period than plastic stents (PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS (ARPS) has been proposed. We developed a new ARPS with a "duckbilled" valve attached to the duodenal end of the stent. AIM To compare the patency of ARPSs with that of traditional PSs (TPSs) in patients with unresectable distal MBO. METHODS We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success, adverse events, and patient survival. RESULTS Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events (P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range (IQR), 170], which was significantly longer than that in the TPS group (median, 130 d; IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups (P = 0.900). CONCLUSION The new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency than a TPS.
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Affiliation(s)
- Xiang-Lei Yuan
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Bin Wei
- Department of Gastroenterology, the First Hospital of Xi’an City, Xi’an 710002, Shaanxi Province, China
| | - Lian-Song Ye
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Chun-Cheng Wu
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Qing-Hua Tan
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ming-Hong Yao
- Department of Epidemiology and Health Statistics, West China School of Public Health, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Yu-Hang Zhang
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xian-Hui Zeng
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Yan Li
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Yu-Yan Zhang
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Bing Hu
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
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Bruno MJ, Maluf-Filho F. Palliation of Malignant Pancreaticobiliary Obstruction. CLINICAL GASTROINTESTINAL ENDOSCOPY 2019:734-747.e4. [DOI: 10.1016/b978-0-323-41509-5.00063-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2025]
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Cattò C, Villa F, Cappitelli F. Recent progress in bio-inspired biofilm-resistant polymeric surfaces. Crit Rev Microbiol 2018; 44:633-652. [DOI: 10.1080/1040841x.2018.1489369] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Cristina Cattò
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, Milano, Italy
| | - Federica Villa
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, Milano, Italy
| | - Francesca Cappitelli
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, Milano, Italy
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Tamayo L, Acuña D, Riveros AL, Kogan MJ, Azócar MI, Páez M, Leal M, Urzúa M, Cerda E. Porous Nanogold/Polyurethane Scaffolds with Improved Antibiofilm, Mechanical, and Thermal Properties and with Reduced Effects on Cell Viability: A Suitable Material for Soft Tissue Applications. ACS APPLIED MATERIALS & INTERFACES 2018; 10:13361-13372. [PMID: 29627980 DOI: 10.1021/acsami.8b02347] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The use of implants carries on a series of problems, among them infections, poor biocompatibility, high levels of cytotoxicity, and significant mechanical differences between implants and host organs that promote stress shielding effects. These problems indicate that the materials used to make implants must meet essential requirements and high standards for implantations to be successful. In this work, we present the synthesis, characterization and evaluation of the antibiofilm, mechanical, and thermal properties, and cytotoxic effect of a nanocomposite-based scaffold on polyurethane (PU) and gold nanoparticles (AuNPs) for soft tissue applications. The effect of the quantity of AuNPs on the antibacterial activity of nanocomposite scaffolds was evaluated against Staphylococcus epidermidis and Klebsiella spp., with a resulting 99.99% inhibition of both bacteria using a small quantity of nanoparticles. Cytotoxicity was evaluated with the T10 1/2 test against fibroblast cells. The results demonstrated that porous nanogold/PU scaffolds have no toxic effects on fibroblast cells to the 5 day exposition. With respect to mechanical properties, stress-strain curves showed that the compressive modulus and yield strength of PU scaffolds were significantly enhanced by AuNPs (by at least 10 times). This is due to changes in the arrangement of hard segments of PU, which increase the stiffness of the polymer. Thermogravimetric analysis showed that the degradation onset temperature rises with an increase in the quantity of AuNPs. These properties and characteristics demonstrate that porous nanogold/PU scaffolds are suitable material for use in soft tissue implants.
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Affiliation(s)
- L Tamayo
- Facultad de Ingeniería, Instituto de Ciencias Químicas Aplicadas, Polymers and Macromolecules Center , Universidad Autónoma de Chile , El Llano Subercaseaux 2801 , San Miguel, Santiago 8910060 , Chile
- Departamento de Química, Facultad de Ciencias , Universidad de Chile , Las Palmeras 3425, Casilla 653 , Santiago 8320000 , Chile
| | - D Acuña
- Departamento de Física , Universidad de Santiago , Av. Ecuador 3493 , Santiago 8320000 , Chile
| | - A L Riveros
- Facultad de Ciencias Químicas y Farmacéuticas, Advanced Center for Chronic Diseases (ACCDiS) , Universidad de Chile , Santos Dumont 964, Casilla 233 , Santiago 8320000 , Chile
| | - M J Kogan
- Facultad de Ciencias Químicas y Farmacéuticas, Advanced Center for Chronic Diseases (ACCDiS) , Universidad de Chile , Santos Dumont 964, Casilla 233 , Santiago 8320000 , Chile
| | - M I Azócar
- Departamento de Química de los Materiales, Facultad de Química y Biología , Universidad de Santiago de Chile , Av. L. B. O'Higgins 3363, Casilla 40, Correo 33 , Santiago 8320000 , Chile
| | - M Páez
- Departamento de Química de los Materiales, Facultad de Química y Biología , Universidad de Santiago de Chile , Av. L. B. O'Higgins 3363, Casilla 40, Correo 33 , Santiago 8320000 , Chile
| | - M Leal
- Departamento de Química, Facultad de Ciencias , Universidad de Chile , Las Palmeras 3425, Casilla 653 , Santiago 8320000 , Chile
| | - M Urzúa
- Departamento de Química, Facultad de Ciencias , Universidad de Chile , Las Palmeras 3425, Casilla 653 , Santiago 8320000 , Chile
| | - E Cerda
- Departamento de Física , Universidad de Santiago , Av. Ecuador 3493 , Santiago 8320000 , Chile
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Surwase S, Balakrishnan H, Acharya SK, Makharia GK, Kumaraswamy G, Prasad BLV. Accelerated in vitro model for occlusion of biliary stents: investigating the role played by dietary fibre. BMJ INNOVATIONS 2018; 4:39-45. [DOI: 10.1136/bmjinnov-2017-000209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
BackgroundTo develop a new accelerated in vitro model that has implications for investigating the mechanism of biliary stent occlusion and help in the development of new materials that can alleviate this problem.MethodsWe employ a combination of reconstituted animal bile, bacteria and cellulose fibres optimised to reproducibly generate accelerated occlusion of stents, and produce occlusions that closely mimic those found in clinical studies.ResultsOur model affords repeatable, highly accelerated occlusion (within 2–3 days, compared with between about a week to 2 months in previous models). Our results highlight the role of dietary fibre in blockage of stents and demonstrate their importance in the onset of occlusion.ConclusionsThis accelerated model may have implications for developing biliary stents with enhanced patency.
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Kwon CI, Kim G, Jeong S, Lee WS, Lee DH, Ko KH, Hong SP, Hahm KB. Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating. Gut Liver 2017; 10:632-41. [PMID: 27021507 PMCID: PMC4933426 DOI: 10.5009/gnl15417] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 09/30/2015] [Accepted: 09/30/2015] [Indexed: 12/14/2022] Open
Abstract
Background/Aims The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS. Methods Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS−HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating. Results In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS−HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination. Conclusions Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS.
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Affiliation(s)
- Chang-Il Kwon
- Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Gwangil Kim
- Department of Pathology, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Seok Jeong
- Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea
| | - Won Seop Lee
- Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea
| | - Don Haeng Lee
- Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea
| | - Kwang Hyun Ko
- Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Sung Pyo Hong
- Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Ki Baik Hahm
- Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea
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Choe JW, Hyun JJ. Is There Room for Improvement in Increasing the Stent Patency of Biliary Plastic Stents? Gut Liver 2017; 10:499-501. [PMID: 27377739 PMCID: PMC4933407 DOI: 10.5009/gnl16251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Jung Wan Choe
- Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea
| | - Jong Jin Hyun
- Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea
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12
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The Stent Patency and Migration Rate of Different Shaped Plastic Stents in Bile Flow Phantom Model and In Vivo Animal Bile Duct Dilation Model. Dig Dis Sci 2017; 62:1246-1255. [PMID: 28281171 DOI: 10.1007/s10620-017-4514-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/25/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIM In research and development of biliary plastic stents (PS), continuous efforts have been made to overcome short patency time and high rate of migration. The aim of this study was to evaluate the patency and migration rate of different PS shapes for a given period of time. METHODS Using an in vitro bile phantom model, we compared the patency among different shapes of PS (three straight PS, four double-pigtail PS, and a new screw-shaped PS). We performed an analysis of the degree of luminal narrowing by light microscopic examination. Using an in vivo swine model, we compared the patency and migration rate among the three different types of PS. RESULTS Eight weeks after the bile exposure in the bile flow phantom model, 80 PS were retrieved and analyzed. The straight PS showed less biofilm formation and luminal narrowing than other types of PS (p < 0.05). Forty-nine PS were inserted into the dilated bile ducts of 10 swine models, and 39 PS were successfully retrieved 8 weeks later. The stent migration occurred less frequently in the double-pigtail PS and the screw-shaped PS than it did in the straight PS (11.1, 10, and 27.3%, respectively). However, there was no statistical difference in stent patency among the different shapes. CONCLUSIONS Stent patency may not be significantly different depending on the shape of PS for 8 weeks. The screw-shaped PS showed similar patency and migration rate to the double-pigtail PS. These results may help guiding future PS development and clinical decisions.
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Abstract
The commercial and biobased polyurethane foams (PUF) were produced and characterized in this study. Commercial polyether polyol, crude glycerol, methanol-free crude glycerol, and pure glycerol were used as polyols. Crude glycerol is byproduct of the biodiesel production, and it is a kind of biofuel residue. Polyol blends were prepared by mixing the glycerol types and the commercial polyol with different amounts, 10 wt%, 30 wt%, 50 wt%, and 80 wt%. All types of polyol blends were reacted with polymeric diphenyl methane diisocyanates (PMDI) for the production of rigid foams. Thermal properties of polyurethane foams are examined by thermogravimetric analysis (TGA) and thermal conductivity tests. The structures of polyurethane foams were examined by Fourier Transformed Infrared Spectroscopy (FTIR). Changes in morphology of foams were investigated by Scanning Electron Microscopy (SEM). Mechanical properties of polyurethane foams were determined by compression tests. This study identifies the critical aspects of polyurethane foam formation by the use of various polyols and furthermore offers new uses of crude glycerol and methanol-free crude glycerol which are byproducts of biodiesel industry.
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A comparative study between melt granulation/compression and hot melt extrusion/injection molding for the manufacturing of oral sustained release thermoplastic polyurethane matrices. Int J Pharm 2016; 513:602-611. [DOI: 10.1016/j.ijpharm.2016.09.072] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/23/2016] [Accepted: 09/24/2016] [Indexed: 02/01/2023]
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16
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Time Sequence Evaluation of Biliary Stent Occlusion by Dissection Analysis of Retrieved Stents. Dig Dis Sci 2016; 61:2426-2435. [PMID: 27154511 DOI: 10.1007/s10620-016-4135-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 03/15/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIMS Multiple factors can affect the occlusion of plastic stents. Previous data demonstrate that side holes may induce more biofilm formation probably via microturbulence and bile flow disturbances that could lead to occlusion. These results, however, have not been replicated in subsequent clinical studies with different methods. The objective of this study is to evaluate the physical characteristics of plastic stent occlusion over time. METHODS This is a plastic stent sequential analysis study. Biliary stents removed via ERCP from February 24, 2015, to June 2, 2015, were included. One hundred and forty-eight retrieved straight-type plastic stents were longitudinally cut by a custom-made cutting device. These dissected stents were then evaluated in detail with regard to the location of stent occlusion and the stent patency period. Location of stent occlusive debris was the primary outcome in this study. RESULTS Biofilm formations and occlusions by debris were sequentially but separately tallied. Biofilm formations were initially seen around the side hole areas within 30 days and spread to the entire stent by 60 days. Then, occlusion process by debris was mainly initiated by 80 days and progressed to full occlusion by median of 90 days. Although some occlusions were also observed around the side hole areas within 30 days, affected areas were more widely observed after biofilm formation. CONCLUSIONS This study is the first to attempt to describe the distribution of stent occlusions over time. These observations may help guide future stent development.
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Cauda V, Chiodoni A, Laurenti M, Canavese G, Tommasi T. Ureteral double-J stents performances toward encrustation after long-term indwelling in a dynamic in vitro model. J Biomed Mater Res B Appl Biomater 2016; 105:2244-2253. [PMID: 27459232 DOI: 10.1002/jbm.b.33756] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/14/2016] [Accepted: 07/05/2016] [Indexed: 11/08/2022]
Abstract
Three different single-lumen double-J ureteral stents of different materials were studied and compared after the insertion into a dynamic in vitro model with sterile artificial urine up to 6 months. The aim was to evaluate, at selected time steps of 1, 3, and 6 months, the material performances of the stents in preventing the formation of inorganic encrustations. Morphological, compositional, and qualitative analyses were carried out both before stent insertion and after stent permanence for the different time steps, showing an increasing level of encrustation which remains particularly low in the case of two polyurethane stents. Mechanical tests show that both the polyurethane stents and the chitosan one do not decrease the tensile strength after 6 months of indwelling. Evaluation of the wetting behavior of the stent outer surfaces indicates a hydrophilic behavior in most of the cases, which is generally preserved after immersion in artificial urine for the different time steps. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2244-2253, 2017.
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Affiliation(s)
- Valentina Cauda
- Center for Sustainable Futures, Istituto Italiano di Tecnologia, 10129, Turin, Italy.,Department of Applied Science and Technology, Politecnico di Torino, 10129, Turin, Italy
| | - Angelica Chiodoni
- Center for Sustainable Futures, Istituto Italiano di Tecnologia, 10129, Turin, Italy
| | - Marco Laurenti
- Department of Applied Science and Technology, Politecnico di Torino, 10129, Turin, Italy
| | - Giancarlo Canavese
- Department of Applied Science and Technology, Politecnico di Torino, 10129, Turin, Italy
| | - Tonia Tommasi
- Center for Sustainable Futures, Istituto Italiano di Tecnologia, 10129, Turin, Italy
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Hydrophilic thermoplastic polyurethanes for the manufacturing of highly dosed oral sustained release matrices via hot melt extrusion and injection molding. Int J Pharm 2016; 506:214-21. [DOI: 10.1016/j.ijpharm.2016.04.057] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 11/15/2022]
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Kwon CI, Lehman GA. Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention. Clin Endosc 2016; 49:139-46. [PMID: 27000422 PMCID: PMC4821514 DOI: 10.5946/ce.2016.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 12/17/2022] Open
Abstract
Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations.
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Affiliation(s)
- Chang-Il Kwon
- Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Glen A Lehman
- Division of Gastroenterology and Hepatology, Indiana University School of Medicine, Indianapolis, IN, USA
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Thermoplastic polyurethanes for the manufacturing of highly dosed oral sustained release matrices via hot melt extrusion and injection molding. Eur J Pharm Biopharm 2015; 90:44-52. [DOI: 10.1016/j.ejpb.2014.11.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/04/2014] [Accepted: 11/07/2014] [Indexed: 11/24/2022]
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Vuotto C, Donelli G. Anaerobes in Biofilm-Based Healthcare-Associated Infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 830:97-112. [DOI: 10.1007/978-3-319-11038-7_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Claeys B, De Bruyn S, Hansen L, De Beer T, Remon JP, Vervaet C. Release characteristics of polyurethane tablets containing dicarboxylic acids as release modifiers - a case study with diprophylline. Int J Pharm 2014; 477:244-50. [PMID: 25445517 DOI: 10.1016/j.ijpharm.2014.10.046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/16/2014] [Accepted: 10/18/2014] [Indexed: 11/19/2022]
Abstract
The influence of several dicarboxylic acids on the release characteristics of polyurethane tablets with a high drug load was investigated. Mixtures of diprophylline (Dyph) and thermoplastic polyurethane (TPUR) (ratio: 50/50, 65/35 and 75/25 wt.%) were hot-melt extruded and injection molded with the addition of 1, 2.5, 5 and 10% wt.% dicarboxylic acid as release modifier. Incorporating malonic, succinic, maleic and glutaric acid in the TPUR matrices enhanced drug release, proportional to the dicarboxylic acid concentration in the formulation. No correlation was found between the water solubility, melting point, logP and pKa of the acids and their drug release modifying capacity. Succinic and maleic acid had the highest drug release modifying capacity which was linked to more intense molecular interactions with Dyph. A structural fit between the primary and secondary alcohol of Dyph and both carboxylic groups of the acids was at the origin of this enhanced interaction.
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Affiliation(s)
- Bart Claeys
- Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Sander De Bruyn
- Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Laurent Hansen
- Laboratory of Pharmaceutical Process Analytical Technology, Department of Pharmaceutical Analysis, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Thomas De Beer
- Laboratory of Pharmaceutical Process Analytical Technology, Department of Pharmaceutical Analysis, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Jean Paul Remon
- Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Chris Vervaet
- Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
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Park YJ, Kang DH. Endoscopic drainage in patients with inoperable hilar cholangiocarcinoma. Korean J Intern Med 2013; 28:8-18. [PMID: 23345990 PMCID: PMC3543964 DOI: 10.3904/kjim.2013.28.1.8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 08/06/2012] [Indexed: 02/08/2023] Open
Abstract
Hilar cholangiocarcinoma has an extremely poor prognosis and is usually diagnosed at an advanced stage. Palliative management plays an important role in the treatment of patients with inoperable hilar cholangiocarcinoma. Surgical, percutaneous, and endoscopic biliary drainage are three modalities available to resolve obstructive jaundice. Plastic stents were widely used in the past; however, self-expanding metal stents (SEMS) have become popular recently due to their long patency and reduced risk of side branch obstruction, and SEMS are now the accepted treatment of choice for hilar cholangiocarcinoma. Bilateral drainage provides more normal and physiological biliary flow through the biliary ductal system than that of unilateral drainage. Unilateral drainage was preferred until recently because of its technical simplicity. But, with advancements in technology, bilateral drainage now achieves a high success rate and is the preferred treatment modality in many centers. However, the choice of unilateral or bilateral drainage is still controversial, and more studies are needed. This review focuses on the endoscopic method and discusses stent materials and types of procedures for patients with a hilar cholangiocarcinoma.
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Affiliation(s)
- Ye Jin Park
- Department of Internal Medicine, Pusan National University School of Medicine, Yangsan, Korea
| | - Dae Hwan Kang
- Department of Internal Medicine, Pusan National University School of Medicine, Yangsan, Korea
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Farnbacher MJ, Kraupa W, Schneider HT. Cleaning of occluded biliary endoprostheses: Is shockwave application an alternative to regular stent exchange? J Med Eng Technol 2012; 37:10-6. [DOI: 10.3109/03091902.2012.728673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Farnbacher MJ, Lederer R, Blana A, Schneider HT. Does heparin coating reduce encrustation of biliary plastic endoprostheses? A prospective randomized trial. Scand J Gastroenterol 2012; 47:1141-7. [PMID: 22861490 DOI: 10.3109/00365521.2012.711849] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Common bile duct stenting is widely performed for bridging benign and malignant obstructions. A major limitation is early stent occlusion making regular stent exchange necessary. Covalent binding of glycosaminoglycanes to polyethylene stents proved to reduce encrustation in urological implants. Since development of urological and biliary stent occlusion shows parallels, the aim of the study was to evaluate the efficacy of heparin coating of biliary endoprostheses in preventing encrustation. MATERIAL AND METHODS In a prospective randomized trial, heparin-coated and native stents were endoscopically placed for almost 90 days on average. After removal, all stents were dried (50°C, 24 h), weighed and after longitudinal incision visible encrustation and discoloration recorded. Fifty-three patients (21 females/32 males, 70 ± 12 (42-87) years) were included; 13 patients (4 females/9 males, 58-79 years) completed the study according to the protocol. RESULTS After removal, mean weight of encrustation in native stents was more than double as high as of covered stents (native: 37.9 ± 19.8 (16-93) mg; covered: 17.6 ± 6.7 (9-33) mg). In 12 of 13 cases, the encrustation weight of the native stent was higher than that of the corresponding covered stent in the same patient. Premature stent explantation became necessary in 3 of 13 native stents, because of recurrent jaundice or cholangitis but only in 1 of 13 covered stents. After longitudinal incision, the three uncovered stents showed excessive encrustation whereas no significant encrustation was found in the covered prosthesis. Altogether, covered stents showed less visible accumulation of clogging material and discoloration than native stents. CONCLUSIONS Covalent bound heparin is highly effective in preventing encrustation of biliary polyethylene endoprostheses.
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Affiliation(s)
- Michael J Farnbacher
- Department of Medicine 2, Teaching Hospital Klinikum Fuerth, Friedrich-Alexander University Erlangen-Nuremberg, Jakob-Henle-Strasse 1, Fuerth, Germany.
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Optimizing biliary stent patency by coating with hydrophobin alone or hydrophobin and antibiotics or heparin: an in vitro proof of principle study. Adv Med Sci 2012; 56:138-44. [PMID: 21940267 DOI: 10.2478/v10039-011-0026-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE Although a wide range of biliary plastic and metal stents is on offer nowadays, the ideal cost-effective stent that functions permanently and that is easy to handle regarding its exchange is still not available. Therefore we tested in an in vitro model if the coating of plastic stents with hydrophobin alone or with hydrophobin and antibiotics or heparin in combination leads to an inhibition of the clogging process. METHODS We coated commercially available biliary plastic stents with hydrophobin alone, as well as with hydrophobin and antibiotics or heparin in combination. After an incubation period of 28 days in human bile, we examined the stents by scanning electron microscopy to see whether the clogging material on its surface was reduced. RESULTS Coating of plastic stents with hydrophobin led to a reduction in the amount of adherent material on the surface of the stents. Coupling of ampicillin/sulbactam or levofloxacin did not lead to a further reduction of the clogging material, whereas coupling with highly concentrated heparin did reduce the adherent material. CONCLUSIONS The coating of biliary plastic stents with hydrophobin or with hydrophobin and heparin in combination seems to be a promising option to delay the clogging process.
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Khandwekar AP, Doble M. Physicochemical characterisation and biological evaluation of polyvinylpyrrolidone-iodine engineered polyurethane (Tecoflex(®)). JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:1231-1246. [PMID: 21437640 DOI: 10.1007/s10856-011-4285-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 03/08/2011] [Indexed: 05/30/2023]
Abstract
Bacterial adhesion and encrustation are the known causes for obstruction or blockage of urethral catheters and ureteral stents, which often hinders their effective use within the urinary tract. In this in vitro study, polyvinylpyrrolidone-iodine (PVP-I) complex modified polyurethane (Tecoflex(®)) systems were created by physically entrapping the modifying species during the reversible swelling of the polymer surface region. The presence of the PVP-I molecules on this surfaces were verified by ATR-FTIR, AFM and SEM-EDAX analysis, while wettability of the films was investigated by water contact angle measurements. The modified surfaces were investigated for its suitability as a urinary tract biomaterial by comparing its lubricity and ability to resist bacterial adherence and encrustation with that of base polyurethane. The PVP-I modified polyurethane showed a nanopatterned surface topography and was highly hydrophilic and more lubricious than control polyurethane. Adherence of both the gram positive Staphylococcus aureus (by 86%; **P < 0.01) and gram-negative Pseudomonas aeruginosa (by 80%; *P < 0.05) was significantly reduced on the modified surfaces. The deposition of struvite and hydroxyapatite the major components of urinary tract encrustations were significantly less on PVP-I modified polyurethane as compared to base polyurethane, especially reduction in hydroxyapatite encrustation was particularly marked. These results demonstrated that the PVP-I entrapment process can be applied on polyurethane in order to reduce/lower complications associated with bacterial adhesion and deposition of encrustation on polyurethanes.
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Affiliation(s)
- Anand P Khandwekar
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, 600036, India
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Ferreira LEVVDC, Baron TH. Endoscopic stenting for palliation of malignant biliary obstruction. Expert Rev Med Devices 2011; 7:681-91. [PMID: 20822390 DOI: 10.1586/erd.10.36] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Malignant biliary obstruction results in jaundice, often with symptoms that decrease the quality of life. Biliary stent placement has largely supplanted surgical bypass for palliation of malignant biliary obstruction. Traditional rigid plastic stents are commonly used, inexpensive and easily removed, although with limited duration of stent patency. Self-expandable metal stents (SEMS) attain larger luminal diameters and provide longer patency than traditional rigid plastic stents in patients with distal bile duct obstruction. SEMS are composed of a variety of metals and can be uncoated, partially covered, or fully covered. Data do not support a prolongation of patency with covered SEMS for distal obstruction, although they have the potential for removability. The data to support SEMS for palliation of hilar biliary obstruction are not as convincing and reintervention for stent occlusion can be difficult. In this article, the design and performance of expandable metal stents for treatment of malignant biliary obstruction will be reviewed.
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Andersen TE, Kingshott P, Palarasah Y, Benter M, Alei M, Kolmos HJ. A flow chamber assay for quantitative evaluation of bacterial surface colonization used to investigate the influence of temperature and surface hydrophilicity on the biofilm forming capacity of uropathogenic Escherichia coli. J Microbiol Methods 2010; 81:135-40. [PMID: 20188127 DOI: 10.1016/j.mimet.2010.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/17/2010] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
Abstract
We have established a simple flow chamber-based procedure which provides an accurate and reproducible way to measure the amount of biofilm formed on an implantable biomaterial surface. The method enables the side-by-side evaluation of different materials under hydrodynamic flow conditions similar to those found on an implanted device. We have used the method to evaluate the biofilm forming capacity of clinically isolated Escherichia coli on silicone rubber and on silicone rubber containing a hydrophilic coating. It was found that the surface chemistry influenced the colonization of the isolates very differently. In addition, the temperature was found to have a considerable influence upon the adhesion and biofilm forming capacity of some of the isolates, and that the influence of surface chemistry depended on temperature. Our results suggest that the step from using E. coli laboratory strains to clinical isolates entails a significant rise in complexity and yields results that cannot be generalized. The results should be valuable information for researchers working with pre-clinical evaluation of device-associated E. coli infections.
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Affiliation(s)
- Thomas Emil Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark, 5000 Odense C, Denmark; Nanon A/S, 2605 Brøndby, Denmark.
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Abstract
Peri-ampullary and hepatic malignancies will frequently present with obstructive jaundice. For unresectable tumors, effective and lasting decompression of the biliary tree is essential to improve quality of life and survival. An overview of present treatment modalities for palliation of obstructive jaundice is provided, including a systematic review of the English literature regarding the optimum choice of palliation.
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John T, Rajpurkar A, Smith G, Fairfax M, Triest J. Antibiotic pretreatment of hydrogel ureteral stent. J Endourol 2008; 21:1211-6. [PMID: 17949328 DOI: 10.1089/end.2007.9904] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To compare bacterial adhesion to hydrogel-coated and uncoated ureteral stents. The antimicrobial activity of coated and uncoated stents treated with commonly used antibiotic solutions also was evaluated. MATERIALS AND METHODS Hydrogel coated and uncoated stent segments were dipped in different antibiotic solutions (ciprofloxacin, gentamicin, and cefazolin). Normal saline was used as the control. The segments were incubated in separate broths of Escherichia coli and Enterococcus faecalis to reach the log phase. They were sonicated to free the bacteria, and colony-forming units were determined after 48 hours. To evaluate antibacterial activity, hydrogel-coated and uncoated stent segments were dipped in the above-mentioned antibiotic solutions. Normal saline was used as the control. Segments were incubated in separate Mueller-Hinton agar plates inoculated with E. coli or Enterococcus faecalis, and the zones of inhibition were determined at 24 hours. The duration of antibacterial activity for each bacterium-antibiotic combination also was studied. RESULTS Hydrogel coating did not significantly reduce bacterial adhesion. Zones of inhibition around stent pieces dipped in antibiotic solutions differed with the organism and the antibiotic. Cefazolin produced a significantly larger zone of inhibition with hydrogel-coated stent, but the duration of antibacterial activity was similar to that of uncoated stent. Hydrophilic coating significantly increased the duration of antibacterial activity of ciprofloxacin and gentamicin. CONCLUSION Hydrogel coating on the surface of ureteral stents does not prevent or reduce bacterial adhesion. However, after antibiotic treatment, stents exhibit antibacterial activity in the local environment at greater intensity and for a longer time, depending on the bacterium-antibiotic combination.
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Affiliation(s)
- Tony John
- Department of Urology, Wayne State University, Detroit, Michigan 48201, USA.
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Yang SH, Lee YSJ, Lin FH, Yang JM, Chen KS. Chitosan/poly(vinyl alcohol) blending hydrogel coating improves the surface characteristics of segmented polyurethane urethral catheters. J Biomed Mater Res B Appl Biomater 2007; 83:304-13. [PMID: 17410571 DOI: 10.1002/jbm.b.30796] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Segmented polyurethane (SPU) is commonly used to manufacture urethral catheters. Surface modifications for SPU catheters are needed to reduce friction and protein adsorption, in order to minimize catheter-related complications, including urethral trauma, encrustation, catheter obstruction, bacterial colonization, and infection. In this study, a four-step surface modification method was developed to create a thin lubricious layer of chitosan/poly(vinyl alcohol) (PVA) hydrogel on the SPU catheter. Modification steps included oxidation of the SPU surface, functionalities modification, carbodiimide reaction and coupling, and hydrogel crosslinking. The success of each modification step was confirmed by Fourier transform infrared spectroscopy. Measurement of the water contact angle revealed that hydrogel coating created a highly hydrophilic surface and atomic force microscope analyses demonstrated that the surface was slippery. Protein absorption of the SPU catheter was significantly reduced by coating hydrogel. Chitosan in the hydrogel could provide antimicrobial activity, and the hydrogel coating SPU samples showed significant antibacterial effects in this study. In summary, the four-step modification method developed in this study provided a simple and effective way to coat the surface of SPU catheters with a chitosan/PVA blending hydrogel that could help to minimize the risk of complications related to the use of urethral catheters.
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Affiliation(s)
- Shu-Hua Yang
- Institute of Biomedical Engineering, College of Engineering and College of Medicine, National Taiwan University, Taipei, Taiwan
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Biliary stent clogging solved by nanotechnology? In vitro study of inorganic-organic sol-gel coatings for teflon stents. Gastroenterology 2007; 133:65-71. [PMID: 17631132 DOI: 10.1053/j.gastro.2007.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Accepted: 03/22/2007] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The major drawback of plastic stents for biliary drainage is the occlusion by sludge. Sludge is accrued because the stent surface allows for the adherence of proteins, glycoproteins, or bacteria and the bile flow is insufficient to clean the surface. In this study, experience from nanotechnology to achieve a clean surface by improved soil-release characteristics is used to optimize biliary stent surface. The aim of this study was to examine sludge accumulation in relation to surface characteristics designed by nanotechnology. METHODS A variety of inorganic-organic sol-gel-coated stents were incubated in sterilized human bile and enzyme-active Escherichia coli for 35 days. Materials were Teflon (DuPont, Wilmington, DE) coated with hydrophobic Clearcoat (NTC, Tholey, Germany), Teflon with sol-gel coating synthesized of organic epoxides of 190 g/mol or 500 g/mol, and propylaminosilane without or with fluorsilanes for increased hydrophobicity. Scanning electron microscopy and semiquantitative analysis, blinded to the type of coating, were used to determine the amount of sludge accumulated on the surface. RESULTS Sludge deposition was reduced on the designed surfaces as compared with uncoated Teflon and Clearcoat. The performance of high molecular (500 g/mol) was superior to that of low molecular (190 g/mol) epoxide ligand. However, increasing hydrophobicity by adding fluoraminosilanes resulted in increased adherence of sludge. Less than a micrometer-thin sol-gel coating is inexpensive because very little coating material is required. This is the first published data comparing systematically modified surfaces of biliary stents using nanotechnology. CONCLUSIONS Optimized soil release by sol-gel nanocoating of plastic stents may prevent biliary plastic stents from clogging.
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Dua KS, Reddy ND, Rao VG, Banerjee R, Medda B, Lang I. Impact of reducing duodenobiliary reflux on biliary stent patency: an in vitro evaluation and a prospective randomized clinical trial that used a biliary stent with an antireflux valve. Gastrointest Endosc 2007; 65:819-28. [PMID: 17383650 DOI: 10.1016/j.gie.2006.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Accepted: 09/05/2006] [Indexed: 12/27/2022]
Abstract
BACKGROUND The mechanisms leading to occlusion of plastic biliary stents (PBS) are not known. OBJECTIVE To evaluate the impact of reducing duodenobiliary reflux on stent patency rate. DESIGN A newly designed antireflux PBS (AR-PBS) was tested in vitro by using ox bile. A prospective randomized trial in human beings was conducted. SETTING Tertiary medical center. PATIENTS Patients with malignant bile-duct strictures were studied. INTERVENTIONS A PBS or an AR-PBS stent was placed by using standard techniques, and the patients were followed at regular intervals. Patients presenting with stent occlusion underwent re-stent placement with either a PBS or a metal stent. MAIN OUTCOME MEASUREMENTS In vitro: resistance to retrograde flow and comparison of the basal and peak antegrade flow pressures between the 2 stents. In vivo: stent patency rates, complications, and the efficacy of the stents in improving the liver test. RESULTS The AR-PBS stent could withstand a retrograde pressure gradient of >320 mm Hg compared with <1 mm Hg for the PBS. Secondary to the siphon effect of the valve, the antegrade flow resistance offered by the AR-PBS was on the negative side for all flow rates compared with PBS (P < .001). The median patency of the AR-PBS in human studies was 145 days (range, 52-252 days) compared with 101 days (range, 41-210 days) for the PBS (P = .002). Both stents were equally effective in improving the liver test, and complication rates were similar in the 2 groups. LIMITATIONS The occluded stents were not examined microscopically. CONCLUSIONS The antireflux biliary stent remains patent for a longer time and hence duodenobiliary reflux may be contributing to stent occlusion.
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Affiliation(s)
- Kulwinder S Dua
- Pancreatico-biliary Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Kahaleh M. Antireflux biliary stents: is it time to go with the flow? Gastrointest Endosc 2007; 65:829-31. [PMID: 17466201 DOI: 10.1016/j.gie.2006.10.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Accepted: 10/16/2006] [Indexed: 02/06/2023]
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Donelli G, Guaglianone E, Di Rosa R, Fiocca F, Basoli A. Plastic biliary stent occlusion: factors involved and possible preventive approaches. Clin Med Res 2007; 5:53-60. [PMID: 17456835 PMCID: PMC1855334 DOI: 10.3121/cmr.2007.683] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Endoscopic biliary stenting is today the most common palliative treatment for patients suffering from obstructive jaundice associated with malignant hepatobiliary tumors or benign strictures. However, recurrent jaundice, with or without cholangitis, is a major complication of a biliary endoprosthesis insertion. Thus, stent removal and replacement with a new one frequently occurs as a consequence of device blockage caused by microbial biofilm growth and biliary sludge accumulation in the lumen. Factors and mechanisms involved in plastic stent clogging arising from epidemiological, clinical and experimental data, as well as the possible strategies to prevent biliary stent failure, will be reviewed and discussed.
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Affiliation(s)
- Gianfranco Donelli
- Department of Technologies and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
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Katsinelos P, Paikos D, Kountouras J, Chatzimavroudis G, Paroutoglou G, Moschos I, Gatopoulou A, Beltsis A, Zavos C, Papaziogas B. Tannenbaum and metal stents in the palliative treatment of malignant distal bile duct obstruction: a comparative study of patency and cost effectiveness. Surg Endosc 2006; 20:1587-93. [PMID: 16897286 DOI: 10.1007/s00464-005-0778-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Accepted: 04/02/2006] [Indexed: 02/08/2023]
Abstract
BACKGROUND Stent clogging is the major limitation of palliative treatment for malignant biliary obstruction. Metal stents have much better patency than plastic stents, but are more expensive. Preliminary data suggest that the recently designed plastic (Tannenbaum) stent has better duration of patency than the polyethylene stent. This study aimed to compare the efficacy and cost effectiveness between the Tannenbaum stent without side holes and the uncovered metal stent for patients with malignant distal common bile duct obstruction. METHODS In this study, 47 patients (median age, 73 years, range, 56-86 years) with inoperable malignant distal common bile duct strictures were prospectively randomized to receive either a Tannenbaum stent (n = 24) or an uncovered self-expandable metal stent (n = 23). The patients were clinically evaluated, and biochemical tests were analyzed if necessary until their death or surgery for gastric outlet obstruction. Cumulative first stent patency and patient survival were compared between the two groups. Cost-effectiveness analysis also was performed for the two study groups. RESULTS The two groups were comparable in terms of age, gender, and diagnosis. The median first stent patency was longer in the metal group than in the Tannenbaum stent group (255 vs 123.5 days; p = 0.002). There was no significant difference in survival between the two groups. The total cost associated with the Tannenbaum stents was lower than for the metal stents (17,700 vs 30,100 euros; p = 0.001), especially for patients with liver metastases (3,000 vs 6,900 euros; p < 0.001). CONCLUSIONS Metal stent placement is an effective treatment for inoperable malignant distal common bile duct obstruction, but Tannenbaum stent placement is a cost-saving strategy, as compared with metal stent placement, especially for patients with liver metastases and expected short survival time.
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Affiliation(s)
- P Katsinelos
- Department of Endoscopy and Motility Unit, Central Hospital, 41 Ethnikis Aminis St., Thessaloniki, 546 35, Greece
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Reddy DN, Banerjee R, Choung OW. Antireflux biliary stents: are they the solution to stent occlusions? Curr Gastroenterol Rep 2006; 8:156-160. [PMID: 16533479 DOI: 10.1007/s11894-006-0012-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Endoscopic insertion of plastic or metal stents is a well-established treatment for malignant biliary obstruction. The major limitation of this technique is stent occlusion. Duodenobiliary reflux has been considered a key contributor to stent occlusion. The presence of plant fibers in 35% to 60% of occluded stents on confocal laser microscopy has further confirmed the presence of reflux when the stent is placed across the papilla. Antireflux stents address this problem by allowing normal antegrade flow but preventing reflux. Recent studies comparing these antireflux stents with the standard Tannenbaum stents have shown significantly prolonged patency. Although initial results are encouraging, larger randomized trials are required to establish efficacy.
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Affiliation(s)
- D Nageshwar Reddy
- Asian Institute of Gastroenterology, 6-3-661, Somajiguda, Hyderabad-500 082, India.
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Hammarström LE. Endobiliary stents for palliation in patients with malignant obstructive jaundice. J Clin Gastroenterol 2005; 39:413-21. [PMID: 15815210 DOI: 10.1097/01.mcg.0000159270.35609.3a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Endobiliary drainage for malignant obstructive jaundice presents a viable palliative alternative. Its role and efficacy depend on factors related to the stent, procedure, and patient. GOALS To review the evidence in the literature in which settings plastic or metal stents are cost-effective, and whether adjuvant measures or patient-related factors affect duration of stent patency. STUDY Using databases a literature search was performed for papers published from 1979 to April 2004. All retrieved papers reporting experimental or clinical observations were rated according to strength of evidence, and carefully analyzed. RESULTS AND CONCLUSIONS Metal stents (Wallstent) stay patent longer than plastic stents (large-bore polyethylene with side-holes), overall median 250 and 110 days, respectively, and seem cost-effective in patients with longer than about 6 months survival, which cannot be accurately predicted. Antibiotics or choleretic agents do not prolong stent patency in clinical settings. In case of stent occlusion, indicated stent exchanges and insertion of a plastic stent, respectively, seem cost-effective in patients initially treated with plastic and metal stents.
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Maeyama R, Kwon IK, Mizunoe Y, Anderson JM, Tanaka M, Matsuda T. Novel bactericidal surface: Catechin-loaded surface-erodible polymer prevents biofilm formation. J Biomed Mater Res A 2005; 75:146-55. [PMID: 16028232 DOI: 10.1002/jbm.a.30346] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We developed a novel bactericidal surface based on a catechin-loaded surface-erodible polymer. (-)-Epigallocatechin-3-gallate (EGCg), which is the main constituent of tea catechins, showed a dose-dependent inhibitory effect on Escherichia coli biofilm formation and a dose-dependent enhanced destructive effect on biofilm. EGCg-immobilized surfaces were prepared by photopolymerization of liquid biodegradable polyesters. The releasing rate was enhanced with an increase in surface-erosion rate of photocured polymers. Polymers with high releasing capacity dose-dependently reduced biofilm formation on the surfaces. The confocal laser scanning microscopic and scanning electron microscopic observations revealed that EGCg induced biofilm-destructing activities, which include bacterial membrane damage, degradation of exopolysaccharides, and detachment of colonized cells. From these results, potential advantages of the clinical use of catechin-loaded polymer-coated implants or catheters are discussed in terms of a reduced occurrence of biomaterial-centered infections without substantial toxicity or adverse effects.
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Affiliation(s)
- Ryo Maeyama
- Division of Biomedical Engineering, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Lin CH, Lin JC, Chen CY, Cheng CY, Lin XZ, Wu JJ. Feasibility evaluation of chitosan coatings on polyethylene tubing for biliary stent applications. J Appl Polym Sci 2005. [DOI: 10.1002/app.21844] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rajpurkar A, Fairfax M, Li H, Dhabuwala CB. Antibiotic Soaked Hydrophilic Coated Bioflex: A New Strategy in the Prevention of Penile Prosthesis Infection. J Sex Med 2004; 1:215-20. [PMID: 16429620 DOI: 10.1111/j.1743-6109.2004.04031.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To find conditions that reduce the susceptibility of penile prostheses to infection, we studied the effect of coating the surface of polyurethane (Bioflex) with a hydrophilic material with and without antibiotics in decreasing bacterial colony counts both in vitro and in experiments in rats. MATERIALS AND METHODS The in vitro experiment was performed using seven strips each of polyvinylpyrrolidone (PVP)-coated and uncoated polyurethane. These strips were dipped in saline for 5 minutes followed by incubation in a suspension of Staphylococcus epidermidis (SE) for a period of 10 minutes. Colony counts were determined after sonication of strips. For the in vitro experiments, 60 rats were used. Thirty animals each had uncoated or coated polyurethane implanted subcutaneously. In each group, strips were implanted after dipping them in either saline (N = 15) or an antibiotic solution (N = 15) consisting of 1 g/L vancomycin and 160 mg/L gentamicin. A bacterial suspension containing SE was then directly introduced into the subcutaneous pockets of all the animals prior to closure. After 7 days, strips were explanted along with 0.5 x 0.5 cm of surrounding tissue, and sonicated. Colony counts were performed on each sonicate. The data were analysed using Student's t-test. A P-value less than or equal to 0.05 was considered to be statistically significant. RESULTS The in vitro study demonstrated a statistically significant (41%) reduction in the colony count of SE within the coated polyurethane strips compared to the uncoated Bioflex strips (150 +/- 44.7 CFU vs. 253 +/- 45.0 CFU, respectively, P-value < 0.05). Animal studies showed that bacterial CFU was highest in the uncoated Bioflex strip (29 +/- 24.5 CFU), followed by uncoated Bioflex with antibiotic treatment (24 +/- 28.1 CFU), coated Bioflex (17 +/- 25.2 CFU) and coated Bioflex with antibiotic treatment (13 +/- 16.1 CFU). Antibiotic treatment of coated Bioflex caused a significant reduction in the bacterial CFU compared to uncoated Bioflex (13 +/- 16.1 vs. 29 +/- 24.5 CFU, respectively, P = 0.04). This represents a 55% reduction in the bacterial count. While the reduction in the bacterial count in the coated Bioflex strip was not statistically different from that in the uncoated strip, a trend towards significance was noted with a 41% reduction (P > 0.05) in bacterial count in the coated Bioflex group compared to uncoated Bioflex. CONCLUSIONS In conclusion, in vitro studies demonstrate a significant (41%) reduction in the colony count of SE in PVP-coated polyurethane compared to uncoated polyurethane. In vivo study in rats showed that antibiotic treatment of PVP-coated Bioflex resulted in a statistically significant reduction (55%) in colony count of SE compared to uncoated Bioflex.
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Affiliation(s)
- Atul Rajpurkar
- Department of Urology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Levy MJ, Baron TH, Gostout CJ, Petersen BT, Farnell MB. Palliation of malignant extrahepatic biliary obstruction with plastic versus expandable metal stents: An evidence-based approach. Clin Gastroenterol Hepatol 2004; 2:273-85. [PMID: 15067620 DOI: 10.1016/s1542-3565(04)00055-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Michael J Levy
- Developmental Endoscopy Unit, Division of Gastroenterology, Mayo Clinic, Rochester, MN 55905, USA.
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Abstract
Endoscopic treatment of pancreatobiliary malignancies has been recognized in the last decades as the treatment of choice in inoperable patients. Endoscopic armamentarium includes biliary stents (plastic and metallic) to bypass neoplastic strictures of the biliary tree, and pancreatic stents to palliate the obstructive pain caused by stenoses of the main pancreatic duct. A major issue is the long-term patency of plastic stents that will eventually clog on average after 3 to 4 months. Self-expandable metallic stents have longer patency, but they can also become occluded by tumor ingrowth or overgrowth; they are also much more expensive; their use is thus recommended in patients with longer life expectancy. Decompression of the dilated main pancreatic duct in pancreatic carcinoma may be effective in the relief of obstructive pain. Endoscopic palliation in pancreatic and biliary malignancies appears safe and effective; management of patient in referral centers, with an available team of gastroenterologists with endoscopic skills, surgeons, and radiologists is recommended.
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Affiliation(s)
- Guido Costamagna
- Digestive Endoscopy Unit, Department Of Surgery, Catholic University of the Sacred Heart, Largo Agostino Gemelli 8, 00168 Rome, Italy.
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Schilling D, Rink G, Arnold JC, Benz C, Adamek HE, Jakobs R, Riemann JF. Prospective, randomized, single-center trial comparing 3 different 10F plastic stents in malignant mid and distal bile duct strictures. Gastrointest Endosc 2003; 58:54-8. [PMID: 12838221 DOI: 10.1067/mge.2003.319] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND The aim of this study was to determine whether patency rates differ with respect to the material, design, and surface texture of 3 different plastic stents. METHODS A total of 120 patients (median age 70.5 years; interquartile range 62-78 years) with malignant mid or distal bile duct strictures, seen between March 1996 and May 1999, were prospectively randomized to receive a 10F polyurethane stent, a Teflon Tannenbaum stent, or a hydrophilic hydromer-coated polyurethane stent. The primary study outcome measure was the interval between stent insertion and the first episode of clogging (or the presence of jaundice at death without stent exchange). All 3 types of stent were studied by scanning electron microscopy before insertion. RESULTS A total of 19 patients were excluded from long-term follow-up. Median duration of stent patency was 76 days overall (interquartile range 29-150 days) and 76 (interquartile range 30-110) days for hydrophilic hydromer-coated polyurethane, 108 (interquartile range 33-186) days for 10F polyurethane, and 58 (interquartile range 21-188) days for Teflon Tannenbaum stents. There were no statistically significant differences among stent types. The hydrophilic hydromer-coated stent had the smoothest surface, as visualized by scanning electron microscopy. CONCLUSIONS No significant differences in the patency of 3 types of stents were detected in this randomized trial. In particular, the hydrophilic hydromer-coated plastic stent did not provide clinical advantages despite its smooth surface.
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Affiliation(s)
- Dieter Schilling
- Department of Internal Medicine C (Gastroenterology and Hepatology), Klinikum der Stadt Ludwigshafen, Academical Teaching Hospital of the University of Mainz, Ludwigshafen/Rhine, Germany
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Hellstrom WJG, Hyun JS, Human L, Sanabria JA, Bivalacqua TJ, Leungwattanakij S. Antimicrobial activity of antibiotic-soaked, Resist-coated Bioflex. Int J Impot Res 2003; 15:18-21. [PMID: 12605236 DOI: 10.1038/sj.ijir.3900941] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study investigates whether a hydrophilic coating (Resist), designed to inhibit bacterial adherence, applied to inflatable penile prostheses can prolong the effect of intraoperative antibiotics. The activity of antibiotic-soaked Bioflex (penile prosthetic substrate material) discs with and without Resist was examined by measuring the zone of inhibition following in vivo exposure in four groups of rabbits: 1, 2, 3 and 5 days' duration of disc implantation. Coated and uncoated discs were soaked in an aqueous solution of gentamicin and bacitracin. The implanted antibiotic-soaked discs were extracted, and the zone of inhibition against four microorganisms in vitro demonstrated that the Resist coating was especially effective against Staphylococcus epidermidis, and statistically significant improvements were observed for the coated over the uncoated substrate up to 3 days following implantation. This effect, and the anti-adherence properties of Resist, may prevent adhesion and colonization of some microorganisms to penile implants and reduce chances for infection.
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Affiliation(s)
- W J G Hellstrom
- Department of Urology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
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Abstract
The associated problems of bacterial biofilm formation and encrustation that may cause obstruction or blockage of urethral catheters and ureteral stents often hinders the effective use of biomaterials within the urinary tract. In this in vitro study, we have investigated the surface properties of a hydrophilic poly(vinyl pyrollidone) (PVP)-coating applied to polyurethane and determined its suitability for use as a urinary tract biomaterial by comparing its lubricity and ability to resist bacterial adherence and encrustation with that of uncoated polyurethane and silicone. The PVP-coated polyurethane was significantly more hydrophilic and more lubricious than either uncoated polyurethane or silicone. Adherence of a hydrophilic Escherichia coli isolate to PVP-coated polyurethane and uncoated polyurethane was similar but significantly less than adherence to silicone. Adherence of a hydrophobic Enterococcus faecalis isolate to PVP-coated polyurethane and silicone was similar but was significantly less than adherence to uncoated polyurethane. Struvite encrustation was similar on the PVP-coated polyurethane and silicone but significantly less than on uncoated polyurethane. Furthermore, hydroxyapatite encrustation was significantly less on the PVP-coated polyurethane than on either uncoated polyurethane or silicone. The results suggest that the PVP-coating could be useful in preventing complications caused by bacterial biofilm formation and the deposition of encrustation on biomaterials implanted in the urinary tract and, therefore, warrants further evaluation.
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Affiliation(s)
- M M Tunney
- School of Pharmacy, Medical Biology Centre, Medical Devices Group, The Queens University of Belfast, UK
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Donelli G, Francolini I, Piozzi A, Di Rosa R, Marconi W. New polymer-antibiotic systems to inhibit bacterial biofilm formation: a suitable approach to prevent central venous catheter-associated infections. J Chemother 2002; 14:501-7. [PMID: 12462430 DOI: 10.1179/joc.2002.14.5.501] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Intravascular catheters are widely employed in medical practice. However, complications such as local or systemic infections are frequently related to their use. The significant increase in this type of nosocomial infection has prompted the search for new strategies to prevent them. This paper reports on an experimental model to prevent catheter-related infections based on the adsorption of a beta-lactam antibiotic (cefamandole nafate) on functionalized urethane polymers. The polyurethanes synthesized were used to coat a commercial central venous catheter. The influence of functional groups on the polymer-antibiotic interaction was analyzed and the kinetics of the antibiotic release from the catheters was dynamically studied. We were able to realize a polymer-antibiotic system able to inhibit bacterial growth up to 7 days. These promising results have encouraged us to extend this experimental model to other polymer-antibiotic systems in order to identify those allowing bacterial growth inhibition for longer times.
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Affiliation(s)
- G Donelli
- Laboratory of Ultrastructure, Istituto Superiore di Sanità, Rome, Italy.
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Zhang H, Tsang TK, Jack CA, Pollack J. Role of bile mucin in bacterial adherence to biliary stents. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2002; 139:28-34. [PMID: 11873242 DOI: 10.1067/mlc.2002.120257] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biliary stent placement is a well-established method of relieving obstructive jaundice. However, a frequent complication is occlusion of the stent caused by bacterial biofilm formation and sludge accumulation. In this study we investigated the possible effect of bile mucin on bacterial adherence to biliary stents at the initial stage of biofilm formation. By means of an in vitro bile-perfusion system, polyethylene stents were perfused with pig gallbladder bile infected with Escherichia coli. The concentrations of mucin in the pig bile were adjusted with purified mucin. The amount of bacteria adhering to the inner surface of the stents was measured and compared for stents perfused with bile containing various concentrations of mucin. Furthermore, we conditioned the stent inner surface with purified pig bile mucin and observed the effect of the conditioning on subsequent bacterial adherence. In addition, a common method for assaying bacterial adhesion with polystyrene microtiter plates was also used in this study. The results demonstrated that more bacteria adhered to the inner surface of stents perfused with bile containing 5 mg/mL mucin than of those perfused with bile containing 0.5 and 0 mg/mL mucin. Increased bacterial adherence was demonstrated on the stent surfaces conditioned with purified mucin compared with that seen on the nonconditioned stent surfaces. The optical densities indicating bacterial adhesion in the microtiter plate wells precoated with mucin were higher than those in non-coated plate wells. The in vitro results indicate that when a biliary stent is implanted in vivo, mucin in bile may condition the stent inner surface, modulate subsequent bacterial adherence to the surface, and participate in stent occlusion.
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Affiliation(s)
- Hongjun Zhang
- Division of Gastroenterology, Department of Medicine, ENH Research Institute, Northwestern University Medical School, Evanston, Illinois, USA
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