Review
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World J Gastrointest Pathophysiol. Feb 15, 2012; 3(1): 19-26
Published online Feb 15, 2012. doi: 10.4291/wjgp.v3.i1.19
Encapsulated islets transplantation: Past, present and future
Naoaki Sakata, Shoichiro Sumi, Gumpei Yoshimatsu, Masafumi Goto, Shinichi Egawa, Michiaki Unno
Naoaki Sakata, Gumpei Yoshimatsu, Shinichi Egawa, Michiaki Unno, Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan
Shoichiro Sumi, Department of Organ Reconstruction, Field of Clinical Application, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606- 8501, Japan
Masafumi Goto, Division of Advanced Surgical Science and Technology, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan
Masafumi Goto, New Industry Creation Hatchery Center, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan
Author contributions: Sakata N designed this review and wrote the first draft; Sumi S, Yoshimatsu G, Goto M and Egawa S revised the draft; Unno M approved the final version to be published; and Egawa S provided the support with his grant.
Supported by Research Seeds Quest Program in Japan Science and Technology Agency (NS); the Uehara Memorial Foundation (NS); and Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports Science and Technology of Japan, B: 22390253 (SE), C: 22591513 (NS)
Correspondence to: Naoaki Sakata, MD, PhD, Assistant Professor of Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan. n-sakata@surg1.med.tohoku.ac.jp
Telephone: +81-22-7177205 Fax: +81-22-7177209
Received: August 17, 2011
Revised: December 4, 2011
Accepted: February 8, 2012
Published online: February 15, 2012
Abstract

Islet transplantation could become an ideal treatment for severe diabetes to prevent hypoglycemia shock and irreversible diabetic complications, once some of the major and unresolved obstacles are overcome, including limited donor supplies and side effects caused by permanent immunosuppressant use. Approximately 30 years ago, some groups succeeded in improving the blood glucose of diabetic animals by transplanting encapsulated islets with semi-permeable membranes consisting of polymer. A semi-permeable membrane protects both the inner islets from mechanical stress and the recipient’s immune system (both cellular and humoral immunities), while allowing bidirectional diffusion of nutrients, oxygen, glucose, hormones and wastes, i.e., immune-isolation. This device, which enables immune-isolation, is called encapsulated islets or bio-artificial pancreas. Encapsulation with a semi-permeable membrane can provide some advantages: (1) this device protects transplanted cells from the recipient’s immunity even if the xenogeneic islets (from large animals such as pig) or insulin-producing cells are derived from cells that have the potential for differentiation (some kinds of stem cells). In other words, the encapsulation technique can resolve the problem of limited donor supplies; and (2) encapsulation can reduce or prevent chronic administration of immunosuppressants and, therefore, important side effects otherwise induced by immunosuppressants. And now, many novel encapsulated islet systems have been developed and are being prepared for testing in a clinical setting.

Keywords: Islet transplantation; Encapsulated islets; Bio-artificial pancreas