• GelMA
• chondral defects
• fluorinated oxadiazoles
• human articular chondrocytes
• hyaline cartilage regeneration
• hypoxia-inducing scaffold
• matrix-assisted autologous chondrocytes implantation (MACI)

• Humans
• Chondrocytes/cytology
• Chondrocytes/metabolism
• Regeneration/drug effects
• Tissue Scaffolds/chemistry
• Cartilage, Articular/physiology
• Cartilage, Articular/cytology
• Tissue Engineering/methods
• Gelatin/chemistry
• Methacrylates/chemistry
• Cell Survival/drug effects
• Cells, Cultured

This study in dogs explored the feasibility of using cartilage fragments removed and discarded during routine palliative surgery for osteochondritis dissecans (OCD) as a source of primary chondrocytes for scaffold-free cartilage tissue-engineering. Primary chondrocytes were obtained from three OCD donors and one age-matched healthy articular cartilage (HAC) donor. After monolayer expansion of primary cells, a three-dimensional spherical suspension culture was implemented. Following this stage, cells were seeded at a high density into custom-made agarose molds that allowed for size and shape-specific constructs to be generated via a method of cellular self-assembling in a scaffold-free environment. Fifty-eight neocartilage constructs were tissue-engineered using this methodology. Neocartilage constructs and native cartilage from shoulder joint were subjected to histological, mechanical, and biochemical testing. OCD and HAC chondrocytes-sourced constructs had uniformly flat morphology and histology consistent with cartilage tissue. Constructs sourced from OCD chondrocytes were 1.5-times (32%) stiffer in compression and 1.3 times (23%) stronger in tension than constructs sourced from HAC chondrocytes and only 8.7-times (81%) less stiff in tension than native tissue. Constructs from both cell sources consistently had lower collagen content than native tissue (22.9%/dry weight [DW] for OCD and 4.1%/DW for HAC vs. 51.1%/DW native tissue). To improve the collagen content and mechanical properties of neocartilage, biological and mechanical stimuli, and thyroid hormone (tri-iodothyronine) were applied to the chondrocytes during the self-assembling stage in two separate studies. A 2.6-fold (62%) increase in compressive stiffness was detected with supplementation of biological stimuli alone and 5-fold (81%) increase with combined biological and mechanical stimuli at 20% strain. Application of thyroid hormone improved collagen content (1.7-times, 33%), tensile strength (1.8-times, 43%), and stiffness (1.3-times, 21%) of constructs, relative to untreated controls. Collectively, these data suggest that OCD chondrocytes can serve as a reliable cell source for cartilage tissue-engineering and that canine chondrocytes respond favorably to biological and mechanical stimuli that have been shown effective in chondrocytes from other animal species, including humans.

• Arthritis
• Bioengineering
• Osteochondrosis
• Scaffold-free tissue-engineering
• Self-assembly
• Thyroid hormone

• Thiolated chitosan; injectable hydrogels
• cartilage tissue engineering
• cell encapsulation
• porous morphology
• transforming growth factor β-1

Radiologists should be familiar with the main techniques of knee cartilage repair and the imaging methods available for its evaluation, in order to optimize the postoperative follow-up of patients. The objective of this study was to present a series of clinical cases seen at our facility, illustrating the main techniques necessary for the repair of knee cartilage, as well as the magnetic resonance imaging techniques used in the postoperative evaluation and the relevant radiological findings.

• Cartilage
• Knee
• Magnetic resonance imaging

• ADSCs
• Adipose
• Biologics
• Formulations
• Regenerative medicine
• Stem cells

We investigated the effect of untransplantable bone marrow-derived mesenchymal stem cells (BMSCs) in acute lung injury (ALI) and whether BMSCs attenuate damage of lipopolysaccharide (LPS) to alveolar type II epithelial cells (AECIIs).

ALI models were prepared by nebulizing LPS and then BMSCs were infused 1 hour later. We observed histopathological changes of lung tissue and evaluated inflammatory exudation by the wet/dry weight ratio, bronchiolar lavage fluid cell count, and protein concentration determination. Inflammatory and vascular factors were detected by immunohistochemistry and western blotting. For in vitro experiments, AECIIs were stimulated with 10 μg/mL LPS for 4 hours and then BMSCs were seeded in transit inserts to co-culture for 24 hours. The activity of AECIIs was detected.

In the LPS + BMSCs group, histopathological examination showed that the degree of lung injury was significantly reduced compared with the LPS group. Protein expression of inflammatory and vascular factors was significantly lower with treatment. Optical density values and cell viability of the LPS + BMSCs group were significantly higher than those of the LPS group.

Untransplanted-BMSCs can inhibit the inflammatory response in ALI and promote repair of AECIIs. This might be due to substances secreted by BMSCs and interaction between these substances.

• Acute lung injury (ALI)
• alveolar type II epithelial cells (AECIIs)
• bone marrow-derived mesenchymal stem cells (BMSCs)
• inflammatory factor
• lipopolysaccharide
• vascular endothelial growth factor

• Mesenchymal stem cells
• articular cartilage defects
• cartilage
• osteoarthritis
• regeneration

Bone is a unique tissue which could regenerate completely after injury rather than heal itself with a scar. Compared with other tissues the difference is that, during bone repairing and regeneration, after the inflammatory phase the mesenchymal stem cells (MSCs) are recruited to the injury site and differentiate into either chondroblasts or osteoblasts precursors, leading to bone repairing and regeneration. Besides these two precursors, the MSCs can also differentiate into adipocyte precursors, skeletal muscle precursors and some other mesodermal cells. With this multilineage potentiality, the MSCs are probably used to cure bone injury and other woundings in the near future. Here we will introduce the recent developments in understanding the mechanism of MSCs action in bone regeneration and repairing.

Knee osteoarthritis is a chronic, indolent disease that will affect an ever increasing number of patients, especially the elderly and the obese. It is characterized by degeneration of the cartilage substance inside the knee which leads to pain, stiffness and tenderness. By some estimations in 2030, only in the United States, this medical condition will burden 67 million people. While conventional treatments like physiotherapy or drugs offer temporary relief of clinical symptoms, restoration of normal cartilage function has been difficult to achieve. Moreover, in severe cases of knee osteoarthritis total knee replacement may be required. Total knee replacements come together with high effort and costs and are not always successful. The aim of this review is to outline the latest advances in stem cell therapy for knee osteoarthritis as well as highlight some of the advantages of stem cell therapy over traditional approaches aimed at restoration of cartilage function in the knee. In addition to the latest advances in the field, challenges associated with stem cell therapy regarding knee cartilage regeneration and chondrogenesis in vitro and in vivo are also outlined and analyzed. Furthermore, based on their critical assessment of the present academic literature the authors of this review share their vision about the future of stem cell applications in the treatment of knee osteoarthritis.

• Multipotent adult mesenchymal stem cells
• Osteoarthritis
• Knee joint
• Clinical trial