Scaffold-free Adipose-derived Stem Cells (ASCs) Improve Experimentally Induced Osteoarthritis in Rabbits

Background: Osteoarthritis (OA) is the most common form of arthritis seen clinically. Current treatments for OA are limited to decreasing associated pain, maintaining or improving joint function, and minimizing disability. However, these treatments have no effect on the regeneration of hyaline cartilage. Since mesenchymal stem cells (MSCs) have been described as promising cell sources for cartilage repair, the present study was designed to examine whether intra-articular injection of scaffold-free adipose-derived stem cells (ASCs) obtained from subcutaneous adipose tissue could restore the matrix of arthritic knee joints in mature animals. Methods: OA was induced in adult white New Zealand rabbits by unilateral anterior cruciate ligament transection (ACLT); the contralateral knee was considered the sham-operated group. At 12 weeks following surgery, the ASCs treated group was injected intra-articularly with a single dose of 1 x 106 cells suspended in 1 mL of medium. The control group received 1 mL of medium without cells and the sham-operated group received no treatment. All rabbits were sacrificed at 16 and 20 weeks after surgery. OA progression was evaluated radiologically, grossly, and histologically using hematoxylin and eosin, Safranin-O, and toluidine blue staining. Results: At 12 weeks after surgery all knees subjected to ACLT showed radiological signs of OA. The findings showed significant differences in the quality of cartilage between ASCs-injected group compared to control group, particularly at 20 weeks after surgery. Conclusion: This study suggests that ASCs obtained from subcutaneous adipose tissue could be a viable approach for treating OA.