Repair of Rabbit Focal Articular Cartilage Defects with Autologous Chondrocytes Embedded in Alginate

To evaluate the ability of autologous chondrocyte transplantation to repair articular cartilage defects, autologous chondrocytes embedded in alginate beads were implanted in focal cartilage defects created in 9 New Zealand white rabbits. After 4 weeks of cartilage damage, the right knee was repaired via autologous chondrocyte-alginate constructs transplantation and the left knee was left untreated (control group). The quality of cartilage tissues of both knees was then compared at 3 months following the procedure, as reflected by the quantitative analysis of glucosaminoglycan (GAG) in the cartilage and histological examination of the tissue in accordance to the Brittberg scoring scale. Macroscopic examination showed better regeneration of the defective area following chondrocyte-alginate transplantation repair compared to the non-treated site. Biochemical analysis revealed significantly higher cellular expression of GAG in the treated knee as compared to the non-treated knee [1.12 ± 0.48 µg GAGs / mg protein vs. 0.81 ± 0.17 µg GAGs / mg protein, respectively;

p

=0.008]. The mean Brittberg scores was significantly higher in the treated knee as compared to control knee [6.00 ± 1.23 vs. 1.89 ± 1.54;

p

=0.007]. This result can be explained by the fact that chondrocytes cultured in alginate gel beads retained their ability to synthesize cartilage-specific molecules. The alginate beads were perfectly biocompatible with chondrocytes and surrounding cartilage tissue. These findings also indicated that chondrocyte-alginate transplantation has shown enhanced repair results compared to the nontreated measures.