Evaluation of Nanofiber-Based Polyglycolic Acid Scaffolds for Improved Chondrocyte Retention and In Vivo Bioengineered Cartilage Regeneration

In conventional studies on the regeneration of auricle-shaped cartilage in autogenous models using large animals, there were problems with the cartilage regeneration induction capacity and long-term retention of geometric shape. In this study, the authors sought to improve on outcome in these regards: a nonwoven fabric of polyglycolic acid was developed through nanotechnology, and the effect of nanofiber diameter on in vitro cell-seeding efficiency and the in vivo response after implantation in an autogenous large-animal model were evaluated. Canine chondrocytes were isolated and seeded onto polyglycolic acid fabric ranging from 0.5 to 20 μm in average diameter. Cell seeding efficiency was highest for mid-range polyglycolic acid fibers (average diameter, 0.8, 3.0, and 7.0 μm). Flat and auricle-shaped scaffolds were constructed using polypropylene structural support, sandwiching a nonwoven polyglycolic acid fabric that contained autogenous chondrocytes together with basic fibroblast growth factor-laden particles and an exterior fibrin sealant. Scaffolds were then implanted autogenously and evaluated at 5 and 20 weeks. Biomechanical strength was optimal for polyglycolic acid fiber diameters of 0.8 to 3.0 μm. Optimal cell maintenance and neocartilage response were seen with polyglycolic acid fiber diameters in the same mid-range for nanofiber constructs. These findings demonstrate the potential for nanoscale modulation of auricle-shaped cartilage regeneration in a large-animal model.