Composite system of PLCL scaffold and heparin-based hydrogel for regeneration of partial-thickness cartilage defects

Delivering isolated chondrocytes with matrix is a promising approach to promote the cartilage repair. The present study attempted to combine the advantages of porous scaffold and hydrogel in delivering chondrocytes to partial-thickness cartilage defects. An electrospun, gelatin-incorporated PLCL scaffold mechanically similar to natural cartilage was fabricated, and chondrocytes were seeded using an injectable heparin-based hydrogel for efficient cell seeding. The scaffold/hydrogel composite showed more enhanced expression of chondrogenic genes and production of GAGs than those prepared without hydrogel. In addition, significant cartilage formation showing good integration with surrounding, similar to natural cartilage, was observed by scaffold/hydrogel composite system in partial-thickness defects of rabbit knees while no regeneration was observed in control defects. Although no exogenous chondrogenic factors were added, it was evident that the scaffold/hydrogel composite system was highly effective and better than the scaffold alone system without hydrogel for cartilage regeneration both in vitro and in vivo.