An in-Vitro Study on Regeneration of Human Nucleus Pulposus by Using Gelatin/Chondroitin-6-Sulfate/Hyaluronan Tri-Copolymer Scaffold

Tissue engineering approaches for treating degenerative intervertebral discs aim to promote tissue regeneration then retard or even reverse the degenerative process. A gelatin/ chondroitin-6-sulfate/hyaluronan tri- copolymer was developed to serve as a bioactive scaffold that could help human nucleus pulposus (NP) cells to preserve their cell viability/ proliferation and promote matrix synthesis. Each scaffold was seeded with 1 × 106 monolayer-expanded human NP cells and then cultured in vitro. Over a 4-week cultivation period, cell–scaffold hybrids demonstrated active cell viability/proliferation and a progressive increase in net production of glycosaminoglycans. In comparison to monolayer cells, scaffold-cultured cells showed significantly higher mRNA expression in collagen II, aggrecan, Sox9, TGFβ1, and TIMP1. Expression of mRNA was significantly suppressed in collagen I, collagen X, IL1, and Fas- associating death domain protein. Histological studies showed newly synthesized glycosaminoglycans deposits and collagen II in scaffolds. These results indicate that the tri-copolymer scaffold could be considered as a promising bioactive scaffold for regenerating human NP