GAG-augmented polysaccharide hydrogel: A novel biocompatible and biodegradable material to support chondrogenesis

The quality of articular cartilage engineered using a cell-polymer construc t depends, in part, on the chemical composition of the biomaterial and whet her that biomaterial can support the chondrocytic phenotype. Acknowledging the supportive influence of tissue-specific matrix molecules on the chondro cytic phenotype, we have combined chondroitin sulfate-A (CSA) and chitosan, a glycosaminoglycan (GAG) analog, to develop a novel biomaterial to suppor t chondrogenesis. Chitosan is a polycationic repeating monosaccharide of be ta-1,4-linked glucosamine monomers with randomly located N-acetyl glucosami ne units. Chitosan may be combined with the polyanionic CSA such that ionic crosslinking results in hydrogel formation. Bovine primary articular chond rocytes, when seeded onto a thin layer of CSA-chitosan, form discrete, foca l adhesions to the material and maintain many characteristics of the differ entiated chondrocytic phenotype, including round morphology, limited mitosi s, collagen type II, and proteoglycan production. Our findings suggest CSA- chitosan may be well suited as a carrier material for the transplant of aut ologous chondrocytes or as a scaffold for the tissue engineering of cartila ge-like tissue. (C) 2000 John Wiley & Sons, Inc.