Genipin Cross-linking of Type II Collagen-chondroitin Sulfate-hyaluronan Scaffold for Articular Cartilage Therapy

Articular cartilage extracellular matrixes are composed of type II collagen, chondroitin sulfate (CS) and hyaluronan (HA). Type II collagen is the major structural protein in hyaline cartilage. Modification of the collagen scaffold which mimics articular cartilage biochemically by glycosaminoglycans (GAGs) hyaluronan (HA) and chondroitin sulfate (CS) may enhance chondrocyte differentiation into more functional forms or promote preservation of the differentiated state of the cells. In the investigation, we prepared, characterized, and evaluated type II collagen scaffold with and without HA and CS. In order to fabricate porous scaffold containing collagen, HA and CS the mixture was freeze dried at –20 °C, -80 °C and -196 °C. The porous scaffold was cross-linked by genipin to enhance mechanical stability. Scanning electron microscope (SEM) observation of the scaffold demonstrated that the scaffold had interconnected pores after cross-linking process with mean diameters of 80~300 µm and porosity of 90-95% depending on freezing temperature. In cytotoxicity test using human articular primary cells, the cross-linked scaffold showed no significant cytotoxicity. The data of GAG and DNA content of cultivated cartilage on scaffolds demonstrated that high molecular mass HA and long chain CS have potential to up-regulate biochemical synthesis rate of chondrocytes.