Construction of collagen II/hyaluronate/chondroitin-6-sulfate tri-copolymer scaffold for nucleus pulposus tissue engineering and preliminary analysis of its physico-chemical properties and biocompatibility

To construct a novel scaffold for nucleus pulposus (NP) tissue engineering, The porous type II collagen (CII)/hyaluronate (HyA)–chondroitin-6-sulfate (6-CS) scaffold was prepared using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) cross-linking system. The physico-chemical properties and biocompatibility of CII/HyA–CS scaffolds were evaluated. The results suggested CII/HyA–CS scaffolds have a highly porous structure (porosity: 94.8 ± 1.5%), high water-binding capacity (79.2 ± 2.8%) and significantly improved mechanical stability by EDC/NHS crosslinking (denaturation temperature: 74.6 ± 1.8 and 58.1 ± 2.6°C, respectively, for the crosslinked scaffolds and the non-crosslinked; collagenase degradation rate: 39.5 ± 3.4 and 63.5 ± 2.0%, respectively, for the crosslinked scaffolds and the non-crosslinked). The CII/HyA–CS scaffolds also showed satisfactory cytocompatibility and histocompatibility as well as low immunogenicity. These results indicate CII/HyA–CS scaffolds may be an alternative material for NP tissue engineering due to the similarity of its composition and physico-chemical properties to those of the extracellular matrices (ECM) of native NP.