Composite chondroitin-6-sulfate/dermatan sulfate/chitosan scaffolds for cartilage tissue engineering

Conjugating a single glycosaminoglycan (GAG) species such as chondroitin-6-sulfate (CSC) to chitosan is beneficial to chondrocyte culture and extracellular matrix (ECM) production, but whether fabrication of 3D chitosan scaffolds with additional minor GAG species such as dermatan sulfate (DS) further improves the ECM production is unknown. In this study, Response Surface Methodology (RSM) was employed to design CSC/DS/chitosan scaffolds of various formulations for cartilage engineering and to investigate the roles of individual GAG species in cartilage formation. The CSC/DS formulation affected neither the physical properties of scaffolds nor cell adhesion, but influenced cell morphology, GAGs and collagen production and chondrocytic gene expression. The linear effects elucidated by RSM analysis suggested that within the level range higher CSC levels favored GAGs and collagen production, whereas lower DS levels were desired for these responses. Nonetheless, the quadratic effects of DS and two-way interactions between CSC and DS also contributed to the GAGs and collagen production. Accordingly, the optimal formulation, as predicted by RSM and validated by experiments, comprised 2.8 mg CSC and 0.01 mg DS per scaffold. This study confirmed the importance of DS in cartilage tissue engineering and implicated the feasibility of rational CSC/DS/chitosan scaffold design with the aid of RSM.