Feasibility study of the natural derived chitosan dialdehyde for chemical modification of collagen

•The biocompatible OCS is prepared successfully for the modification of collagen.•The more stable Schiff's base is formed between collagen and OCS.•The OCS inherits chitosan's superior antibacterial activity.•Introducing OCS into collagen may be favorable for the cell's adhesion, growth and proliferation.•The effect of OCS on the fibrillogenesis of collagen was also analyzed in detail. The aim of this study is to evaluate the chemical crosslinking effects of the natural derived chitosan dialdehyde (OCS) on collagen. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and circular dichroism (CD) measurements suggest that introducing OCS might not destroy the natural triple helix conformation of collagen but enhance the thermal-stability of collagen. Meanwhile, a denser fibrous network of cross-linked collagen is observed by atomic force microscopy. Further, scanning electron microscopy (SEM) and aggregation kinetics analysis confirm that the fibrillation process of collagen advances successfully and OCS could lengthen the completion time of collagen fibrillogenesis but raise the reconstitution rate of collagen fibrils or microfibrils. Besides, the cytocompatibility analysis implies that when the dosage of OCS is less than 15%, introducing OCS into collagen might be favorable for the cell's adhesion, growth and proliferation. Taken as a whole, the present study demonstrates that OCS might be an ideal crosslinker for the chemical fixation of collagen.