Comparison of the properties of collagen-chitosan scaffolds after γ-ray irradiation and carbodiimide cross-linking

The property of collagen-chitosan porous scaffold varies according to cross-linking density and scaffold composition. This study was designed to compare the properties of collagen-chitosan porous scaffolds cross-linked with gamma-irradiation and carbodiimide (CAR) for the first time. Eleven sets of collagen-chitosan scaffolds containing different concentrations of chitosan at a 5% increasing gradient were fabricated. Fourier transform infrared spectroscopy was performed to confirm the success of cross-linking in the scaffolds. The scaffold morphology was evaluated under scanning electron microscope (SEM). SEM revealed that chitosan was an indispensable material for the fabrication of gamma-ray irradiation scaffold. The microstructure of gamma-ray irradiation scaffold was less stable than those of alternative scaffolds. Based upon swelling ratio, porosity factor, and collagenase degradation, gamma-ray irradiation scaffold was less stable than CAR and 25% proportion of chitosan scaffolds. Mechanical property determines the orientation in gamma-irradiation and CAR scaffold. In vitro degradation test indicated that gamma-irradiation and CAR cross-linking can elevate the scaffold biocompatibility. Compared with gamma-ray irradiation, CAR cross-linked scaffold containing 25% chitosan can more significantly enhance the bio-stability and biocompatibility of collagen-chitosan scaffolds. CAR cross-linked scaffold may be the best choice for future tissue engineering.