Chitosan–Fish Scale Collagen/Glycerin 3D Porous Scaffold EDAC/NHS Cross-Linking: Effects on the Microstructure, Physicochemical Properties, and Cytocompatibility

The three-dimensional porous architecture of scaffolds strongly influences cell infiltration and cell–cell and cell–matrix interactions. The mechanical strength and biostability of three-dimensional (3D) porous scaffolds remain challenges for maintaining the 3D porous architecture and facilitating cell infiltration and cell–cell and cell–matrix interactions. In this study, the mechanical strength and biostability of chitosan–fish scale collagen 3D porous scaffolds were improved by using EDAC/NHS cross-linking in the presence of glycerin. Furthermore, the microstructure, physicochemical properties, mechanical strength, biostability, and cytocompatibility of the scaffolds were investigated. Chitosan–fish scale collagen/glycerin 3D porous scaffolds were fabricated via the EDAC/NHS cross-linking. Cross-linking effects on scaffold microstructures and physicochemical properties were investigated, while the scaffolds’ mechanical strength and biostability were determined by using mechanical and biodegradation tests. Cytocompatibility tests were used to explore the ability of 3D porous scaffolds to be used for tissue engineering applications. The scaffolds’ cross-linking density/degree, tensile modulus, and biostability were increased and pore size decreased with EDAC/NHS cross-linking treatment, resulting in enhanced mechanical strength and biostability of the 3D porous architecture of the scaffolds. The average tensile modulus of the cross-linking scaffold in a dry environment was in a range of 4.61 ± 2.33–0.62 ± 0.13 MPa, with a tensile modulus in a wet environment of 25.2 ± 6.32–17.74 ± 6.00 KPa, a biodegradation rate at day 30 of 28.73 ± 4.58–26.014 ± 1.70, and average pore sizes of 151.33 ± 53.66–142.31 ± 60.67 μm. In vitro culture of human fibroblasts and keratinocytes showed that the mechanical strength and biostability of cross-linking scaffolds supported cell proliferation, adhesion, spreading, and infiltration. It was found that the EDAC/NHS treatment improved the mechanical strength and biostability of the chitosan–fish scale collagen 3D porous architecture in the presence of glycerin and enhanced the cytocompatibility of scaffolds.