Effects of cross‐linking with EDC/NHS and genipin on characterizations of self‐assembled fibrillar gel prepared from tilapia collagen and alginate

• Published in: Polymer degradation and stability 2022-06, Vol.200, p.109929, Article 109929
• Main Authors: Yan, Mingyan, An, Xiangsheng, Jiang, Zhicong, Duan, Shujun, Wang, Ailing, Zhao, Xiaochen, Li, Yinping
• Format: Article
• Language: English
• Subjects: Alginate; Alginates; Biocompatibility; Biomedical materials; Bonding strength; Characterization; Chemical reactions; Chemisorption; Collagen; Cross-linking; Crosslinking; Crosslinking polymerization; Curve fitting; EDC/NHS; Gels; Genipin; Hydrogen bonds; Structural integrity; Thermal stability; Tilapia
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2022.109929

•Cross-linking with EDC/NHS and genipin was controlled by monolayer chemisorption.•Genipin endowed fibrillar gel with much higher cross-linking degree than EDC/NHS.•After introducing EDC/NHS, fibril bundles were present in gels, similar to control.•Genipin induced the disaggregation of fibril bundles in gels after cross-linking.•Spindle-like cells appeared in SA/PSC/Genipin, while rounded ones in SA/PSC/EDC/NHS. Chemical cross-linking is prevalent for precise control of the properties of collagen-based materials. However, there is little information about detailed comparisons of cross-linking characteristics of collagen-based fibrillar gel with different cross-linkers. In this study, a fibrillar gel was prepared from tilapia collagen and alginate, and cross-linking conditions with EDC/NHS and genipin were discussed. By curve-fitting with Langmuir and pseudo-second-order model, the cross-linking process was controlled by monolayer chemisorption, and genipin showed much higher cross-linking degree at saturation compared with EDC/NHS. ATR-FTIR and XPS suggested that although hydrogen bonds were weakened by cross-linking, EDC/NHS offered short-range cross-linking formed by amino and carboxyl groups in fibrils, while genipin induced long-range cross-linking by interactions of amino groups in fibrils and ester groups in genipin. XRD and SEM revealed that the structural integrity was strengthened after cross-linking, however, fibril bundles were present in SA/PSC/EDC/NHS, and genipin induced disaggregation of fibrils. Both swelling properties and enzymatic resistance were improved by cross-linking, while thermal stability was unenhanced significantly. All fibrillar gels showed good biocompatibility, but cross-linking degree affected appearance and migration of cells. The results revealed that genipin-cross-linked fibrillar gel had greater potential application in biomaterials on the premise of tuning cross-linking degree than EDC/NHS-cross-linked one.