A Novel Double‐Crosslinking‐Double‐Network Design for Injectable Hydrogels with Enhanced Tissue Adhesion and Antibacterial Capability for Wound Treatment

• Published in: Advanced functional materials Vol. 30; no. 1
• Main Authors: Wang, Lei, Zhang, Xuehui, Yang, Kun, Fu, Yu Vincent, Xu, Tianshun, Li, Shengliang, Zhang, Dawei, Wang, Lu‐Ning, Lee, Chun‐Sing
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2020
• Subjects: Adhesion; antibacterial capability; Biocompatibility; Biodegradability; Carbon; Catechol; Chelation; Chitosan; Crosslinking; Design modifications; double‐crosslinking‐double‐network; Fibrin; Hydrogels; Imidazole; Materials science; Mechanical properties; Modulus of elasticity; Network design; Oxidation; photocrosslinkable and injectable chitosan; Quinones; Shear strength; Skin; tissue adhesion; Tissues; Wound healing
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201904156

Most photocrosslinkable hydrogels have inadequacy in either mechanical performance or biodegradability. This issue is addressed by adopting a novel hydrogel design by introducing two different chitosan chains (catechol‐modified methacryloyl chitosan, CMC; methacryloyl chitosan, MC) via the simultaneous crosslinking of carbon–carbon double bonds and catechol‐Fe3+ chelation. This leads to an interpenetrating network of two chitosan chains with high crosslinking‐network density, which enhances mechanical performance including high compressive modulus and high ductility. The chitosan polymers not only endow the hydrogels with good biodegradability and biocompatibility, they also offer intrinsic antibacterial capability. The quinone groups formed by Fe3+ oxidation and protonated amino groups of chitosan polymer further enhance antibacterial property of the hydrogels. Serving as one of the two types of crosslinking mechanisms, the catechol‐Fe3+ chelation can covalently link with amino, thiol, and imidazole groups, which substantially enhance the hydrogel's adhesion to biological tissues. The hydrogel's adhesion to porcine skin shows a lap shear strength of 18.1 kPa, which is 6‐time that of the clinically established Fibrin Glue's adhesion. The hydrogel also has a good hemostatic performance due to the superior tissue adhesion as demonstrated with a hemorrhaging liver model. Furthermore, the hydrogel can remarkably promote healing of bacteria‐infected wound. A novel photocrosslinkable, injectable, and tough chitosan hydrogel demonstrating a remarkable improvement in tissue adhesion and antibacterial activity is fabricated via double crosslinking (blue light crosslinking and catechol‐Fe3+ chelation) and double network design, suggesting that it can be promising as wound dressing for cutaneous tissue repair, remodeling, and regeneration.