Progress in hydrogel toughening: addressing structural and crosslinking challenges for biomedical applications

Achieving the ideal replacement for robust biological tissues requires biocompatible materials with a nuanced blend of characteristics, including organ specific toughness, durability, self-repairing capability, and a well-defined structure. Hydrogels, structured with high water containing 3D-crosslinked polymeric networks, present a promising avenue in biomedical applications due to their close resemblance to natural tissues. However, their mechanical performance often falls short, limiting their clinical applications. Recent research has been focused on developing biocompatible hydrogel materials for therapeutic applications. Recent advancements have spurred researchers to develop biocompatible hydrogels having acceptable mechanical toughness. While it is now possible to tailor the mechanical properties of synthetic gels to mimic those of natural tissues, critical aspects such as biocompatibility and crosslinking strategies are frequently neglected. This review scrutinizes the structural and crosslinking techniques designed to improve the toughness of hydrogels, focusing especially on innovative efforts to integrate these enhancements into natural-based hydrogels. By thoroughly examining these methodologies, the review sheds light on the complexities of strengthening hydrogels for biomedical applications and will propose valuable insights for the development of next-generation tissue substitutes.