Collagen-based hydrogel sol-gel phase transition mechanism and their applications

Collagen-based hydrogels represent a crucial class of biomaterials for their desirable physicochemical and biochemical properties. The variation in ingredients, gelation conditions, and crosslinking techniques may impact the physicochemical and biological properties of collagen-based hydrogels. However, the specific effects of these parameters on the gelation mechanisms of novel hydrogels and the relationships between fabrication parameters and the resultant characteristics of these hydrogels remain elusive. This review discussed the sol-gel phase transition mechanisms of collagen-based hydrogels, emphasizing the impact of gelation conditions, crosslinking agents, and additional polymers. This article highlights the potential of natural ingredients and safe modification technologies as effective strategies to mitigate the harmful effects of synthetic toxic components in products. Furthermore, this review summarizes constitutive models of collagen hydrogels, which serve as valuable tools for designing and customizing hydrogels to meet specific application requirements by simulating their mechanical and rheological properties. Additionally, the article concludes by briefly introducing applications of novel collagen-based hydrogels with desirable functions and properties. This review further deals with the theoretical support for the rational design and customization of innovative hydrogels and inspires future collagen-based biomaterial development.