Advances in Collagen-/Gelatin-Based Hydrogels: Rheological Properties and Applications

Owing to their tunable and biocompatible characteristics, collagen- and gelatin-based hydrogels have gained attention in numerous applications, including biomedical, food, pharmaceutical, and environmental. The gelation mechanisms and resulting network structures of collagen and gelatin differ significantly depending on the presence of intra- and intermolecular crosslinks. These differences enable the tailoring of mechanical properties to achieve desired characteristics in the final product. Mechanical gel strength and elasticity determine how effectively hydrogels can mimic natural tissues and respond to deformations. Probing the rheological properties of these gels enables a deeper understanding of their structure, physical attributes, stability, and release profiles. This review provides an in-depth evaluation of the factors affecting the mechanical strength of collagen- and gelatin-based hydrogels, highlighting the influence of co-molecules and the application of physical, chemical, and mechanical treatments. Herewith, it brings insights into how to manipulate the mechanical properties of these gels to improve their end-use functionality.