Lysozyme-Based Hydrogels: Molecular Assembly, Structural Engineering, and Multifunctional Applications

Lysozyme (LZM) is a naturally occurring antimicrobial protein. LZM can hydrolyze peptidoglycans in bacterial cell walls, and can also exert non-enzymatic antibacterial effects by interacting with bacterial membranes. Beyond its intrinsic biological activity, LZM can participate in hydrogel network formation or serve as a precursor for amyloid fibril assembly, making it both a bioactive component and a structural building block. This review summarizes the preparation strategies and multifunctional applications of LZM-based hydrogels. These strategies include physical and supramolecular assembly, amyloid fibril formation, covalent crosslinking, and hybrid network construction. Depending on network design, these strategies can impart properties such as injectability, self-healing, tissue adhesion, and stimuli responsiveness. LZM hydrogels have shown potential for infection control and wound healing through antibacterial activity, biofilm inhibition, and support for tissue repair. As a drug delivery carrier, LZM hydrogels have been investigated for the delivery of antibiotics, growth factors, and anticancer drugs. LZM hydrogels have also been explored in bone, corneal, and cardiac tissue engineering. In addition, LZM hydrogels incorporating molecular imprinting or functionalized components have shown potential applications in biosensing and food preservation. However, challenges remain in maintaining enzymatic activity, evaluating long-term biological safety, and ensuring reproducible material preparation. Further clarification of structure–function relationships and standardized performance evaluation will be important for the practical development of LZM hydrogels.