Preparation and Application of Sustained-Release Antibacterial Alginate Hydrogels by Loading Plant-Mediated Silver Nanoparticles

Silver nanoparticles (AgNPs) are broad-spectrum antibacterial agents that are safe for the environment and the human body. To achieve a balance between material functionality, degradability, and safety of AgNPs, the peanut red skin (PSE)/polyphenol-hydroxypropyl-β-cyclodextrin (HPβCD)/AgNPs were prepared for the first time by ultrasound-triggered molecular encapsulation and biosynthesis for hydrophilic fusion of medicine and small molecules. Additionally, a novel "controlled release" sodium alginate (SA)-based hydrogel was developed and medicine/small-molecule self-assembled PSE/HPβCD/AgNPs were introduced into the three-dimensional network structure of the SA hydrogels. The SA-based hydrogels exhibited excellent mechanical and rheological properties. In different pH conditions, the hydrogels exhibit differing release and expansion behaviors, and the maximum cumulative release of AgNPs was 98.21% at pH > 6.8. Furthermore, the hydrogels exhibited strong antibacterial effects against pathogenic bacteria. They also showed excellent antioxidant properties and cytocompatibility. These advantages highlight the potential utility of the developed hydrogels for biomedical applications and agricultural fields.