The construction of a seaweed-based antibacterial membrane loaded with nano-silver based on the formation of a dynamic united dual network structure

Abstract

In order to obtain a medical hydrogel membrane material with excellent mechanical properties and antibacterial ability, we loaded silver nanoparticles (AgNPs) into a calcium alginate–polydopamine–carboxymethyl chitosan (CA–PDA–CMCS) membrane with a united dual network structure. Based on the reducibility of PDA and the metal-binding ability of catechol, an algal-based hydrogel membrane (Ag@CA–PDA–CMCS membrane) with outstanding mechanical and antibacterial properties was prepared. As a reducing agent, PDA was reacted with AgNO₃ to generate AgNPs, which is a superior method to eliminate the residual toxic reducing agent particles and improve the biocompatibility of composite materials. When the content of dopamine (DA) was 0.75 wt%, the comprehensive performance of the CA–PDA–CMCS membrane was the best. The tensile strength and elongation at break were 91.92 MPa and 2.55%, respectively, which were increased by 342.99% and 13.84% compared with those of the CA membrane. The Ag@CA–PDA–CMCS membrane showed obvious antibacterial properties against Escherichia coli and Staphylococcus aureus. The cytotoxicity of the Ag@CA–PDA–CMCS membrane was the least when the AgNO₃ concentration was 2 mM. The Ag@CA–PDA–CMCS membrane has great potential for use in the field of new wound dressings.