The Antibacterial Activity Of Mussels-inspired Nanoparticle-hydrogel Composites

Polymer hydrogels play an important role in vitro antibacterial activity because of the excellent mechanical properties,water retention,and the tunable structure and properties.In this article,inspired by the distinct adhesion capability of mussels on wet surfaces,dopamine methacrylamide(DMA)monomer was designed based on the catechol group in DMA,the polymer hydrogels were synthesized via free-radical polymerization,and adhered onto the surface of nanoparticles via the mussel-inspired“Graft to”approach.The stable nanoparticle-hydrogel composites presented excellent antibacterial properties and recyclability.In the first work,The poly(DMA-co-ADMH-co-HEMA)copolymer(DAH)was synthesized via radical copolymerization of dopamine methacrylamide(DMA),3-allyl-5,5-dimethylhydantoin(ADMH),and hydroxyethyl methacrylate(HEMA),The phenolic hydroxyl groups from N-halamine copolymers are used for ligand exchange with oleic acid on the magnetic Fe₃O₄ nanoparticles for binding the N-halamine copolymer onto the surface of the nanoparticles.After the nanoparticles are uniformly coated by the hydrogel with a semi-interpenetrating network structure,the core-shell structure hydrogel nanoparticle(Fe₃O₄@DAH)are stable and prevent the nanoparticles from being further oxidized.After the chlorination treatment,the hydantoin groups of DAH transform to N-halamine structure,and the final products Fe₃O₄@DAH-Cl nanoparticles formed.As expected,the prepared Fe₃O₄ nanoparticles provided an indispensable role for the recyclability of the material,and dopamine crosslinked N-halamine copolymer provided the material antibacterial properties,More importantly,the magnetic performance of the as-prepared nanoparticles allow them easily separable from aqueous solution by external magnets and reusable in antibacterial applications.Thanks to the excellent adhesion capability of dopamine and its derivatives,nanoparticle-hydrogel composites have widely been used in various fields.Inspired by the work above,the copolymer(DAD)was synthesized via radical copolymerization of dopamine methacrylamide(DMA),acrylic acid(AA)and 2-(dimethylamine)ethyl methacrylate(DMAEMA),The polymer hydrogel was cross-linked by chemical bonds and physical entanglement,Ag⁺were penetrated into the polymer network by soaking and spontaneous redox reaction occured between the hydrogel and Ag⁺.DMAEMA and nano-silver play a synergistic antibacterial effect.Therefore,nanoparticle-hydrogel presented excellent antibacterial activity.The interpenetrating network structure with copolymer and Ag⁰ made nanoparticle-hydrogel present good recovery.In addition,the nanoparticle-hydrogel was formed without adding reducing agent.The pore structure of the hydrogel provides a good space for the growth of nano-silver,making it evenly distributed and preventing the nanoparticles from being further oxidized.The nanoparticle-hydrogel with broad-spectrum antibacterial effect expected to be used in biomedical engineering.