Structurally Adjustable Eugenyl-Based Quaternary Phosphonium Cation Degradable Antibacterial Nanomaterials via RAFT

In this study, using bio-based eugenol as the basic polymerization unit, the directional coupling of quaternary phosphonium cations and eugenol was achieved through covalent bonding, and a new type of degradable antibacterial monomer (Eu-PH) was successfully synthesized. Notably, cubic nanoparticles were obtained via the self-assembly of Eu-PH during its homopolymerization, whereas spherical nanoparticles were generated when Eu-PH was copolymerized with <i>N</i>-vinylpyrrolidone (NVP). This structural transformation not only induced significant changes in the material's physicochemical properties but also markedly enhanced its antibacterial efficacy. Experimental results demonstrated that PH_<i>x</i>-PVP_<i>y</i> achieved inhibition rates of 100% against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, with a relative biocompatibility of 99% toward L-929 cells. In addition, PH_<i>x</i>-PVP_<i>y</i> exhibited excellent degradability and fruit preservation performance. In brief, by virtue of structural regulation of bio-based eugenol and NVP, a promising new approach is proposed for the development of antibacterial materials that simultaneously possess high antibacterial activity, good biocompatibility, and satisfactory degradability.