Structurally Heterogeneous Amphiphilic Conetworks of Poly(vinyl imidazole) Derivatives with Potent Antimicrobial Properties and Cytocompatibility

We report the construction of amphiphilic conetwork (APCN)-based surfaces with potent antimicrobial activity and biofilm inhibition ability. The construction strategy is based on the separation of lipophilic alkyl groups (>C6) from the cationic network to obtain good antibacterial properties. The reaction of partially alkylated poly(vinyl imidazole) with the activated halide compounds followed by coating a glass or poly(dimethylsiloxane) (PDMS) sheet leads to the formation of the APCN surface. The dangling alkyl chains, crosslinking junctions, and unreacted vinyl imidazole groups are heterogeneously distributed in the APCNs. The swelling, mechanical property, and phase morphology of the APCN films have been evaluated. Bacterial cell disrupting potency of the APCN coatings increases with increasing alkyl chain length from C6 to C18 with somewhat more of an effect on Escherichia coli as compared to Bacillus subtilis bacteria. The minimum inhibitory amount of the APCNs on glass and a hydrophobic PDMS surface is in the range of 0.02–0.04 mg/cm2 depending on the chain length of the alkyl and the degree of quaternization. The effect of the type of crosslinker for the construction of the conetwork on the antimicrobial property has been evaluated to elucidate the exclusive design of the APCNs. The APCN-based coatings provide potent biocidal activity without much negatively affecting the hemocompatibility and cytocompatibility. These APCNs provide a good model system for comparative evaluation of the biocidal property and structural effect on the biocidal activity.