Tough polyelectrolyte hydrogels with antimicrobial property via incorporation of natural multivalent phytic acid

Abstract

Tough and antimicrobial dual-crosslinked poly((trimethylamino)ethylmethacrylate chloride)- phytic acid hydrogel (pTMAEMA-PA) has been synthesized by adding a chemical crosslinker and docking a physical crosslinker of multivalent phytic acid into a cationic polyelectrolyte network. By increasing the loading concentration of PA, the tough hydrogel exhibits compressive stress of > 1 MPa, alongwith high elasticity and fatigue-resistant properties. The enhancedmechanical properties of pTMAEMA-PA stem from the multivalent ion effect of PA via the formation of ion bridges within polyelectrolytes. In addition, a comparative study for a series of pTMAEMA-counterion complexes was conducted to elaborate the relationship between swelling ratio andmechanical strength. The study also revealed secondary factors, such as ion valency, ion specificity and hydrogen bond formation, holding crucial roles in tuning mechanical properties of the polyelectrolyte hydrogel. Furthermore, in bacteria attachment and disk diffusion tests, pTMAEMA-PA exhibits superior fouling resistance and antibacterial capability. The results reflect the fact that PA enables chelating strongly with divalent metal ions, hence, disrupting the outermembrane of bacteria, aswell as dysfunction of organelles, DNA and protein. Overall, the work demonstrated a novel strategy for preparation of tough polyelectrolyte with antibacterial capability via docking PA to open up the potential use of PA in medical application.