Hybrid hydrogels based on polyvinyl alcohol, branched polyethylenimine, polydopamine, and phosphonium-based ionic liquid for effective synergetic antibacterial applications

Exploring effective and sustainable antibacterial agents to combat the bacterial contamination of cultural-heritage objects is an important issue. In this work, inspired by the broad applications of hydrogels in the biomedical field, a hybrid hydrogel was fabricated from the supramolecular assembly of polyvinyl alcohol (PVA), branched polyethylenimine (PEI), polydopamine nanoparticles (PDA NPs), and a phosphonium-based ionic liquid (IL), which was denoted as PVA-PDA@PEI-IL. Branched polycationic PEI interacted electrostatically with the negatively charged bacterial membranes, ultimately resulting in cell lysis and death. The released phosphonium-based IL disrupted the bacterial membranes and subsequently eradicated adhered and nearby bacteria. Although the PDA NPs displayed a high photothermal conversion efficiency, local hyperthermia did not appear to enhance the antibacterial activity of the prepared hydrogel. In addition, we also verified the significant antibacterial activity of the resulting hydrogel against the bacterial biofilms that adhered to the different substrate material surfaces. Therefore, our work presented the possibility of potential applications of these antibacterial hydrogels for cultural heritage conservation.