Preparation of cationic polyelectrolyte grafted polyvinyl alcohol-formaldehyde macroporous hydrogels and their antibacterial properties

Antibacterial hydrogels have the effects of creating a moist and cool environment for wound healing and decreasing infection of microbes, along with providing high water vapor permeability. Based on the functions of antibacterial hydrogels, macroporous PVF-g-PDMC cationic hydrogels, as one form of these hydrogels, were successfully synthesized via redox initiated [2-(methacryloyloxy)ethyl]-trimethyl ammonium chloride (DMC) grafting onto polyvinyl alcohol-formaldehyde (PVF) sponges. The interconnected pore channels of the as-prepared hydrogels, with a macroporous structure and high porosity of around 90%, conferred the hydrogels with remarkable water absorption capacity of up to 20 g g−1, achieved in ten seconds. Notably, the as-prepared hydrogels can kill Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. aureus) bacteria significantly, with a reduction of six orders of magnitude compared with the high initial concentration of bacteria (108 CFU mL−1), which indicates their excellent antibacterial properties. Moreover, the hemolysis and cytocompatibility studies confirmed the safety and biocompatibility of the hydrogels. Besides this, these PVF-based hydrogels also displayed prominent mechanical properties and their cyclic stress–strain curves demonstrate their good reusability. Considering their high porosity and extraordinary water absorption capacity of up to 20 g g−1 in ten seconds, antibacterial properties, low hemolysis rates and good cytocompatibility, prominent mechanical properties and good reusability, PVF-g-PDMC hydrogels are promising candidates as desirable antibacterial materials related to biomedical materials.