Copper functionalized poly (acrylic acid-co-itaconic acid) nanohydrogel: Its antibacterial properties on oral pathogens and biocompatibility

Although extensive efforts have been made to explore effective antibiotics, the development of antibiotics lags far behind the emergence of drug-resistant bacteria. Antimicrobial materials as an alternative strategy provide effective functions in aiding in relieving the dose of antibiotics. Herein, we report a novel antibacterial agent with high antibacterial effectivity and low toxicity, which is simply composed of a trace amount of Cu2+ ion and nanoscale biocompatible polymer poly (acrylic acid-co-itaconic acid) (PAI-Cu). The polymer shows greatly enhanced antibacterial activity against various Gram-positive and Gram-negative pathogens compared with equal concentrations of copper ion solution, yet shows nearly no toxicity towards human cells. The antibacterial performance and mechanism of copper ionized polymer hydrogel are evaluated in terms of multiple methods, towards various oral bacteria including Streptococcus mutans, Enterococcus faecalis, Lactobacillus acidophilus, Actinomycetes viscosus, Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Prevotella intermedia. Bacterial cell membrane and wall damage caused by PAI-Cu nanohydrogel should be regarded as an important antibacterial mechanism. Moreover, PAI-Cu nanohydrogel, as the role of catalytic active center, can activate the surrounding oxygen, and generate hydroxyl radical (·OH), which can destroy the proliferation ability of microbial cells. We suggest that PAI-Cu nanohydrogel is a promising antibacterial agent against dental pathogens and beyond.