Study On The Application Of CuS NDs-based Composite Hydrogel In Antibacterial

With the emergence of drug-resistant bacteria,bacterial infections will pose a serious threat to human health.Diseases caused by bacteria or wound infections that could be easily cured by antibiotics in the past can be fatal because of the development of resistance,and bacteria that are resistant to all known antibiotics have emerged.With the widespread inappropriate use of antibiotics,it has become common knowledge that more resistant bacteria will emerge.Therefore,it is urgent to actively develop therapies and systematic treatment systems that do not generate bacterial resistance.Method: In this study,we successfully synthesized CuS Nanodots(CuS NDs for short)and loaded them into F127 hydrogel to prepare a composite hydrogel containing CuS NDs,namely CuS NDs-hydrogel.It was characterized by transmission electron microscope(TEM),particle size potential analyzer,micro plate spectrophotometer,etc.;then,we studied the photothermal and photodynamic antibacterial effects of CuS NDs and CuS NDs-hydrogel through bacterial biofilm inhibition and elimination experiments,coating experiments,and live/dead staining experiments in vitro.The research results are as follows:(1)The material characterization results showed that CuS NDs were dispersed with a hydrated particle size of 10± 1.2 nm and an average particle size of about 5 nm by TEM.In addition,the nanodot has excellent particle size stability,light stability,biocompatibility and photodynamic performance,which lays a solid foundation for the antibacterial experiment;(2)The coating experiment and the live/dead dyeing experiment confirmed the near-infrared CuS NDs-hydrogel could effectively inhibit the growth of bacteria after NIR light irradiation,and its concentration had a significant impact on the survival rate of bacteria.The minimum inhibitory concentration for S.aureus/E.coli is 1 mg/m L.It shows that CuS NDs-hydrogel has a good antibacterial effect after near-infrared laser irradiation;(3)The ability of CuS NDs-hydrogel to eliminate biofilm was tested,and the results showed that the results show that when the concentration of the composite hydrogel reaches 1 mg/m L under near-infrared light irradiation,the composite hydrogel could not only effectively inhibit the formation of bacterial biofilm,but also eliminate the biofilm already generated,and the bactericidal and biofilm inhibiting ability of this material is different from the mechanism of traditional antibiotic sterilization,indicating that it has great bactericidal ability and its ability to inhibit biofilm formation are different from traditional antibiotics,indicating its potential for widespread use.In addition,cellular experiments have demonstrated that CuS NDs-hydrogel is non-cytotoxic and can promote cell migration,which is expected to accelerate the wound healing process of bacterial infections.