The Preparation Of Agarose-based Composite Hydrogel And Its Antibacterial Properties

Nowadays,photothermal killing of pathogenic bacteria and treatment of wound infection have attracted great attention owing to effectively avoiding the drawbacks of traditional antibiotics.In this paper,agarose hydrogels with photothermal effect were prepared by a facile and eco-friendly strategy.The photothermal properties,photothermal sterilization and biocompatibility were studied.(1)Photothermal sterilizationAn agarose(AG)-based hydrogel containing tannic acid-Fe(III)(TA-Fe)nanoparticles was fabricated by a facile and eco-friendly strategy.The optimal nanocomposite hydrogel showed the good mechanical property and superior processability.More importantly,the nanocomposite hydrogel revealed outstanding photothermal effect,which exhibited a sharp temperature increase of 58 °C during NIR exposure for 10 min.With in vitro antibacterial experiment,the hydrogel could effectively kill of nearly 99% of bacteria with 10 min of NIR irradiation.Additionally,for the in vivo experiment,the nanocomposite hydrogel could effectively cure wound infection and promote wound healing.Moreover,the hydrogel possessed high biocompatibility.Based on the good mechanical property,outstanding photothermal effect and high biocompatibility,the nanocomposite hydrogel could become a promising antibacterial wound dressings for biomedical applications.(2)Synergistic antibacterial effect with photothermal effect and antibioticsWe used the agarose(AG)hydrogel to encapsulate ferric tannate(TF)nanoparticles(NP,photothermal material)and vancomycin(Van,antibiotic)to fabricate a photothermal-sensitive hybrid hydrogel as a novel wound dressing(VAT hydrogels).Importantly,the hybrid hydrogel exhibits outstanding photothermal properties under the irradiation of low-intensity near-infrared light.And the low-intensity NIR light not only can induce the photothermal TF nanoparticles to generate local hyperthermia but also can promote the release of the antibiotics as a precise “on/off” trigger.The synergistic way integrates the spatiotemporal control of antibiotics release and hyperthermia to inactivate microbes.Moreover,the ability to control when and where the drug is releasing via photoactivation of low-intensity decreases the local effective drug accumulation and minimizes the phototoxic adverse effects.The antibacterial effect of silver nanoparticles was achieved by combining the antibacterial effect of silver nanoparticles withphotothermal sterilization.The light-activatable hybrid hydrogels with the precise release of antibiotics and efficient elimination of bacteria will be a promising material for skin-associated bacterial infections.(3)The combinational antibiosis of photothermal effect and silver nanoparticlesAn agarose hydrogel containing silver nanoparticles was prepared as wound dressing.The nanocomposite hydrogel showed significant photothermal effect.And the temperature rose sharply under the irradiation of 808 NIR for 10 min.With in vitro antibacterial experiments,the hydrogel without the exposure of NIR showed the antibacterial properties by virtue of the bactericidal properties of silver nanoparticles.What's more,the hydrogel can effectively kill above 99% bacteria after 10 min of near infrared irradiation.The hydrogel also showed the excellent antibacterial and wound healing effects in vivo.In addition,in vivo experiments,nanocomposite hydrogels could effectively treat wound infections and promote wound healing.