Preparation And Antitumor Performance Of Noble Metal Nanoparticles Based On Daptomycin

Cancer is seriously harmful for people's lives and health.In recent years,photothermal therapy has shown good anti-tumor properties.Noble metal nanoparticles are good photothermal agents.However,noble metal photothermal agents have problems such as low stability and low photothermal conversion efficiency.To overcome these problems,this article took gold,silver,and palladium noble metal nanoparticles as the research object;amphiphilic daptomycin was used to regulate the morphology,particle size and stability of three kinds of noble metal nanoparticles.The photothermal conversion ability,cytotoxicity and anti-tumor ability of the noble metal nanoparticles were studied.The effect of daptomycin on enhancing the photothermal properties of noble metal nanoparticles was clarified.The main contents and conclusions are as follows:?1?Gold nanoflowers?Dap-Au₆NFs?with about 80 nm were successfully prepared using the amphiphilic daptomycin self-assembled micelles in aqueous solution as templates.Dap-Au₆NFs exhibited a wide absorption band in the near infrared region and an absorption peak at 632 nm,and its light-to-heat conversion efficiency was as high as40%.Dap-Au₆NFs showed good therapeutic and inhibitory effects on tumors and bacteria under the irradiation of 808 nm near infrared light.After laser treatment for 10 min,the tumor inhibition rate was as high as 87.7%,the bacterial inhibition rates of S.aureus and E.coli were 64%and 52%,respectively.In vivo experiments in mice showed that after 10days of photothermal treatment,the tumor volume of mice in the[Dap-Au₆NFs+laser]group decreased from 40 mm³ to 0.78 mm³.?2?Palladium nanoflowers?Dap-PdNFs?with size of about 106 nm were prepared by stepwise reduction of sodium tetrachloropalladium and using daptomycin micelle as a template.Dap-PdNFs had high absorbance in the range of 400?1000 nm,and their light-to-heat conversion efficiency was as high as 38%.In the absence of laser irradiation,the cell activities of He La cells and HT-29 cells on Dap-PdNFs were bigger than 95%,and under the irradiation of 808 nm near infrared light,the temperature of Dap-PdNFs solution rapidly heated from 26.8?to 52.0?within 10 min,the tumor inhibition rate of Dap-PdNFs was up to 71.2%.?3?Silver nanoparticles?Dap-AgNPs?with size of 138 nm were prepared using sodium borohydride to reduce silver nitrate and daptomycin to enhance their stability.Dap-AgNPs had good aqueous solution stability and photothermal stability,the thermal conversion efficiency was also as high as 36.8%.Dap-AgNPs that were not irradiated in the near-infrared showed almost no cytotoxicity to HeLa cells and HT-29 cells.The Dap-AgNPs solution irradiated with 808 nm near-infrared light rapidly heated up from 25?to 47?within 10 min.The inhibition rate of Dap-AgNPs on He La cells was as high as 80%.