Polymyxin E biomineralized and doxorubicin-loaded gold nanoflowers nanodrug for chemo-photothermal therapy

Gold nanoparticles are a kind of good photothermal agents. However, gold nanoparticle photothermal agents have low photothermal conversion efficiency and low tumor inhibiting ability. To overcome these problems, polymyxin E (PE) biomineralized and doxorubicin-loaded gold nanoflowers (DOX-SH@AuNFs) nanodrug was synthesized by the green synthesis method using the biological antimicrobial peptide PE as a stabilizer and grower of crystal seed, and doxorubicin-thiol (DOX-SH) was further loaded on the gold nanoparticles through the Au-S bond. The final DOX-SH@AuNFs displayed a wide absorption band in the UV–Vis spectra, and their photothermal conversion efficiency was 33.9%. Furthermore, the inhibition rate of DOX-SH@AuNFs on A549 cells was as high as 80.1% under the irradiation of near-infrared light at 808 nm. The tumor inhibition rate of DOX-SH@AuNFs was as high as 87.81% in vivo experiments. The high tumor suppression rate was attributed to the high photothermal conversion ability of DOX-SH@AuNFs and the delivery of doxorubicin. Taken together, the method of preparing DOX-SH@AuNFs provides a new idea for the treatment of cancer by photothermal therapy and chemotherapy synergistic system.