没食子酸改性氧化石墨烯光热治疗微针的制备与评价OA

Objective To prepare a photothermal therapeutic microneedle for the treatment of age-related chloasma that in-hibits melanin secretion,and to evaluate its performance and efficacy.Methods GAGO nanocomposites were prepared by modifying the graphene oxide(GO)structure with gallic acid(GA);the synthesis of GAGO was verified using UV-Vis spectrophotometry and Fourier transform infrared spectroscopy;the stability of GO and GAGO in aqueous solution,PBS and RPMI 1640 medium was detected using a Malvern particle sizer;three matrix materials,chitosan,poly-vinyl pyrrolidone(PVP),and polyvinyl alcohol,were screened and the micromolding perfusion method was determined.Their topography was characterized using light microscopy and scanning elec-tron microscopy;mechanical properties of microneedles were tested using an Instronnstron compression-tension tester;skin insertion properties of microneedles were tested using SD rat skin;photothermal conversion properties of microneedles were assessed by an 808 nm near-infrared(NIR)laser;and the in vitro inhibitory effect of GAGO photothermal therapy was verified using B16 melanoma cells.Results GA was successfully loaded on GO and had good stability and physicochemical properties.GAGO-PVP microneedles were successfully constructed,with beautiful appearance,easy pouring and demoulding,intact needle tips without bubbles,and through mechanical properties testing,the loss of efficacy reached 3.66 N/needle,which can penetrate the skin without causing inflam-mation,and has good photothermal conversion properties.Compared with the control group,GAGO could significantly increase the ac-tivity of B16 melanoma cells,decrease tyrosinase activity and inhibit melanin secretion during NIR challenge,and the differences were statistically significant(P<0.001).Conclusion GAGO NIR treatment significantly inhibited B16 melanoma cell viability and mela-nin secretion,and GAGO-PVP microneedles have the potential to be applied in melasma treatment.