Photodynamic/Phtothermal Synergisitic AntitΜmor Therapy And Imaging Reaserch Based On Graphene Oxide/Gold Nanostars

Recently, construction of safe, efficient and versatile nanomedicine with nanotechnology provides a good platform for cancer diagnosis and treatment. Photodynamic therapy(PDT) and photothermal therapy(PTT) are relatively new, safe and effective modaties based on the respective singlet oxygen and photothermal effect. Fabrication of photo-active nanocomplex for PDT and PTT combination therapy as well as imaging is a promising strategy in the area of nanobiomedicine. Especially, to achieve one single wavelength laser controlled-nanocomplex with reduced irradiation time and laser power density became a major chanlenge for photo-theranostics.In this thesis, a kind of photo-active nanocomplex GO-AuNS/PEG/Ce6 was constructed and its combinated PDT and PTT anticancer efficiency as well photoascostic imaging had been investigated. GO-AuNS was firstly synthesized by the method of in-situ growth of gold nanostar(AuNS) on graphene oxide(GO) temperate. The results of UV-visible and TEM showed that AuNS(c.a. 40nm) were well dispersed on thesurface of GO.Then HS-PEG5000-NH2 was utilized to functionlize the GO-Au NS nanohybrid to improve its stability and 1H NMR and TGA results confirmed the successful connection of PEG. The obtained GO-AuNS/PEG nanocomposites showed good biocompatibility(in vitro hemolysis rate was below 10%). Furthermore, GO-AuNS/PEG owned excellent photthermal conversion capability and can act as a good photoacoustic imaging constrast agent due to its broad near infread absorption. To achieve the combination therapy of PTT and PDT, photosensitizer Ce6 was loaded on GO-AuNS/PEG through π-π stacking and GO-AuNS/PEG/ce6 showed considerable ability of singlet oxygen generation. GO-Au NS/PEG/Ce6 nanocomplex could easily entered into EMT-6 cancer cells and it showed remarkablely enhanced anticancer efficiency of PDT and PTT as demonstrated by the CCK-8 cytocoxicity assay. Subsequent analysis of the lysosomes destruction and mitochondria membrane potential further validate the synergistic therapy of PDT and PTT mediated by GO-AuNS/PEG/Ce6. A series of assay against EMT-6 tumor model including the tumor volum, tumor weight, tuomor grow curve and H&E staining further demonstated that the GO-AuNS/PEG/Ce6 nanocomposite has excellent synergistic antitumor capacity in vivo.In a word, the designed GO-AuNS/PEG/Ce6 showed great promise as a single wavelength controlled photoactive nanomedicine for cancer diagonisis and trerapy.