Construction Of Graphene-based Nanocomposite For Near-infrared Induced Anti-cancer Effect Of Cancer Therapy

Currently, it becomes an imperative requirement to develop a new and non-traditional therapeutic approach to treat cancers efficiently because conventional methods have many disadvantages. Photothemal therapy(PTT) and photodynamic therapy(P DT) are two new photo-therapies based on photothemal effect and ROS reaction and owe the merits of high selectivity, noninvasiveness, and efficiency. Particularly, near- infrared light(NIR) mediated PTT and PDT is being attached enormous attention, since NIR has low absorption by biological tissue and can penetrate deep tissue. On the other hand, nanographene oxide(GO) has great potential in biomedicine due to their highly enriched physical and chemical properties, such as well biocompatibility, high surface ratio, rich oxygen-containing functional groups, easy functionalization. Therefore, study of NIR-responsive nanomedicine based on GO for PTT and PDT combination therapy is being considered as a promising strategy to high efficiently and non-invasively treat cancer.In this thesis, a kind of NIR active nanocomplex based on GO was developed for cancer synergistic PTT and PDT therapy. In brief, GO-CuS nanohybrides were synthesized through hydrothermal method, and stabilized with amphiphilic mPEG-DSPE. C haracterization results of TEM, AFM, TGA, XRD, EDX and UV-vis-NIR showed that a large amount of CuS nanoparticles were dispersed on GO with a diameter of about 15nm; and hexahedral crystals. The height of PEG/GO-CuS is mainly in 30-40 nm. Compared with GO, PEG/GO-CuS had a strong absorption in NIR, and an obvious temperature elevation effect when inradiated by 940 nm NIR laser. PEG/GO-CuS/ICG could load NIR photosensitizer IC G through ?-? stacking with the maximum efficiency of 180%. When loaded with ICG, PEG/GO-CuS had a redshift absorption peak and the floerescence of ICG was quenched. PEG/GO-CuS/ICG could generate 1O2 effectively when irradiated with an 808 nm laser. PEG/GO-CuS/ICG can easily and efficiently transported into cells and localized mainly in mitochondria. The pathway of PEG/GO-CuS/ICG was most likely via non-energy-dependent passive diffusion across cell membranes. Moreover, in vitro biological results demenstrated that PEG/GO-CuS/ICG can efficiently kill cancer cells such as breast cancer MCF-7 cells through the effect of single PTT and PDT, and these therapies were power density dependent. When irradiated with 940 nm and 808 nm laser sequently, obvious synergistic anticancer efficiencies were obtained amoug MCF-7 cells.This study demonstrate that the nanocomposite PEG/GO-CuS/ICG haseffectively in vitro synergistic anti-tumor effect with the combination of PTT and PDT, which highlightes the promise of PEG/GO-CuS/ICG for NIR- induced PTT and PDT phototherapy for high efficient cancer treatment.