Objective: Layer-by-layer self-assembly was used to modify magnetic tungsten disulfide(mWS₂), thus a stable drug loading platform under physiological conditions was built. It had a targeted drug delivery property and synergistic effect on cancer cells through photo-chemotherapy.  Methods: mWS₂ was prepared by solvothermal method, and then positively charged chitosan and negatively charged sodium carboxymethyl cellulose were layer-by-layer deposited in the water system respectively to prepare chitosan/carboxymethyl cellulose sodium modified magnetic tungsten disulfide composite material (mWS₂-CS/CMC). Series of structural characterizations was performed on the synthesized materials and, and its photothermal properties as well as its drug loading and release behavior was studied. In addition, in vitro cell photochemotherapy combined treatment plan was designed, at the same time to its cell uptake and cytotoxicity was examined. Results: The synthesized mWS₂-CS/CMC was superparamagnetic with good stability and high drug loading profile. The drug release assay showed a dual response release to pH and NIR. In addition, it has low toxicity and can be taken up by MCF-7 cells, and produce an excellent therapeutic effect on the combination of photo-chemotherapy on cancer cells. Conclusion: The mWS₂-CS/CMC is an excellent drug carrier and can also be used as a photothermal agent for photothermal therapy and combination therapy.

［Key words］WS₂; magnetic nanoparticles; surface modification; layer-by-layer self-assembly; photothermal therapy; combined therapy; drug carrier

Objective: To prepare cerium doped carbon quantum dots (Ce-doped CDs) with efficient photothermal ablation for the photothermal treatment of breast cancer cell. Methods: Ce-doped CDs were prepared by microwave-assisted hydrothermal carbonization with cerium oxalate and glycine as precursors. The morphology was characterized by high power transmission electron microscopy. Fluorescence spectra were used to characterize its fluorescence properties. Near-infrared thermal imager was used to characterize the photothermal conversion efficiency. The photothermal killing effect of Ce-doped CDs was verified with 4T1 breast cancer cells in vitro. Results: Ce-doped CDs with uniform morphology, particle size of about 2.6 nm and good biocompatibility were successfully prepared, which had excellent fluorescence performance and photothermal conversion efficiency. As the concentration of Ce-doped CDs increased, 4T1 cell activity decreased under specific near-infrared light irradiation (808 nm), and normal cells had greater photothermal tolerance than tumor cells. Conclusion: Ce-doped CDs with fluorescence property and photothermal conversion efficiency were successfully prepared. The prepared Ce-doped CDs can effectively convert near-infrared light energy into heat energy, thus effectively kill tumor cells.

［Key words］cerium doped carbon quantum dots; photothermal therapy; carbon quantum dots; breast cancer cell; fluorescence; cell viability; photothermal ablation

Objective: To fabricate a nanoparticle with the combination effect of chemotherapy, photothermal therapy and photodynamic therapy. Furthermore, its antimultidrug-resistant tumor effects in vitro were evaluated. Methods: DOX-HIT-NPs were self-assembled through the intrinsic interaction between D-α-tocopherol succinate (TOS), human serum albumin (HSA), indocyanine green (ICG) and Doxorubicin (DOX). The morphology and particle size were characterized. MCF-7/ADR cells were employed to investigate the cellular uptake of DOX-HIT-NPs. Fluorescence microscopy was used to observe the level of reactive oxygen species (ROS) in MCF-7/ADR cells. The cytotoxicity of DOX-HIT-NPs was detected by CCK8 assay. Results: The prepared DOX-loaded HIT-NPs were approximately spherical with particle size of 278.8 nm. It produced a good photothermal effect. DOX-HIT-NPs could promote the cellular uptake of DOX in MCF-7/ADR cells. Under laser irradiation, DOX-HIT-NPs could induce ROS generation and result in a significant inhibition effect against MCF-7/ADR cells. Conclusion: DOX-HIT-NPs were obtained successfully, and DOX-HIT-NPs had the effect of reversing tumor multidrug resistance in vitro.

［Key words］tumor multidrug resistance； combination therapy; chemotherapy; photothermal therapy; photodynamic therapy; albumin; indocyanine green; tocopherol