CuS Composite Thermosensitive Nanospheres for Combined Treatment of Tumor Photothermal and Chemodynamic Therapy

In the study,a kind of CuS nano-particleswith photothermal conversion properties was prepared.The precipitation polymerization method used N-isopropylacrylamide(NIPAAm)and N-vinylpyrrolidone(NVP)as comonomers,and lithium laponite was used as a crosslinking agent to adsorb nano-CuS for preparing a composite microgel P(NIPAAm-co-NVP)/CuS(NNC/CuS)with both photothermal effect and temperature-sensitive response.The drug loading release performance were tested.The experimental results showed that the prepared nano-CuS and NNC/CuS composite microgels had a wide spectral absorption band in the near-infrared region(NIR).Under the conditions of 980 nm(0.51 W/)laser irradiation,the NNC/CuS composite microgels had a good effect.The temperature rose to 51.9°C within 8 min,the effect of killing HeLa cells was obvious,and it was proportional to the laser irradiation time.The drug loading of the composite microgel was 0.15 mg/mg,and the cumulative drug release in the PBS buffer at pH=5.5 was 75%,which was higher than 63%at pH=7.4.At the same time,the photothermal effect can effectively regulate the drug release of the temperature-sensitive drug-loaded microspheres.In the drug release stage,the drug release rate of the laser irradiation section was significantly higher than that of the laser irradiation section.In addition,the combination of polymer and CuS improved the toxicity to cells.The cell survival rate of NNC/CuS composite microgel is 90.9%higher than that of CuS(63%).