Construction of MPDA@IR780 nano drug carriers and photothermal therapy of tumor cells

The combination of chemotherapy and photothermal therapy can provide better tumor treatment effect than monotherapy, while the combination of imaging technology can achieve diagnostic effect during the treatment. In this paper, biocompatible mesoporous polydopamine (MPDA) were combined with the near-infrared fluorescent dye IR780 under alkaline condition to form an integrated drug delivery platform for tumor diagnosis and photothermal co-therapy. The particles size and mesoporous pore size of the nanospheres were adjusted by changing the preparation conditions of MPDA, so the platform had strong permeability and large drug loading capacity in tumor cells as drug carriers. The loading and release results of doxorubicin hydrochloride (DOX) proved that the carrier had a high drug loading and sustained release rate, as well as a faster dependent release under acidic and lighting conditions. Photothermal experiments showed that the carrier had high photothermal conversion efficiency, which was very critical in its application in photothermal therapy and fluorescence imaging of tumors. The vitro cytotoxicity test evaluated the survival rates of LX-2 cells and HepG2 cells after drug loading. The results showed that the MPDA@IR780-DOX + NIR carrier had a significant inhibitory effect on HepG2 cells (12.57%), but had little effect on LX-2 cells, which was beneficial for its application in integration of biological diagnosis and treatment.