MoS2-based nanocomposites with high photothermal conversion efficiency for combinational photothermal/photodynamic tumor therapy

Photothermal conversion efficiency (PCE) plays a crucial role in tumor photothermal therapy (PTT). In this work, we developed a MoS2-based antitumor agent with enhanced photothermal conversion efficiency by size/morphology tailoring and IR820 loading for combinational photothermal/photodynamic therapy (PTT/PDT) of breast cancer. Among three MoS2-based nanomaterials, namely MoS2 nanospheres (NSs), MoS2 nanoflowers (NFs) and MoS2 quantum dots (QDs), MoS2 NSs possessed the highest PCE at 37.48%. In order to further improve the PCE, polyethyleneimine (PEI)-assisted photosensitizer IR820 decoration was carried out to prepare the MoS2@PEI@IR820 (MPI) nanocomposite. The introduced IR820 not only improves PCE of the MoS2 nanomaterials to 47.08% by increasing the light absorption for enhancing PTT, but produces cytotoxic ROS for PDT, resulting in a combinational PTT/PDT with the multifunctional MPI. In addition, in vivo fluorescence (FL) bioimaging and infrared thermographic imaging have been achieved by the designed MPI nanoplatform, which has proven to be good biocompatibility, low toxicity and high PCE. This study provides a novel way for the design and construction of prominent theragnostic nanoagents for combinational PTT/PDT.