Recent advances in cell-mediated nanomaterial delivery systems for photothermal therapy.

Nanomaterial-based photothermal therapy using near-infrared (NIR) light is a promising strategy for cancer treatment. However, delivery of nano-agents to specific tumor sites poses a great challenge, especially in the tumor hypoxia regions, where the hypoxia-associated drug delivery barriers prevent the effective intratumoral distribution of nanomaterials. In this respect, tumor-tropic cells including macrophages, monocytes, neural stem cells (NSCs), and mesenchymal stem cells (MSCs) have been proposed as "Trojan Horse" delivery vehicles to transport various nano-agents to overcome the drug delivery barriers, increase the tumor targeting ability of nano-agents, and enhance the efficiency of photothermal therapy. In this review, we summarize recent research activities and emerging trends in this field, describe the advantages of combining cellular therapies and nanotechnology to achieve more effective cancer treatment, and discuss the clinical prospects of photothermal therapy.