Low targeting efficiency limits the applications of nanoparticles in cancer therapy.The fact that mesenchymal stem cells (MSC) trapped in the lung after systemic infusion is a disadvantage for cell therapy prrposes.Here,we utilized MSC as lung cancer-targeted drug delivery vehicles by loading nanoparticles (NP) with anti-cancer drug.MSC showed a higher drug intake capacity than fibroblasts.In addition,MSC showed predominant lung trapping in both rabbit and monkey.IR-780 dye,a fluorescent probe used to represent docetaxel (DTX) in NP,delivered via MSC accumulated in the lung.Both in vitro MSC/A549 cell experiments and in vivo MSC/lung cancer experiments validated the intercellular transportation of NP between MSC and cancer cells.In vivo assays showed that the MSC/NP/DTX drug delivery system exerted primary tumor inhibition efficiency similar to that of a NP/DTX drug system.Collectively,the MSC/NP drug delivery system is promising for lung-targeted drug delivery for the treatment of lung cancer and other lung-related diseases.