Engineered mesenchymal stem cells for targeting solid tumors: Therapeutic potential beyond regenerative therapy

Mesenchymal stem cells (MSCs) have previously demonstrated considerable promise in regenerative medicine based on their ability to proliferate and differentiate into cells of different lineages. More recently, there has been a significant interest in using MSCs as cellular vehicles for targeted cancer therapy by exploiting their tumor homing properties. Initial studies focused on using genetically modified MSCs for targeted delivery of various proapoptotic, antiangiogenic, and therapeutic proteins to a wide variety of tumors. However, their use as drug delivery vehicles has been limited by poor drug load capacity. This review discusses various strategies for the nongenetic modification of MSCs that allows their use in tumor-targeted delivery of small molecule chemotherapeutic agents.