Nanotechnology as an adjunct tool for transplanting engineered cells and tissues

Laboratory and clinical studies have provided evidence of feasibility, safety and efficacy of cell transplantation to treat a wide variety of diseases characterized by tissue and cell dysfunction ranging from diabetes to spinal cord injury. However, major hurdles remain and limit pursuing large clinical trials, including the availability of a universal cell source that can be diffesirentiated into specific cellular phenotypes, methods to protect the transplanted allogeneic or xenogeneic cells from rejection by the host immune system, techniques to enhance cellular integration of the transplant within the host tissue, strategies for in vivo detection and monitoring of the cellular implants, and new techniques to deliver genes to cells without eliciting a host immune response. Finding ways to circumvent these obstacles will benefit considerably from being able to understand, visualize, and control cellular interactions at a sub-micron level. Cutting-edge discoveries in the multidisciplinary field of nanotechnology have provided us a plafform to manipulate materials, tissues, cells, and DNA at the level of and within the individual cell. Clearly, the scientific innovations achieved with nanotechnology are a welcome strategy for enhancing the generally encouraging results already achieved in cell transplantation. This review article discusses recent progress in the field of nanotechnology as a tool for tissue engineering, gene therapy cell immunoisolation, and cell imaging, highlighting its direct applications in cell transplantation therapy.