Abstract #1889

Remote MR Sensing of PH and Cell Viability Using LipoCEST-Filled Microcapsules

Kannie W. Y. Chan^1,2, G. Liu^1,3, D.R. Arifin^1,2, J. W.M. Bulte^1,2, M.T. McMahon^1,3

¹Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; ²Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; ³F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Cell transplantation is widely used for treatment of various diseases, with cell viability being key for successful therapy. Semi-permeable microcapsules have been used to immunoprotect and visualize cell location, but not cell function. We demonstrate that LipoCEST-filled microcapsules can be used as a novel way to monitor cell viability. CEST contrast is dependent on pH, which in itself is closely related to cell activity and functionality. Our pH-responsive microcapsules showed a significant decrease in CEST signal when cell viability decreased at physiologically relevant pHs, thus representing a useful non-invasive tool to monitor successful cell therapy.