Magnetic resonance imaging of stem cell apoptosis in arthritic joints with a caspase activatable contrast agent. ACS nano Nejadnik, H., Ye, D., Lenkov, O. D., Donig, J. S., Martin, J. E., Castillo, R., Derugin, N., Sennino, B., Rao, J., Daldrup-Link, H. 2015; 9 (2): 1150-1160

Abstract

About 43 million individuals in the U.S. encounter cartilage injuries due to trauma or osteoarthritis, leading to joint pain and functional disability. Matrix-associated stem cell implants (MASI) represent a promising approach for repair of cartilage defects. However, limited survival of MASI creates a significant bottleneck for successful cartilage regeneration outcomes and functional reconstitution. We report an approach for noninvasive detection of stem cell apoptosis with magnetic resonance imaging (MRI), based on a caspase-3-sensitive nanoaggregation MRI probe (C-SNAM). C-SNAM self-assembles into nanoparticles after hydrolysis by caspase-3, leading to 90% amplification of (1)H MR signal and prolonged in vivo retention. Following intra-articular injection, C-SNAM causes significant MR signal enhancement in apoptotic MASI compared to viable MASI. Our results indicate that C-SNAM functions as an imaging probe for stem cell apoptosis in MASI. This concept could be applied to a broad range of cell transplants and target sites.

View details for DOI 10.1021/nn504494c

View details for PubMedID 25597243