Stem cell tracking using effective self-assembled peptide-modified superparamagnetic nanoparticles.

Superparamagnetic iron oxide nanoparticles (SPIONs) have been developed as excellent magnetic resonance imaging (MRI) contrast agents for stem cell labeling and tracking due to their biocompatibility. In this study, we designed a self-assembled peptide amphiphile (PA) with potential use in tissue engineering and drug delivery applications. This PA was conjugated to the surfaces of SPIONs to label rat mesenchymal stem cells (MSCs), which enhanced their contrast and labeling efficiencies. Studies on the labeled cells showed that the peptide-SPIONs had improved internalization, efficiency and T2-weight relaxivity both in vivo and in vitro and were nontoxic to the MSCs. The results demonstrated that these self-assembled peptide-modified SPIONs are potential candidates to label MSCs for tracking stem cells using MRI in vivo.