Ultrasmall graphene oxide based T1 MRI contrast agent for in vitro and in vivo labeling of human mesenchymal stem cells

A graphene oxide (GO)-based T1 magnetic resonance imaging (MRI) contrast agent, GO-DOTA-Gd, has been developed for in vitro and in vivo labeling of human mesenchymal stem cells (hMSCs). Conjugation of GO with Gd complex, we demonstrated, leads to significantly improved MRI signal, and therefore significantly enhanced cellular signal intensity in T1-weighted MR images, without obvious adverse effects on the viability, growth, and differentiation of hMSCs. Moreover, 5 × 105 hMSCs labeled with GO-DOTA-Gd can be visualized clearly after implanted into nude mice, making it promising to monitor the location, migration and survival of the implanted hMSCs in regenerative medicine.161