Enhancement of T2-weighted MR contrast using heparin for cell tracking in vivo

Abstract

Superparamagnetic iron oxide (SPIO) nanoparticle has emerged as a novel probe for noninvasively cellular tracking using magnetic resonance imaging. Here we developed SPIO nanoparticles coated with biocompatible heparins, i.e., low-molecular-weight-heparin (LMWH) or unfractionated heparin (UFH). These heparin-SPIO nanoparticles showed good crystallizability and stability without self-aggregation for 50 days. Also, UFH-SPIO nanoparticle had lower relaxation time with higher relaxivity. Moreover, they were efficiently internalized into cells without cytotoxicity and had faster saturated magnetization. Furthermore, the implanted SPIO nanoparticles-labeled Ins-1 cells were strongly visualized in vivo MR imaging. Collectively, heparin-based SPIO nanoparticles could have a great potential for in vivo cellular tracking.