Mesenchymal stem cell intracellular labeling using silica-coated superparamagnetic iron oxide nanoparticles with amine functional peripheries

Two types of superparamagnetic iron oxide nanoparticles designed for mesenchymal stem cell labeling and magnetic resonance imaging in vivo tracking were constructed in our laboratories. Both types of nanoparticles have an iron oxide core and a thin layer of silica coating, one of them has additional surface modification with amine. The overall particle size was around 8 nanometers. The in vitro study results demonstrated that, without the application of a transfection agent, both nanoparticles could be incorporated into bone marrow derived mesenchymal stem cells and located in lysosomes. Surface modification with amine significantly increased mesenchymal stem cell labeling efficiency, leading to an increased magnetic resonance imaging detection sensitivity of 2-5 folds.