Self-assembled superparamagnetic nanocomposite-labelled cells for noninvasive, controlled, targeted delivery and therapy

Efficient delivery of cells to targeted sites at optimal concentrations within rational limits of damage to normal tissue is a major challenge for cell delivery. With the help of magnetic nanoparticles binding to the surface of cells, it is possible to manipulate and control cell mobility using an external magnetic field. Here, we demonstrate physical entrapment of magnetic nanocomposites onto cell surfaces and their manipulation by an external magnetic field. Uniformly embedded nano iron oxide particles in a hydroxyapatite crystallite (HAIO) were synthesized via co-precipitation method. Physiochemical and biological evaluation of the above nanocomposite system showed that the HAIO containing 50 wt% iron oxide (HAIO50) possessed excellent magnetic properties and good cytocompatibility. Prussian blue staining and flow cytometric evaluation of cell-material interactions indicated uniform uptake and a dose-dependent interaction. HAIO50 is found to be a novel matrix for use as an effective and cytocompatible avenue for cell separation, evidenced via Coulter analysis as well as fluorescent imaging of live cells. Post-magnetic separation analysis of cell viability via confocal laser scanning microscopy (CLSM) showed the normal structure and proliferation of separated cells. HAIO50 may be used as an efficient matrix for magnetic non-invasive manipulation and for further cell delivery applications.