Michael K. Nkansah1, Durga Thakral1, Erik M. Shapiro, 12
1Department of Biomedical Engineering, Yale University, New Haven, CT, United States; 2Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States
Magnetic cell labeling has primarily been accomplished using dextran-coated iron-oxide nanoparticles. A drawback to their use is the low iron content per particle, coupled with cessation of commercial production. As an alternative, micron-sized iron-oxide particles (MPIOs) have been used, the benefits of which are that they contain ~ 30% iron. The downside is that MPIOs are composed of inert, non-degradable and not FDA-approved polymers, potentially limiting clinical utility. Here we demonstrate the fabrication of fluorescent, biodegradable MPIOs, composed of PLGA and cellulose, two FDA-approved polymers. These particles have high relaxivity and are capable of labeling cells for MRI-based cell tracking.