Kevin S. Tang1, Erik M. Shapiro2
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 with MPIOs is well established, however, current protocols employ long labeling times. Incubation of negatively charged iron oxide nanoparticles with positively charged transfection agents, such as poly-l-lysine (PLL) increases labeling efficiency. Therefore, it was hypothesized that pre-incubating MPIOs with various quantities of PLL would similarly enhance the rate of magnetic cell labeling. Indeed, it was discovered that MPIO complexation with PLL yielded positive zeta potential. Furthermore, cells labeled with MPIO:PLL complexes were fully labeled after only two hours incubation, whereas negatively charged MPIOs labeled only 20%, even after four hours.