Local gene targeting and cell positioning using magnetic nanoparticles and magnetic tips: comparison of mathematical simulations with experiments.

PURPOSE

Magnetic nanoparticles (MNPs) and magnets can be used to enhance gene transfer or cell attachment but gene or cell delivery to confined areas has not been addressed. We therefore searched for an optimal method to simulate and perform local gene targeting and cell delivery in vitro.

METHODS

Localized gene transfer or cell positioning was achieved using permanent magnets with newly designed soft iron tips and MNP/lentivirus complexes or MNP-loaded cells, respectively. Their distribution was simulated with a mathematical model calculating magnetic flux density gradients and particle trajectories.

RESULTS

Soft iron tips generated strong confined magnetic fields and could be reliably used for local (~500 μm diameter) gene targeting and positioning of bone marrow cells or cardiomyocytes. The calculated distribution of MNP/lentivirus complexes and MNP-loaded cells concurred very well with the experimental results of local gene expression and cell attachment, respectively.

CONCLUSION

MNP-based gene targeting and cell positioning can be reliably performed in vitro using magnetic soft iron tips, and computer simulations are effective methods to predict and optimize experimental results.