*Article* **Opening the Blood Brain Barrier with an Electropermanent Magnet System**

**Sahar Jafari <sup>1</sup> , Ittai S. Baum <sup>1</sup> , Oleg G. Udalov <sup>1</sup> , Yichien Lee <sup>2</sup> , Olga Rodriguez 2,3, Stanley T. Fricke 2,3,4 , Maryam Jafari <sup>5</sup> , Mostafa Amini <sup>6</sup> , Roland Probst <sup>7</sup> , Xinyao Tang <sup>1</sup> , Cheng Chen <sup>1</sup> , David J. Ariando <sup>8</sup> , Anjana Hevaganinge <sup>1</sup> , Lamar O. Mair <sup>1</sup> , Christopher Albanese 2,3,4 and Irving N. Weinberg 1,\***


**Abstract:** Opening the blood brain barrier (BBB) under imaging guidance may be useful for the treatment of many brain disorders. Rapidly applied magnetic fields have the potential to generate electric fields in brain tissue that, if properly timed, may enable safe and effective BBB opening. By tuning magnetic pulses generated by a novel electropermanent magnet (EPM) array, we demonstrate the opening of tight junctions in a BBB model culture in vitro, and show that induced monophasic electrical pulses are more effective than biphasic ones. We confirmed, with in vivo contrast-enhanced MRI, that the BBB can be opened with monophasic pulses. As electropermanent magnets have demonstrated efficacy at tuning B0 fields for magnetic resonance imaging studies, our results suggest the possibility of implementing an EPM-based hybrid theragnostic device that could both image the brain and enhance drug transport across the BBB in a single sitting.

**Keywords:** blood brain barrier; electropermanent magnet; magnetic resonance imaging
