Preliminary in vitro study of ultrasound sonoporation cell labeling with superparamagnetic iron oxide particles for MRI cell tracking.

Vibration caused by ultrasonic waves can change the structure of cell membrane and enhance its permeation. In the last decade, a new ultrasound-aided method, sonoporation, has been proposed and utilized to transmit target molecules (such as drugs and DNA) into cells for therapy. The objective of this study was to investigate the method of loading nanometer-sized superparamagnetic iron oxide particles into Sarcoma 180 cells by sonoporation without chemical agents. The SPIO nanoparticles were prepared in our laboratory by means of classical coprecipitation and the formation of Fe3O4 crystal in SPIO nanoparticles was confirmed by x-ray diffraction analysis with its other characteristics assessed by magnetic hysteresis loops and size distribution. Cell labeling with SPIOs using sonoporation was successfully demonstrated in vitro for sarcoma180 cell suspensions from ICR mice. The labeling efficiency and viability were evaluated by Prussian blue staining. Such sonoporation technique can be employed for rapid labeling of various cells for MRI visualization of their spatiotemporal activities in vivo upon transplantation.