Changes in membrane lipid order by microplasma irradiation for high molecule drug absorption

Plasma irradiation for drug delivery has attracted significant attention due to its advantages over conventional delivery methods. However, the underlying mechanism of plasma-mediated drug delivery remains largely unexplored. Cell membranes are mainly composed of lipid bilayer which can be easily affected by plasma components, such as reactive species. However, the effects of microplasma irradiation on cell membrane lipids have not been studied before. Therefore, the current study investigated the changes in the lipid packing of cell membranes after microplasma irradiation. In this study, we first optimized the conditions for high molecular weight drug (fluorescein isothiocyanate-dextran, Mw:150 kDa and 2000 kDa) absorption into intestinal epithelial cells. Air microplasma discharge at several voltages (3.5 kV, 4 kV, and 4.5 kV) was applied, and drug absorption was confirmed using a fluorescence microscopy and microplate reader. The best results were achieved at 4 kV in terms of both drug absorption and cell viability. Next, the lipid packing of the membrane was investigated in microplasma irradiated cells (at 4 kV) using lipiORDER dye. The results showed that the membrane lipid order has changed from liquid order phase to liquid disorder phase due to plasma irradiation. The findings of the current study will help understanding the mechanism of cellular drug absorption using microplasma irradiation.