Effect of electromagnetic field on endocytosis of cationic solid lipid nanoparticles by human brain-microvascular endothelial cells

This study investigates the electromagnetic field (EMF)-regulated transport of cationic solid lipid nanoparticles (CSLNs) across human brain-microvascular endothelial cells (HBMECs). The positive charge of CSLNs was from dioctadecyldimethyl ammonium bromide and stearylamine, and radiofrequency EMF was applied to HBMECs for promoting uptake of CSLNs. Immunochemical staining revealed that the expression of clathrin on the membrane of HBMECs enhanced during vesicular endocytosis of CSLNs. However, CSLNs and EMF slightly affected the expression of P-glycoprotein on the membrane of HBMECs. An exposure to EMF yielded negligible increase in the permeability of free saquinavir (SQV) across the HBMEC monolayer. Nevertheless, the permeability of SQV across the HBMEC monolayer increased about 17-fold when SQV was entrapped in CSLNs. Moreover, the permeability of SQV across the HBMEC monolayer increased about 22-fold by applying the CSLN encapsulation and EMF exposure. CSLNs and EMF could produce synergistic effect on improving the brain-targeting delivery.