Comparison of liposome fusion and electroporation for the intracellular delivery of nonpermeant molecules to adherent cultured cells.

Intracellular delivery of nonpermeant molecules to cultured cells in situ can be problematic. This work is a comparison between two methods of accomplishing this delivery; liposome-mediated delivery and electroporation. The final goal was to examine the effects of the glutathione S-transferase (GST) inhibitor Basilen Blue (BB) on glyceryl trinitrate biotransformation in porcine kidney epithelial (PK1) cells after intracellular delivery. Initial evaluation used the fluorescent markers carboxyfluorescein and lucifer yellow (LY). This was followed by biochemical analysis of glyceryl trinitrate biotransformation. Liposome-mediated delivery proved ineffective in spite of variations in the lipid composition of the liposomes and the use of an agglutinin and a fusogen. In contrast, electroporation was a very effective method for intracellular delivery of both lucifer yellow and basilen blue to the PK1 cells. The results show that in cells where Basilen Blue was introduced, there was a decrease in both the glyceryl trinitrate (GTN) biotransformation and ratio of glyceryl-1,2-dinitrate (1,2-GDN) to glyceryl-1,3-dinitrate (1,3-GDN) formed. The technique of in situ electroporation shows great promise for the assessment of a variety of nonpermeant molecules of pharmacological interest.