caa a22 4500 477126227 CHVBK 20180405111650.0 cr unu---uuuuu 170330e19970901xx s 000 0 eng 10.1023/A:1012158924547 doi (NATIONALLICENCE)springer-10.1023/A:1012158924547 Cellular Retention of Liposome-Delivered Anionic Compounds Modulated by a Probenecid-Sensitive Anion Transporter [Elektronische Daten] [Yu-Kyoung Oh, Robert Straubinger] Purpose. Drug carriers such as liposomes may enhance the intracellular delivery of therapeutic agents for infectious or neoplastic diseases. However, the mechanisms affecting cellular retention of liposome contents are understood poorly. We tested the hypothesis that retention of anionic compounds may be modulated by a nonspecific probenecid-sensitive anion transport mechanism, and that liposome composition may determine the impact of such transporters on drug retention by cells. Methods. The fluorescent anionic dye hydroxy-pyrene-[ 1,3,6]-trisulfonate (HPTS) was transferred to the cytoplasm of cultured CV-1 or J774 cells by direct needle-microinjection or by ATP-induced permeabilization of the plasma membrane, respectively, to investigate whether the cells have anion transport mechanisms capable of extruding HPTS from the cytoplasm. Cellular retention of dye was monitored in the presence and absence of the anion transport inhibitors probenecid or sulfinpyrazone. Liposomes containing HPTS were co-labeled with tetramethylrhodamine-labeled phosphatidylethanolamine (Rho-PE) as a marker of liposome membrane fate, and uptake was investigated using J774 cells. Results. Needle-injected HPTS underwent both sequestration in early endocytic vesicles and rapid extrusion into the extracellular medium. Probenecid or sulfinpyrazone reduced the extrusion of HPTS. Thus HPTS is a substrate for a probenecid-sensitive anion transporter in J774 and CV1 cells. After delivery via fluid liposomes composed of phosphatidylglycerol: phosphatidylcholine: cholesterol (3:7:5 mole ratio) and co-labeled with Rho-PE, cell-associated HPTS declined more rapidly than did Rho-PE. Exposure of cells to 5 mM probenecid doubled the quantity of HPTS retained by cells, without changing the retention of the Rho-PE membrane marker. In contrast, the effect of probenecid was negligible when gel-phase liposomes of distearoylphosphatidyl-glycerol:cholesterol (10:5 mole ratio) were used. Conclusions. Probenecid-sensitive nonspecific anion transporters can mediate the extrusion of model anions delivered via liposomes. However, liposome composition modulates the amount of material subject to extrusion from cells, possibly by altering the endocytic compartment in which liposomes release their contents. Plenum Publishing Corporation, 1997 intracellular drug delivery nationallicence drug carriers nationallicence liposomes nationallicence probenecid-sensitive anion transporter nationallicence Oh Yu-Kyoung The Department of Pharmaceutics, State University of New York Amherst, 539 Cooke Hall, University at Buffalo, 14260-1200, New York aut Straubinger Robert The Department of Pharmaceutics, State University of New York Amherst, 539 Cooke Hall, University at Buffalo, 14260-1200, New York aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/9(1997-09-01), 1203-1209 0724-8741 14:9<1203 1997 14 11095 https://doi.org/10.1023/A:1012158924547 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012158924547 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Oh Yu-Kyoung The Department of Pharmaceutics, State University of New York Amherst, 539 Cooke Hall, University at Buffalo, 14260-1200, New York aut NATIONALLICENCE 700 1- Straubinger Robert The Department of Pharmaceutics, State University of New York Amherst, 539 Cooke Hall, University at Buffalo, 14260-1200, New York aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/9(1997-09-01), 1203-1209 0724-8741 14:9<1203 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer