title: Targeting of lysosomes by liposomes modified with octadecyl-rhodamine B.
abstract: The use of lysosome-targeted liposomes may significantly improve a delivery of therapeutic enzymes into lysosomes for the treatment of lysosome-associated diseases. The aim of this research was to achieve a specific intracellular targeting of lysosomes, by using liposomes modified with the lysosomotropic octadecyl-rhodamine B (RhB) and loaded with a model compound, fluorescein isothiocyanate (FITC)-dextran (FD). Plain and RhB-modified liposomes were prepared by hydration of lipid films and loaded with FD or with 5-dodecanoylaminofluorescein di-β-d-galactopyranoside (C(12)FDG), a specific substrate for the intralysosomal β-galactosidase. The delivery of these liposomes and their content to lysosomes in HeLa cells was investigated by confocal microscopy, flow cytometry, and subcellular fractionation. Confocal microscopy demonstrated that RhB-liposomes co-localize well with the specific lysosomal markers, unlike plain liposomes. The comparison of the FITC fluorescence of the lysosomes isolated by subcellular fractionation also showed that the efficiency of FD delivery into lysosomes by RhB-modified liposomes was significantly higher compared with plain liposomes. These results were additionally confirmed by the flow cytometry of the intact cells treated with C(12)FDG-loaded liposomes that also demonstrated increased lysosomal targeting by RhB-modified liposomes. The modification of the liposomal surface with a lysosomotropic ligand, such as octadecyl-RhB, can significantly increase the delivery of liposomal loads to lysosomes.
authors.affiliation: Department of Pharmaceutical Sciences, Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Koshkaryev
authors.forename: Ritesh
authors.initials: R
authors.lastname: Thekkedath
authors.forename: Cinzia
authors.initials: C
authors.lastname: Pagano
authors.forename: Igor
authors.initials: I
authors.lastname: Meerovich
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Torchilin
mesh_terms: D018929:Cell Culture Techniques; D003470:Culture Media; D003911:Dextrans / Q000008:administration & dosage; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives; D005452:Fluoresceins / Q000008:administration & dosage; D005697:Galactosides / Q000008:administration & dosage; D006367:HeLa Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes; D008247:Lysosomes / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010316:Particle Size; D012235:Rhodamines / Q000737:chemistry*; D013499:Surface Properties
chemical_list: C503505:5-dodecanoylaminofluorescein; D003470:Culture Media; D003911:Dextrans; D004337:Drug Carriers; D005452:Fluoresceins; D005697:Galactosides; D008055:Lipids; D008081:Liposomes; D012235:Rhodamines; C015219:fluorescein isothiocyanate dextran; C425723:octadecylrhodamine B; C038848:fluorescein-digalactoside; D016650:Fluorescein-5-isothiocyanate