title: Encapsulation of the cobra cytotoxin P4 in liposomes.
abstract: Cytotoxin P4 isolated from the venom of the cobra Naja nigricollis nigricollis was encapsulated in liposomes by the reverse-phase evaporation method using phosphatidylcholine, cholesterol and phosphatidylethanolamine at molar ratios of 3:1:1. Cytotoxicity examination on murine melanoma B16F10 revealed that the activity of the entrapped cytotoxin did not change significantly and remained stable for at least 1 year at 4 degrees C without any significant leak from the liposomes (< 1%). Moreover, the activity of the cytotoxic liposomes was 20-fold higher towards human erythrocytes. Whereas 45 micrograms of the free cytotoxin/ml were needed for total haemolysis, the cytotoxic liposomes brought about the same effect at cytotoxin concentrations of 2-2.5 micrograms/ml, indicating the potential of the liposomes as a delivery system for the snake toxin.
authors.affiliation: Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Chaim-Matyas
authors.forename: G
authors.initials: G
authors.lastname: Borkow
authors.forename: M
authors.initials: M
authors.lastname: Ovadia
mesh_terms: D000818:Animals; D016923:Cell Death; D004337:Drug Carriers; D004339:Drug Compounding; D004546:Elapid Venoms / Q000737:chemistry / Q000633:toxicity*; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008081:Liposomes; D008546:Melanoma, Experimental; D051379:Mice; D014407:Tumor Cells, Cultured
chemical_list: D004337:Drug Carriers; D004546:Elapid Venoms; D008081:Liposomes; C077896:cytotoxin P4