title: Enhanced protein loading into liposomes by the multiple crossflow injection technique.
abstract: Methods for encapsulation of a drug into liposomes should preferably result in a high encapsulation efficiency and a high encapsulation capacity. Our studies were focussed on the establishment of an efficient encapsulation procedure of the radical scavenging protein, rh-Cu/Zn-SOD, into liposomes with the cross flow injection method. Limitations to increase the encapsulation efficiency are caused by the enclosed aqueous volume, by the lipid concentration, the aspired vesicle size and the final ethanol concentration. Our research was performed to maximize the encapsulation following several strategies of injecting higher lipid concentrations into the aqueous phase. The one way triple technique, a sophisticated preparation procedure is presented, which enables three times higher encapsulation rates in comparison to standard procedures. Additionally, scalability studies demonstrate reproducibility independent of the preparation volume. Vesicle size distribution and encapsulation efficiency remain constant. Furthermore, special attention is paid on reproducibility of prepared liposomes, scale-up and on long term stability of the lipid vesicles.
authors.affiliation: Institute of Applied Microbiology, University of Agricultural Sciences, A-1190 Vienna, Austria. wagner@edv2.boku.ac.at
authors.forename: Andreas
authors.initials: A
authors.lastname: Wagner
authors.forename: Karola
authors.initials: K
authors.lastname: Vorauer-Uhl
authors.forename: Günther
authors.initials: G
authors.lastname: Kreismayr
authors.forename: Hermann
authors.initials: H
authors.lastname: Katinger
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002021:Buffers; D002626:Chemistry, Pharmaceutical; D002784:Cholesterol / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry; D004355:Drug Stability; D004867:Equipment Design; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008081:Liposomes / Q000032:analysis / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D015203:Reproducibility of Results; D013482:Superoxide Dismutase / Q000032:analysis / Q000737:chemistry*; D013678:Technology, Pharmaceutical; D015032:Zinc / Q000737:chemistry
chemical_list: D000588:Amines; D002021:Buffers; D004337:Drug Carriers; D008081:Liposomes; D011994:Recombinant Proteins; D015060:1,2-Dipalmitoylphosphatidylcholine; D003300:Copper; D002784:Cholesterol; D013482:Superoxide Dismutase; C009317:stearylamine; D015032:Zinc