Liposomes

2021
Schilt Y, Berman T, Wei X, Nativ-Roth E, Barenholz Y, Raviv U. Effect of the ammonium salt anion on the structure of doxorubicin complex and PEGylated liposomal doxorubicin nanodrugs. Biochimica et Biophysica Acta (BBA) - General Subjects [Internet]. 2021;1865 (5) :129849. Publisher's VersionAbstract

Background In Doxil®, PEGylated nanoliposomes are created by hydration of the lipids in ammonium sulfate, and are remotely loaded with doxorubicin by a transmembrane ammonium gradient. The ammonium sulfate is then removed from the external aqueous phase, surrounding the liposomes, and replaced by an isoosmotic sucrose solution in 10 mM histidine buffer at pH 6.5. Methods We prepared PEGylated liposomal doxorubicin (PLD) with a series of ammonium monovalent salts that after remote loading became the intraliposome doxorubicin counteranions. We analyzed the liposomes by solution X-ray scattering, differential scanning calorimetry, and electron micropscopy. Results PLDs prepared with sulfonic acid derivatives as counteranion exhibited chemical and physical stabilities. We determined the effect of these ammonium salt counteranions on the structure, morphology, and thermotropic behavior of the PEGylated nanoliposomes, formed before and after doxorubicin loading, and the bulk properties of the doxorubicin-counteranion complexes. By comparing the structure of the doxorubicin complexes in the bulk and inside the nanoliposomes, we revealed the effect of confinement on the structure and doxorubicin release rate for each of the derivatives of the ammonium sulfonic acid counteranions. Conclusions We found that the extent and direction of the doxorubicin confinement effect and its release rate were strongly dependent on the type of counteranion. The counteranions, however, neither affected the structure and thermotropic behavior of the liposome membrane, nor the thickness and density of the liposome PEG layers. In an additional study, it was demonstrated that PLD made with ammonium-methane sulfonate exhibit a much lower Hand and Foot syndrome. General significance The structure, physical state, and pharmacokinetics of doxorubicin in PEGylated nanoliposomes, prepared by transmembrane remote loading using gradients of ammonium salts, strongly depend on the counteranions.

2019
Shaltiel L, Shemesh A, Raviv U, Barenholz Y, Levi-Kalisman Y. Synthesis and Characterization of Thiolate-Protected Gold Nanoparticles of Controlled Diameter. J. Phys. Chem. C [Internet]. 2019;123 (46) :28486-28493. Publisher's Version
2016
Schilt Y, Berman T, Wei X, Barenholz Y, Raviv U. Using solution X-ray scattering to determine the high-resolution structure and morphology of PEGylated liposomal doxorubicin nanodrugs. Biochimica et Biophysica Acta (BBA)-General Subjects [Internet]. 2016;1860 (1) :108-119. Publisher's Version
2015
Turjeman K, Bavli Y, Kizelsztein P, Schilt Y, Allon N, Katzir TB, Sasson E, Raviv U, Ovadia H, Barenholz Y. Nano-drugs based on nano sterically stabilized liposomes for the treatment of inflammatory neurodegenerative diseases. PLoS One [Internet]. 2015;10 (7) :e0130442. Publisher's Version
2012
Zucker D, Andriyanov AV, Steiner A, Raviv U, Barenholz Y. Characterization of PEGylated nanoliposomes co-remotely loaded with topotecan and vincristine: relating structure and pharmacokinetics to therapeutic efficacy. Journal of controlled release [Internet]. 2012;160 (2) :281-289. Publisher's Version
2006
Safinya CR, Ewert K, Ahmad A, Evans HM, Raviv U, Needleman DJ, Lin AJ, Slack NL, George C, Samuel CE. Cationic liposome–DNA complexes: from liquid crystal science to gene delivery applications. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences [Internet]. 2006;364 (1847) :2573-2596. Publisher's Version
2005
Raviv U, Needleman DJ, Li Y, Miller HP, Wilson L, Safinya CR. Cationic liposome–microtubule complexes: Pathways to the formation of two-state lipid–protein nanotubes with open or closed ends. Proceedings of the National Academy of Sciences of the United States of America [Internet]. 2005;102 (32) :11167-11172. Publisher's Version