Preparation of pH-sensitive anionic liposomes designed for drug delivery system (DDS) application.
We prepared pH-sensitive anionic liposomes composed solely of anionic bilayer membrane components that were designed to promote efficient release of entrapped agents in response to acidic pH. The pH-sensitive anionic liposomes showed high dispersion stability at neutral pH, but the fluidity of the bilayer membrane was enhanced in an acidic environment. These liposomes were rather simple and were composed of dimyristoylphosphatidylcholine (DMPC), an anionic bilayer membrane component, and polyoxyethylene sorbitan monostearate (Tween 80). In particular, the present pH-sensitive anionic liposomes showed higher temporal stability than those of conventional DMPC/DPPC liposomes. We found that pHsensitive properties strongly depended on the molecular structure, pKa value, and amount of an incorporated anionic bilayer membrane component, such as sodium oleate (SO), dimyristoylphosphatidylserine (DMPS), or sodium β-sitosterol sulfate (SS). These results provide an opportunity to manipulate liposomal stability in a pH-dependent manner, which could lead to the formulation of a high performance drug delivery system (DDS).
Functional Materials Science Research Laboratories, R&D, Lion Corporation.
Asami
A
Aoki
Hikaru
H
Akaboshi
Taku
T
Ogura
Tatsuo
T
Aikawa
Takeshi
T
Kondo
Norio
N
Tobori
Makoto
M
Yuasa
D000838:Anions; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D016503:Drug Delivery Systems; D015195:Drug Design; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000138:chemical synthesis* / Q000737:chemistry; D008560:Membrane Fluidity; D015394:Molecular Structure; D019301:Oleic Acid / Q000737:chemistry; D010718:Phosphatidylserines / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry
D000838:Anions; D008081:Liposomes; D010718:Phosphatidylserines; D011136:Polysorbates; D019301:Oleic Acid; C013173:osteum; C042859:dimyristoylphosphatidylserine; D004134:Dimyristoylphosphatidylcholine