title: Photoisomerisable cholesterol derivatives as photo-trigger of liposomes: effect of lipid polarity, temperature, incorporation ratio, and cholesterol.
abstract: Three cholesterol derivatives containing an azobenzene moiety with different polarities were designed and synthesized (AB lipids 1 to 3). The effects of structure, temperature and incorporation ratio on liposomes were studied, with the results showing that the polarity in 4-substituent and in some cases, 4'-substituent may be important for their incorporation feasibility and photoisomerizability in liposomes. Liposomes incorporated with AB lipid 3 could release multi-pulsatilely upon UV and visible light irradiation both in gel state and liquid crystal state of liposomes. An increase in the incorporation ratio of AB lipid 3 enhanced the amount of drug released greatly. Unlike other azobenzene photo-triggers reported, AB lipid 3 did not increase the spontaneous release of liposomes. Furthermore, cholesterol suppressed the spontaneous release of liposomes.
authors.affiliation: Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
authors.forename: Xin-Ming
authors.initials: XM
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Yu-Lu
authors.initials: YL
authors.lastname: Wang
authors.forename: Jin-Ye
authors.initials: JY
authors.lastname: Wang
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002784:Cholesterol / Q000031:analogs & derivatives*; D007536:Isomerism; D008027:Light; D008081:Liposomes / Q000737:chemistry* / Q000528:radiation effects; D010777:Photochemistry; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D001391:Azo Compounds; D008081:Liposomes; D002784:Cholesterol; C009850:azobenzene