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Hydroxyethyl acrylate‐based copolymer‐immobilized liposomes as UV and thermo dual‐triggerable carriers
Author(s) -
Kim JinChul
Publication year - 2015
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201400254
Subject(s) - liposome , lower critical solution temperature , acrylate , copolymer , nuclear chemistry , chemistry , materials science , polymer chemistry , chromatography , polymer , organic chemistry , biochemistry
UV‐ and temperature‐triggerable liposomes were prepared by modifying the surface of egg phosphatidylcholine (EPC) liposomes with poly(hydroxyethyl acrylate–co‐coumaryl acrylate–co‐2‐ethylhexyl acrylate) (P(HEA–CA–EHA)). P(HEA–CA–EHA)s were prepared by a free radical polymerization using reaction mixtures where HEA/CA/EHA molar ratio was 97.5:0.5:2 and 97:1:2. The CA residue of P(HEA–CA–EHA) (97.5:0.5:2) and that of P(HEA–CA–EHA) (97:1:2) were readily dimerized under the irradiation of UV light (254 nm, 6 W). P(HEA–CA–EHA) (97:1:2) exhibited a lower critical solution temperature (LCST) around 37°C but P(HEA–CA–EHA) (97.5:0.5:2) showed no LCST. EPC liposomes incorporating the copolymers of which EPC/copolymer ratio was 200:1–10:1 were prepared by bath‐type sonication. The fluorescence quenching degree was 65–92%, depending on the EPC/copolymer ratio. The liposomes released their content in response to the irradiation of the UV light, and the photo‐sensitivity of liposomes incorporating P(HEA–CA–EHA) (97:1:2) was somewhat higher than that of liposomes incorporating P(HEA–CA–EHA) (97.5:0.5:2). Liposomes incorporating P(HEA–CA–EHA) (97:1:2) exhibited a temperature‐responsive release, but liposomes bearing P(HEA–CA–EHA) (97.5:0.5:2) did not. The UV‐ and temperature‐triggered release property of the liposomes was possibly due to the photo‐ and thermo‐sensitive property of the copolymer immobilized on the liposomal surface. Practical applications: The liposomes incorporating P(HEA‐CA‐EHA) could be applied in controlled release drug delivery, releasing the cargo in response to ultra‐violet light irradiation and to temperature change. UV (panel A) and thermo (panel B)‐triggered release from liposome incorporating P(HEA–CA–EHA). EPC to copolymer ratio was 1:0 (●), 200:1 (○), 100:1 (▾), 50:1 (Δ), 20:1 (▪), and 10:1 (□) in panel (A). Temperature of release medium was 25°C (○), 36°C (Δ), and 44°C (●) in panel (B).