Two-dimensional polymerization of lipid bilayers: Visible-light-sensitized photoinitiation
Two-dimensional polymerization of lipid bilayers: Visible-light-sensitized photoinitiation
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DOI：
10.1021/ma960935t
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发表时间：
1997-01-13
期刊：
影响因子：
5.5
通讯作者：
OBrien, DF
中科院分区：
文献类型：
--
作者：
Clapp, PJ;Armitage, BA;OBrien, DF
报道了通过膜结合花青染料的可见光照射合成脂质双层的敏化聚合。可见光引发的聚合反应成功，脂质体单独或部分由 1-棕榈酰基-2-[10-(2',4'-己二烯酰氧基)癸酰基]-sn-甘油-3-磷脂酰胆碱 (mono-SorbPC)、 1,2-双[10-(2',4'-己二烯酰氧基)癸酰基]-sn-甘油-3-磷脂酰胆碱(bis-SorbPC)或1,2-双(2,4-十八碳二烯酰基)-sn-甘油-3-磷脂酰胆碱(DenPC)。这里报道的镇流敏化染料可以方便地掺入脂质体中。许多此类研究中都使用了增感染料 N,N'-双十八烷基-3,3,3',3'-四甲基吲哚羰花青高氯酸盐 DiIC(18)3，因为其吸收特性与光源的光谱输出特别匹配。对来自 mono-SorbPC 敏化光转化的脂质产物进行酯交换，并通过尺寸排阻色谱进行分析，结果表明存在相对数均聚合度为 10(2) 的聚合物。该值与 AIBN 引发的单 SorbPC 脂质体聚合的值相似。敏化聚合过程依赖于氧气的存在，自旋捕获实验证明了超氧阴离子的形成。 pH、光强度和温度的单独影响表明，聚合过程是由电子从染料激发态转移到氧引发的，产生超氧阴离子，超氧阴离子在水介质中结合形成过氧化氢。此外，还表明单体脂质可以通过在实验温度下添加过氧化氢来聚合。这些数据表明染料敏化聚合是通过紧邻脂质双层的羟基自由基的形成介导的。这种聚合化学似乎可能与氧依赖系统（例如活组织）兼容。
The sensitized polymerization of synthetic lipid bilayers via visible-light irradiation of membrane-bound cyanine dyes is reported. Visible-light-initiated polymerizations were successful with liposomes composed solely or partly of either 1-palmitoyl-2-[10-(2',4'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphatidylcholine (mono-SorbPC), 1,2-bis[10-(2',4'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphatidylcholine (bis-SorbPC), or 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-phosphatidylcholine (DenPC). The ballasted sensitizing dyes reported here were conveniently incorporated into liposomes. The sensitizing dye N,N'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate, DiIC(18)3, was used in many of these studies because its absorption properties were especially well matched to the spectral output of the light source. The lipid product from the sensitized photoconversion of mono-SorbPC was transesterified and analyzed by size exclusion chromatography, which revealed the presence of a polymer with a relative number-average degree of polymerization of 10(2). This value is similar to those reported for the AIBN-initiated polymerization of mono-SorbPC liposomes. The sensitized polymerization process is dependent on the presence of oxygen, and spin-trapping experiments demonstrated the formation of superoxide anion. The indivdual effects of pH, light intensity, and temperature suggest that the polymerization process is initiated by electron transfer from the dye excited state to oxygen, to yield superoxide anion, which in aqueous media combines to form hydrogen peroxide. In addition, it was shown that the monomeric lipids could be polymerized by addition of hydrogen peroxide at the experimental temperatures. These data suggest that the dye-sensitized polymerization is mediated by the formation of hydroxyl radicals in the immediate vicinity of the lipid bilayer. This polymerization chemistry appears likely to be compatible with oxygen-dependent systems such as living tissues.