Department of Chemistry, University of Toronto, Mississauga, Ontario, Canada.
Biomacromolecules. 2011 Jun 13;12(6):2364-74. doi: 10.1021/bm200266z. Epub 2011 Jun 3.
We have fabricated Lipogels consisting of a single POPC lipid bilayer supported by a micrometer-sized, thermoresponsive, hydrophobically modified (HM), hydrogel sphere. The hydrogel consists of a lightly cross-linked poly(N-isopropylacrylamide) (pNIPAM) core surrounded by a highly cross-linked acrylic acid (AA)-rich p(NIPAM-co-AA) shell. The lipid bilayer was assembled by binding liposomes to HM microgels, followed by several cycles of freeze-thaw. The pNIPAM volume phase transition (VPT) at ∼32 °C was present both before and after hydrophobic modification and after lipid bilayer coating. Fluorescence studies confirmed the fusion of liposomes into a continuous single bilayer. At a temperature above the VPT, it was found that the volume decrease in the hydrogel was coupled to the appearance of highly curved obtrusions of the uncompromised lipid bilayer into the surroundings. It is anticipated that these properties of Lipogels will prove to be useful in drug delivery applications and in fundamental biophysical studies of membranes.
我们制备了由单个 POPC 脂质双层组成的脂质凝胶，该脂质双层由微米级的热响应性、疏水改性 (HM)、水凝胶球支撑。水凝胶由轻度交联的聚 N-异丙基丙烯酰胺 (pNIPAM) 核和富含丙烯酸 (AA) 的高度交联的 p(NIPAM-co-AA) 壳组成。脂质双层是通过将脂质体结合到 HM 微凝胶上，然后进行几次冻融循环组装而成的。在疏水改性前后以及脂质双层涂覆后，均存在 pNIPAM 体积相转变 (VPT) 在 ∼32 °C。荧光研究证实了脂质体融合成连续的单层。在高于 VPT 的温度下，发现水凝胶的体积减小与未妥协的脂质双层向周围形成高度弯曲的突起同时出现。预计脂质凝胶的这些特性将在药物输送应用和膜的基础生物物理研究中证明是有用的。
