UV-induced gelation on nanometer scale using liposome reactor
UV-induced gelation on nanometer scale using liposome reactor
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DOI：
10.1021/ma011644
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发表时间：
2002-02-26
期刊：
影响因子：
5.5
通讯作者：
Levon, K
中科院分区：
文献类型：
--
作者：
Kazakov, S;Kaholek, M;Levon, K
提出了一种纳米尺度的高分子水凝胶球形颗粒（纳米凝胶）制备方法。该方案包括将水凝胶形成成分包封到脂质体中，脂质体内紫外线诱导聚合，用洗涤剂溶解脂质双分子层，通过透析去除磷脂、洗涤剂分子及其胶束，并通过温度梯度蒸发干燥纳米凝胶。采用动态光散射技术表征了聚丙烯酰胺、聚n -异丙基丙烯酰胺和聚n -异丙基丙烯酰胺-co-1-乙烯咪唑水凝胶颗粒的粒径分布。将n -十八烷基丙烯酰胺疏水链固定在聚（n -异丙基丙烯酰胺-co-1-乙烯咪唑）水凝胶颗粒表面，作为锚点将纳米凝胶附着在脂质双分子层上。制备的纳米凝胶的直径在30 ~ 300 nm之间。研究了脂质体、纳米凝胶及其混合物的溶剂、温度和pH敏感性，发现在混合后，磷脂双分子层总是包裹在非锚定和锚定水凝胶颗粒的表面。当凝胶颗粒坍塌时，观察到脂质双层包被纳米凝胶（脂珠）聚集。含有非锚定核的脂珠和含有锚定水凝胶核的脂珠的聚集机制不同。纳米尺寸的水凝胶-脂质体结构对于仿生感觉系统、控制释放装置和多价受体等应用具有潜在的重要性。
A protocol for preparation of polymer hydrogel spherical particles on a nanometer scale (nanogels) was developed. The protocol includes encapsulation of hydrogel-forming components into liposomes, UV-induced polymerization within the liposomes, solubilization of the lipid bilayer by detergent, removal of the phospholipid, detergent molecules, and their micelles by dialysis, and drying nanogels by evaporation in a temperature gradient. Dynamic light scattering technique was employed to characterize the size distribution of poly(acrylamide), poly(N-isopropylacrylamide), and poly(N-isopropylacrylamide-co-1-vinylimidazole) hydrogel particles. Hydrophobic chains of N-octadecylacrylamide were immobilized onto the surface of the poly(N-isopropylacrylamide-co-1-vinylimidazole) hydrogel particles to use them as anchors for attaching the nanogels onto the lipid bilayers. The diameter of the nanogels prepared varied between 30 and 300 nm. The solvent, temperature, and pH sensitivities of the liposomes, nanogels, and their mixtures were studied, It was found that the phospholipid bilayer always coats the surface of both unanchored and anchored hydrogel particles upon mixing. Aggregation of the lipid bilayer-coated nanogels (lipobeads) was observed when the gel particles collapsed. The mechanism of aggregation differs for the lipobeads containing unanchored cores and those containing anchored hydrogel cores. The hydrogel-liposome structures of a nanometer size are of potential importance for applications such as biomimetic sensory systems, controlled release devices, and multivalent receptors.