School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST Road, Ulsan 689-798, Korea.
J Am Chem Soc. 2012 Mar 7;134(9):4030-3. doi: 10.1021/ja211728x. Epub 2012 Feb 22.
We synthesized a boroxole-containing styrenic monomer that can be polymerized by the reversible addition-fragmentation and chain transfer (RAFT) method. Poly(styreneboroxole) (PBOx) and its block copolymers with a poly(ethylene glycol) (PEG) as a hydrophilic block displayed binding to monosaccharides in phosphate buffer at neutral pH, as quantified by Wang's competitive binding experiments. By virtue of a controlled radical polymerization, we were able to adjust the degree of polymerization of the PBOx block to yield sugar-responsive block copolymers that self-assembled into a variety of nanostructures including spherical and cylindrical micelles and polymer vesicles (polymersomes). Polymersomes of these block copolymers exhibited monosaccharide-responsive disassembly in a neutral-pH medium. We demonstrated the possibility of using these polymersomes as sugar-responsive delivery vehicles for insulin in neutral phosphate buffer (pH 7.4). Encapsulated insulin could be released from the polymersomes only in the presence of sugars under physiologically relevant pH conditions.
我们合成了一种含硼氧杂环的苯乙烯单体，可通过可逆加成-断裂链转移（RAFT）方法聚合。聚（苯乙烯硼酸酯）（PBOx）及其与聚乙二醇（PEG）作为亲水性嵌段的嵌段共聚物在中性 pH 的磷酸盐缓冲液中显示出与单糖的结合，这通过 Wang 的竞争结合实验进行了定量。通过受控自由基聚合，我们能够调整 PBOx 嵌段的聚合度，以得到对糖有响应的嵌段共聚物，这些嵌段共聚物自组装成各种纳米结构，包括球形和圆柱形胶束以及聚合物囊泡（聚合物囊泡）。这些嵌段共聚物的聚合物囊泡在中性 pH 介质中表现出对单糖的响应性解组装。我们证明了这些聚合物囊泡作为胰岛素在中性磷酸盐缓冲液（pH 7.4）中响应性递送载体的可能性。在生理相关的 pH 条件下，只有在存在糖的情况下，囊泡内的胰岛素才能被释放出来。
