Kocik M K, Mykhaylyk O O, Armes S P
Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, Yorkshire S3 7HF, UK.
Soft Matter. 2014 Jun 14;10(22):3984-92. doi: 10.1039/c4sm00415a. Epub 2014 Apr 14.
Worm-like diblock copolymer nanoparticles comprising poly(glycerol monomethacrylate) (PGMA) as a stabilizer block and poly(2-hydroxypropyl methacrylate) (PHPMA) as a core-forming block were readily synthesized at 10% w/w solids via aqueous dispersion polymerization at 70 °C using Reversible Addition-Fragmentation chain Transfer (RAFT) chemistry. On cooling to 20 °C, soft transparent free-standing gels are formed due to multiple inter-worm interactions. These aqueous PGMA-PHPMA diblock copolymer worms were freeze-dried, then redispersed in water with cooling to 3-5 °C before warming up to 20 °C; this protocol ensures molecular dissolution of the copolymer chains, which aids formation of a transparent aqueous gel. Rheology, SAXS and TEM studies confirm that such reconstituted gels comprise formed PGMA-PHPMA copolymer worms and they possess essentially the same physical properties determined for the original worm gels prior to freeze-drying. Such worm gel reconstitution is expected to be highly beneficial in the context of various biomedical applications, since it enables worm gels to be readily prepared using a wide range of cell growth media as the continuous aqueous phase.
以聚（甲基丙烯酸甘油酯）（PGMA）为稳定嵌段、聚（甲基丙烯酸2-羟丙酯）（PHPMA）为成核嵌段的蠕虫状二嵌段共聚物纳米粒子，通过可逆加成-断裂链转移（RAFT）化学法，在70℃下以10% w/w的固含量通过水分散聚合反应轻松合成。冷却至20℃时，由于蠕虫间的多重相互作用形成了柔软透明的自立凝胶。这些水性PGMA-PHPMA二嵌段共聚物蠕虫经冷冻干燥，然后在冷却至3-5℃后再分散于水中，最后升温至20℃；该方案确保了共聚物链的分子溶解，有助于形成透明的水性凝胶。流变学、小角X射线散射（SAXS）和透射电子显微镜（TEM）研究证实，这种重构凝胶包含已形成的PGMA-PHPMA共聚物蠕虫，并且它们具有与冷冻干燥前原始蠕虫凝胶基本相同的物理性质。这种蠕虫凝胶重构在各种生物医学应用中预计将非常有益，因为它能够使用多种细胞生长培养基作为连续水相轻松制备蠕虫凝胶。
