Poly(methacrylic acid) hydrogel films and capsules: Response to pH and ionic strength, and encapsulation of macromolecules
Poly(methacrylic acid) hydrogel films and capsules: Response to pH and ionic strength, and encapsulation of macromolecules
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DOI：
10.1021/cm0517364
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发表时间：
2006-01-24
影响因子：
8.6
通讯作者：
Sukhishvili, SA
中科院分区：
文献类型：
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作者：
Kozlovskaya, V;Kharlampieva, E;Sukhishvili, SA
中性聚合物（聚（N-乙烯基吡咯烷酮），PVPON）与聚（甲基丙烯酸）（PMAA）的氢键多层膜被用作模板，使用碳二亚胺化学和乙二胺作为交联剂引入PMAA层之间的交联。在暴露于高pH时，PVPON完全从水凝胶基质中释放，产生表面附着的PMAA水凝胶。当这样的水凝胶沉积在二氧化硅颗粒的表面上，并且随后溶解颗粒核时，产生中空的单组分水凝胶胶囊。PMAA水凝胶膜和中空胶囊响应于溶液pH和/或离子强度的变化而经历可逆的、大的（2或3倍）尺寸变化。通过用静电缔合聚阳离子聚-N-乙基-4-乙烯基溴化吡啶（QPVP）“锁定”胶囊壁，胶囊用于捕获和储存大分子，例如500 kDa FITC-葡聚糖。当QPVP从胶囊壁解离时，在高盐浓度（0.6 M NaCl）下实现封装的大分子的释放。这些PMAA水凝胶胶囊的pH和盐响应以及聚阳离子控制的大分子包封有望在生物医学和生物技术中应用。
Hydrogen-bonded multilayers of a neutral polymer (poly(N-vinylpyrrolidone), PVPON) with poly(methacrylic acid) (PMAA) were used as templates to introduce cross-links between PMAA layers using carbodiimide chemistry and ethylenediamine as a cross-linking agent. Upon exposure to high pH, PVPON is completely released from the hydrogel matrix, producing surface-attached PMAA hydrogels. When such hydrogels are deposited at the surface of silica particles, and the particle core is subsequently dissolved, hollow one-component hydrogel capsules are produced. PMAA hydrogel films and hollow capsules underwent reversible, large (factors of 2 or 3) changes in size in response to changes in solution pH and/or ionic strength. The capsules were used for entrapment and storage of macromolecules such as 500 kDa FITC-dextran by "locking" the capsule wall with an electrostatically associating polycation, poly-N-ethyl-4-vinylpyridinium bromide (QPVP). The release of the encapsulated macromolecules was achieved under high salt concentrations (0.6 M NaCl) when QPVP dissociated from the capsule wall. The pH and salt response of these PMAA hydrogel capsules and the polycation-controlled encapsulation of macromolecules hold promise for applications in biomedicine and biotechnology.