Fabrication of Surface-Modified Hydrogels with Polyion Complex for Controlled Release
Fabrication of Surface-Modified Hydrogels with Polyion Complex for Controlled Release
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DOI：
10.1021/cm1002302
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发表时间：
2010-05-11
影响因子：
8.6
通讯作者：
Akashi, Mitsuru
中科院分区：
文献类型：
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作者：
Takemoto, Yukie;Ajiro, Hiroharu;Akashi, Mitsuru
为了在不改变水凝胶体积的情况下控制药物分子的释放，制备了由聚乙烯胺(PVAm)和聚丙烯酸(PAAc)组成的多离子络合物表面修饰水凝胶。我们首先制备了poly(N-vinylacetamide)-co-poly(N-vinylformamide)(聚(NVA-co-NVF))水凝胶，然后通过水解反应在水凝胶表面生成了一层阳离子的PVAm层。将AAc聚合成表面阳离子水凝胶，得到了一种只在表面含有PVAm和PAAc多离子络合物(PIC)的水凝胶。这种表面-PIC水凝胶(SPIC凝胶)可以在中性pH条件下抑制模型药物(异硫氰酸荧光素标记的葡聚糖，M-w=9500)的释放，因为PIC表层致密，并根据PIC的形成和解离在pH条件下反复控制药物释放。由于PIC层足够薄，以保持水凝胶的原始尺寸，因此实现了控制释放，而没有很大的体积变化。此外，与PIC凝胶相比，SPIC凝胶保留了更多的模型药物，PIC凝胶从表面到内部都具有多离子络合物。因此，含有PIC的表面修饰水凝胶，即SPIC凝胶，可用于需要恒定体积和大载药量的受控给药系统。
Surface-modified hydrogels with a polyion complex composed of poly(vinylamine) (PVAm) and poly(acrylic acid) (PAAc) were prepared in order to control the release of drug molecules without a volume change of the hydrogel. We first prepared a poly(N-vinylacetamide)-co-poly(N-vinylformamide) (poly(NVA-co-NVF)) hydrogel, and then used a hydrolysis reaction to produce a cationic PVAm layer on the surface of the hydrogel. The polymerization of AAc to the surface-cationized hydrogel resulted in a hydrogel that possesses a polyion complex (PIC) of PVAm and PAAc only on the surface. This surface-PIC hydrogel (sPIC gel) could suppress the release of a model drug (Fluorescein isothiocyanate labeled Dextran, M-w = 9500) under neutral pH conditions because of the tight PIC surface layer, and repeatedly controlled the drug release against the pH conditions depending on the formation and dissociation of PIC. Controlled release was achieved without a large volume change, because the PIC layer was thin enough to maintain the original size of the hydrogel. Furthermore, the sPIC gel retained a larger amount of model drug as compared to the PIC gel, which possesses the polyion complex from the surface to the inside of the hydrogel. Consequently, the surface-modified hydrogel with PIC, that is sPIC gel, is useful for controlled drug delivery systems that require a constant volume and large drug loading.