Hydrogen-Bonded Hybrid Multilayers: Film Architecture Controls Release of Macromolecules
Hydrogen-Bonded Hybrid Multilayers: Film Architecture Controls Release of Macromolecules
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DOI：
10.1021/ma8013564
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发表时间：
2008-11-25
期刊：
影响因子：
5.5
通讯作者：
Sukhishvili, Svetlana A.
中科院分区：
文献类型：
--
作者：
Erel-Unal, Irem;Sukhishvili, Svetlana A.
我们报告了纯氢键杂化聚合物多层膜的构造，该多层膜由具有低和高 pH 稳定性的聚合物对组成，并表明膜解构的临界 pH 值、释放的组分分数和膜溶解速率可以通过改变膜成分和结构在 3 至 9.5 的宽 pH 范围内调节。薄膜构件是聚（N-乙烯基己内酰胺）（PVCL）/聚（L-天冬氨酸）（PLAA）双层作为氢键聚合物对，具有低pH稳定性（临界崩解pH值类似于3.3），以及聚（N-乙烯基己内酰胺）（PVCL）/单宁酸（TA）双层作为氢键聚合物，具有更高的临界崩解pH值，类似于9.5。使用逐层技术在低 pH 条件下制备混合 TA/PVCL/PLAA 多层材料。薄膜沉积和 pH 诱导解构之后，进行衰减全反射模式 (ATR-FTIR) 下的原位傅里叶变换红外光谱和相位调制椭圆光度术。 PVCL/TA 和 PVCL/PLAA 对以交替或堆叠方式沉积。具有不同层排列的薄膜具有截然不同的 pH 溶解曲线。在所有情况下，PVCL/TA 层的存在都会将 PLAA 从薄膜中释放的 pH 值改变为更碱性的值。在具有堆叠结构的薄膜中[(PVCL/PLAA)(6) (PVCL/TA)(n)]，薄膜破坏模式取决于连续沉积的PVCL/PLAA对的数量和表面堆叠中PVCL/TA层对的数量。对于底部堆叠中由六个 PVCL/PLAA 双层组成的薄膜，薄膜崩解和 PLAA 释放的临界 pH 值随顶部厚度 (PVCL/TA) 的变化而变化，堆叠的 pH 范围为 3.5 至 5，n 范围为 0 至 12。在混合交替薄膜中，[(PVCL/TA)(1) (PVCL/PLAA)(1)](n) (1:1)，PLAA 和 TA 的释放更多相互依存。 PVCL/TA 对的接近进一步延迟了 PLAA 的释放直至接近中性 pH 值。此外，通过薄膜扩散的 PLAA 链引发了 PVCL/TA 相互作用的破坏，导致释放出大约 15-20% 的 TA。这些结果证明了 pH 稳定性差异很大的氢键聚合物对的接近和混合对薄膜分解模式的影响。释放活性分子和/或聚合物的可能性与薄膜成分的生物相容性相结合，使得此类系统成为未来生物医学应用的有吸引力的候选者。
We report on the construction of purely hydrogen-bonded hybrid polymer multilayers, which are composed of polymer pairs with low- and high- pH stability, and show that the critical pH value of film deconstruction, fraction of components released, and the rate of film dissolution can be tuned in a wide pH range from 3 to 9.5 by varying film composition and architecture. The film building blocks were poly(N-vinylcaprolactam) (PVCL)/poly(L-aspartic acid) (PLAA) bilayers as pairs of hydrogen-bonded polymers with low pH stability (critical disintegration pH of similar to 3.3), and poly(N-vinylcaprolactam) (PVCL)/tannic acid (TA) bilayers as hydrogen-bonded polymers with a higher critical disintegration pH of similar to 9.5. Hybrid TA/PVCL/PLAA multilayers were prepared at low pH using a layer-by-layer technique. Film deposition and pH-induced deconstruction were followed by in situ Fourier transform infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and phase-modulated ellipsometry. PVCL/TA and PVCL/PLAA pairs were deposited in either alternating or stacked manner. Films with various layer arrangements had drastically different pH dissolution profiles. In all cases, the presence of PVCL/TA layers shifted pH values for release of PLAA from the film to more basic values. In the films with stacked architecture [(PVCL/PLAA)(6) (PVCL/TA)(n)], the mode of film destruction was dependent on both the amount of consecutively deposited PVCL/PLAA pairs and the number of PVCL/TA layer pairs in the surface stack. For the films composed of six bilayers of PVCL/PLAA in the base stack, the critical pH for film disintegration and PLAA release varied with the thickness of the top (PVCL/TA),, stack in a range from pH 3.5 to 5 with n ranging from 0 to 12. In hybrid alternating films, [(PVCL/TA)(1) (PVCL/PLAA)(1)](n) (1:1), release of PLAA and TA was more interdependent. The proximity of PVCL/TA pairs has further delayed PLAA release up to near-neutral pH. In addition, PLAA chains diffusing through the film triggered disruption of PVCL/TA interactions resulting in release of similar to 15-20% of TA. These results demonstrate the effects of proximity and intermixing of hydrogen-bonded polymer pairs of greatly different pH stability on film decomposition modes. The possibility of releasing active molecules and/or polymers combined with the biocompatibility of film components makes such systems attractive candidates for future biomedical applications.