Zayas-Gonzalez Yashira M, Ortiz Benjamín J, Lynn David M
Department of Chemical and Biological Engineering, University of Wisconsin-Madison , 1415 Engineering Drive, Madison, Wisconsin 53706, United States.
Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
Biomacromolecules. 2017 May 8;18(5):1499-1508. doi: 10.1021/acs.biomac.7b00043. Epub 2017 Apr 14.
We report the reactive layer-by-layer assembly of amine-reactive polymer multilayers using an azlactone-functionalized polymer and small-molecule diamine linkers. This approach yields cross-linked polymer/linker-type films that can be further functionalized, after fabrication, by treatment with functional primary amines, and provides opportunities to incorporate other useful functionality that can be difficult to introduce using other polyamine building blocks. Films fabricated using poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and three model nondegradable aliphatic diamine linkers yielded reactive thin films that were stable upon incubation in physiologically relevant media. By contrast, films fabricated using PVDMA and varying amounts of the model disulfide-containing diamine linker cystamine were stable in normal physiological media, but were unstable and eroded rapidly upon exposure to chemical reducing agents. We demonstrate that this approach can be used to fabricate functionalized polymer microcapsules that degrade in reducing environments, and that rates of erosion, extents of capsule swelling, and capsule degradation can be tuned by control over the relative concentration of cystamine linker used during fabrication. The polymer/linker approach used here expands the range of properties and functions that can be designed into reactive PVDMA-based coatings, including functionality that can degrade, erode, and undergo triggered destruction in aqueous environments. We therefore anticipate that these approaches will be useful for the functionalization, patterning, and customization of coatings, membranes, capsules, and interfaces of potential utility in biotechnical or biomedical contexts and other areas where degradation and transience are desired. The proof of concept strategies reported here are likely to be general, and should prove useful for the design of amine-reactive coatings containing other functional structures by judicious control of the structures of the linkers used during assembly.
我们报道了使用氮杂内酯功能化聚合物和小分子二胺连接剂进行胺反应性聚合物多层膜的反应性逐层组装。这种方法产生了交联的聚合物/连接剂型薄膜，在制备后可以通过用功能性伯胺处理进一步功能化，并提供了纳入其他有用功能的机会，而使用其他多胺构建块可能难以引入这些功能。使用聚（2-乙烯基-4,4-二甲基氮杂内酯）（PVDMA）和三种模型不可降解脂肪族二胺连接剂制备的薄膜产生了反应性薄膜，这些薄膜在生理相关介质中孵育时是稳定的。相比之下，使用PVDMA和不同量的含二硫键模型二胺连接剂胱胺制备的薄膜在正常生理介质中是稳定的，但在暴露于化学还原剂时不稳定并迅速侵蚀。我们证明，这种方法可用于制备在还原环境中降解的功能化聚合物微胶囊，并且可以通过控制制备过程中使用的胱胺连接剂的相对浓度来调节侵蚀速率、胶囊溶胀程度和胶囊降解程度。这里使用的聚合物/连接剂方法扩展了可以设计到基于反应性PVDMA的涂层中的性能和功能范围，包括在水性环境中可以降解、侵蚀和发生触发破坏的功能。因此，我们预计这些方法将有助于在生物技术或生物医学背景以及其他需要降解和短暂性的领域中对涂层、膜、胶囊和界面进行功能化、图案化和定制。这里报道的概念验证策略可能具有普遍性，并且通过明智地控制组装过程中使用的连接剂的结构，应该对设计包含其他功能结构的胺反应性涂层有用。
