Frisch Hendrik, Besenius Pol
Organic Chemistry Institute and CeNTech, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, D-48149, Münster, Germany.
Macromol Rapid Commun. 2015 Feb;36(4):346-63. doi: 10.1002/marc.201400623. Epub 2014 Dec 22.
Self-assembled materials, which are able to respond to external stimuli, have been extensively studied over the last decades. A particularly exciting stimulus for a wide range of biomedical applications is the pH value of aqueous solutions, since deprotonation-protonation events are crucial for structural and functional properties of biopolymers. In living cells and tissues, intra- and extracellular pH values are stringently regulated, but can deviate from pH neutral as observed for example in tumorous, inflammatory sites, in endocytic pathways, and specific cellular compartments. By using a pH-switch as a stimulus, it is thereby possible to address specific targets in order to cause a programmed response of the supramolecular material. This strategy has not only been successfully applied in fundamental research but also in clinical studies. In this feature article, current strategies that have been used in order to design materials with pH-responsive properties are illustrated. This discussion only addresses selected examples from the last four years, the self-assembly of polymer-based building blocks, assemblies emerging from small molecules including surfactants or derived from biological macromolecules, and finally the controlled self-assembly of oligopeptides.
在过去几十年里，能够响应外部刺激的自组装材料得到了广泛研究。对于广泛的生物医学应用而言，一个特别令人兴奋的刺激因素是水溶液的pH值，因为去质子化-质子化事件对于生物聚合物的结构和功能特性至关重要。在活细胞和组织中，细胞内和细胞外的pH值受到严格调控，但可能会偏离pH中性，例如在肿瘤、炎症部位、内吞途径和特定细胞区室中观察到的情况。通过使用pH开关作为刺激因素，从而有可能靶向特定目标，以引发超分子材料的程序化响应。这种策略不仅已成功应用于基础研究，也应用于临床研究。在这篇专题文章中，阐述了目前用于设计具有pH响应特性材料的策略。本讨论仅涉及过去四年中的部分实例，包括基于聚合物的构建块的自组装、由小分子（包括表面活性剂）或生物大分子衍生而来的组装体，以及最后寡肽的可控自组装。
