A new sensor for bacteria using binding or specific degradation of stimuli responsive polymers

该项目将研究使用智能聚合物检测细菌。这项工作的基本原理是，超支化聚合物的链端的结合可用于将聚合物附着到细菌的细胞表面。在某些情况下，这种结合可以使聚合物通过关键的构象变化，其中聚合物在水溶液中从开放的溶剂化卷曲变为紧密的非溶剂化小球。在其他情况下，构象变化可以在结合后通过小的温度变化而引起。此外，可以使用链端配体的仔细设计来确保结合可以被配制为对不同细菌物种上的各个位点特异性。从开放式螺旋到紧密小球的变化可以通过监测位于聚合物链上的化学标记的荧光来检测。这些标记通过荧光的变化报告链的构象。该项目将研究两种可溶性聚合物的使用，这些聚合物可以添加到伤口床上作为检测细菌存在的方法，也可以固定水凝胶材料。后者可用作活性伤口敷料。在该技术的另一个版本中，超支化聚合物将被合成为具有可以被特定的细胞外蛋白酶降解的肽链末端。在这种情况下，聚合物将在端基降解后检测细菌，这将暴露极性羧基端基。因此，这些系统将在靶细菌的存在下从紧密的非溶剂化小球发展为开放的溶剂化链。简而言之，我们建议开发新的聚合物技术，以快速检测具有容易观察到的光学信号的细菌。

The project will investigate the use of a smart polymer for the detection of bacteria. The underlying principle of this work is that the binding of the chain ends of the hyperbranched polymers can be used to attach the polymer to the cell surface of bacteria. In some cases this binding can progress the polymer through a critical conformational change, in which the polymer changes, in aqueous soloution, from an open solvated coil to a tight non-solvated globule. In other instances the conformational change can be brought about after binding by a small temperature change. Furthermore, careful design of the chain-end ligand can be used to ensure that binding can be formulated to be specific to individual sites on different species of bacteria,. The change from open coil to tight globule can be detected by monitoring fluoresence from chemical labels situated on the polymer chain . These labels report on the chain's conformation by a change in fluoresence. The project will investigate the use of both soluble polymers, which could be added to a wound bed as a method of detecting the presence of bacteria and also immobilized hydrogel materials. The latter might be used as active wound dressings. In another version of this technology hyperbranched polymers will be synthesized to have peptide chain ends that can be degraded by specific extracelluar proteases. In this instance, the polymers will detect the bacteria following degradation of the end groups, which will expose polar carboxylic end groups. Thus, these systems will progress from a tight non-solvated globule to an open solvated chain in the presence of the target bacteria. In brief, we propose to develop novel polymer technology to rapidly detect bacteria with an easily observed optical signal.