Chemically Diverse Stimuli-Responsive Polymers for Myriad Applications

我们小组的研究计划旨在通过开发新型先进功能材料来解决人类健康和环境问题。我们解决这些问题的方法是使用刺激响应聚合物（SRP），该聚合物能够“感知”周围环境的变化并以特定的方式做出响应。最著名的 SRP 是聚（N-异丙基丙烯酰胺）（pNIPAm），它具有热响应性，即在 T>32 ℃/T<32 ℃ 的水中分别收缩/膨胀。可以生成具有宏观/微米/纳米尺度尺寸（分别为水凝胶、微米凝胶、纳米凝胶）的基于 pNIPAm 的交联水凝胶网络，并且还表现出热响应性。该提案描述了基于 pNIPAm 的 SRP 的使用及其化学的多样化，从而可以实现新的增值行为和特性。我们设想在三个主要研究主题中利用这些化学上多样化的 SRP 以及随之而来的多样化响应：1）传感和生物传感； 2）受控和触发的药物输送； 3) 人造肌肉/执行器。主题 1 的主要目标是通过生成具有各种化学成分的基于 pNIPAm 的微凝胶库来生成传感和生物传感的新范例，从而实现不同的响应并开发传感器。这个概念依赖于该小组已经开发的基于微凝胶的传感器（标准具），但是添加具有如此不同响应度的微凝胶将导致我们可以检测到的分析物的巨大多样性，我们将在阵列中使用这些分析物，并与模式识别/机器学习相结合来制造适用于任何事物的传感器。我们的第一个目标分析物是天然水中的磷酸盐；天然水域中的高磷酸盐浓度会导致藻类大量繁殖和大量鱼类死亡。通过持续监测磷酸盐浓度，可以在有利于藻类大量繁殖的条件成为问题之前予以解决。我们还将探索利用双层膜和抗菌肽的各种新传感方案。主题 2 将重点开发具有广泛触发器和释放动力学/曲线的受控/触发药物输送装置。我们将探索在标准具上使用化学上不同的硫醇来控制释放速率，结合微凝胶化学的定制，以产生释放曲线具有令人难以置信的多样性的释放装置。我们还将为该小组开展一项新的研究工作，通过生成能够触发巨噬细胞极化来治疗新疾病的微凝胶。主题 3 将重点关注生成能够触发驱动和运动的材料。这些技术将利用 SRP 以及形状记忆金属合金来实现此类行为。除了这些明确的主题之外，我的团队将始终致力于发现新材料以及材料的新应用，以创造更好的环境并改善人类健康。

Our group's research program is aimed at solving human health and environmental problems via the development of new advanced functional materials. Our approach to tackling these issues is via the use of stimuli-responsive polymers (SRPs) capable of "sensing" changes in their surroundings and responding in a specified way. The most well-known SRP is poly (N-isopropylacrylamide) (pNIPAm), that exhibits thermoresponsivity, i.e., it shrinks/swells in water at T>32 ºC/T<32 ºC, respectively. Crosslinked pNIPAm-based hydrogel networks with macro/micro/nano scale dimensions (hydrogels, microgels, nanogels, respectively) can be generated and also exhibit thermoresponsivity. This proposal describes the use of pNIPAm-based SRPs, and the diversification of their chemistry, such that new, value added behaviors and properties can be achieved. We envision utilizing these chemically diverse SRPs, and the concomitant diverse responsivities in three main research themes: 1) Sensing and biosensing; 2) Controlled and triggered drug delivery; and 3) Artificial muscles/actuators. The primary goal of Theme 1 is to generate new paradigms for sensing and biosensing by generating a library of pNIPAm-based microgels with various chemistry, such that diverse responsivities can be achieved and sensors developed. The concept relies on microgel-based sensors (etalons) that the group has already developed, but the addition of microgels with such diverse responsivities will lead to great diversity in analytes that we can detect, that we will use in arrays, combined with pattern recognition/machine learning to make sensors for anything. Our first target analyte will be phosphate in natural waters; high phosphate concentrations in natural waters lead to algae blooms and mass fish kills. By continuously monitoring phosphate concentration, conditions that favor algae blooms can be addressed before they become an issue. We will also explore a variety of new sensing schemes utilizing bilayer membranes and antimicrobial peptides. Theme 2 will focus on developing controlled/triggered drug delivery devices with a broad range of triggers and release kinetics/profiles. We will explore the use of chemically distinct thiols on etalons to control release rates, combined with tailoring of the microgel chemistry, to yield release devices with incredible diversity in release profiles. We will also embark on a new research endeavour for the group, by generating microgels that have the ability to trigger macrophage polarization for novel disease treatments. Theme 3 will focus on generating materials capable of triggered actuation and locomotion. These technologies will exploit SRPs as well as shape memory metal alloys to achieve such behaviors. In addition to these well-defined themes, my group will always be looking to discover new materials, and new applications of the materials, to make for a better environment and improved human health.