CAREER: Integration of Sophisticated Stimuli-Response Capabilities into Highly-Distensible Nanostructured Hydrogels

技术概述：响应性水凝胶技术目前正在一系列应用中寻求，包括组织支架、化学释放剂、生物传感器和人造肌肉。然而，由于无法以受控的方式引入准确和可调的响应机制，它们的功效受到严重限制。这通常归因于大多数系统的固有的不明确的结构，其中凝胶化基于材料内的空间随机交联，或者形成不良的固相域不均匀地分布在整个样品中。该CAREER奖项中提出的研究活动的最终目标是成功产生一类新的高度膨胀的纳米结构水凝胶，能够对一系列外部刺激做出复杂和可调的反应。第一代水凝胶是通过利用形成嵌段共聚物两亲物的球体的熔融状态自组装来制造的，作为用于更高功能材料的极其通用的模板。我们的目标是产生具有集成功能的水凝胶，允许人们通过外部刺激（例如，温度、pH、光照等），这些凝胶中溶液相和固相的尺寸、几何形状和尺寸分布，所有这些都受到严格控制。同时，我们的目标是将内部触发器，可以诱导更激烈的材料响应外部刺激，如快速和不连续的变化，体积，模量，或域渗透性。这些想法的扩展到非球形形态，预计提供访问的材料，其中各向异性溶胀控制是可能的。虽然初步的工作重点是基本水凝胶的合成和评价其固有的响应特性，工作的优势将集中在先进的响应机制的整合，通过合成改性的组成嵌段共聚物在分子水平上。拟议的研究将有助于促进有关下一代“智能”或响应材料设计的知识，这些材料能够同时进行多种刺激诱导行为，包括：溶解，溶胀各向异性，连续和不连续的膨胀（和收缩），弯曲（和不弯曲），可逆的自粘附，形状恢复和可重复的化学释放。非技术摘要：这项职业奖中提出的研究旨在成功产生一类新的超吸收聚合物材料，这些材料具有改变其最基本特性的独特能力，例如形状，尺寸，韧性和渗透性，直接响应于施加的刺激，例如紫外线，热或电场，仅举几例。这些材料预计将在先进的药物输送，改善植入物的相容性，可降解的组织支架，人造肌肉，化学和生物传感器，生物催化等方面有直接的影响。因此，拟议的研究预计将在一些重要的技术领域产生广泛的影响，在这些领域中，社会生活质量可能会受到深刻影响。这些研究活动将与各种能力的学生教育相结合，努力将发现的元素带到有前途的年轻研究人员的学习中。例如，本科生作为积极的研究人员在这个项目上，结果直接整合到课程的课程，并通过本科生，研究生和部门的研讨会在全国和世界各地的结果传播广泛纳入允许这个前沿的研究，成为一个主流的学习工具。此外，该职业奖还用于为地区（科罗拉多和怀俄明州）高中科学教师举办为期一天的年度互动研究研讨会，在研讨会上，可以与世界专家讨论纳米技术、生物技术和生物材料方面的最新主题。这些研讨会的目标是为每位教师提供实践材料，使最新的研究在他们自己的教室里栩栩如生，这样高中生就能够在科罗拉多州立大学和世界各地分享最新研究的兴奋。

TECHNICAL SUMMARY:Responsive hydrogel technologies are currently being pursued in a range of applications, including tissue scaffolds, chemical release agents, biosensors, and artificial muscles. However, their efficacy has been severely restricted by an inability to introduce accurate and tunable response mechanisms in a controlled fashion. This is often attributable to the inherently ill-defined structure of most systems, with gelation based on spatially random cross-links within the material, or poorly formed solid phase domains distributed non-uniformly throughout the sample. The ultimate goal of the research activities proposed in this CAREER award is the successful generation of a new class of highly distensible, nanostructured hydrogels, capable of sophisticated and tunable responses to a range of external stimuli. The first generation of hydrogels are to be fabricated by exploiting the melt-state self-assembly of sphere forming block copolymer amphiphiles, as extremely versatile templates for more highly functioning materials. Our goal is to generate hydrogels with integrated functionality permitting one to continuously tune, through external stimuli (e.g., temperature, pH, light, etc.), the dimensions, geometry, and size distribution of both the solution and solid phases in these gels, all with exacting control. At the same time, we aim to incorporate internal triggers that can induce more drastic material responses to an external stimulus, such as rapid and discontinuous changes in volume, modulus, or domain permeability. Extension of these ideas to non-spherical morphologies is expected to provide access to materials in which anisotropic swelling control is possible. While the preliminary work proposed focuses on the synthesis of the basic hydrogels and evaluation of their inherent response characteristics, the predominance of the work will be focused on the integration of advanced response mechanisms through synthetic modifications to the constituent block copolymers at the molecular level. The proposed research will be instrumental in the advancement of knowledge concerning the design of next generation, "intelligent" or responsive materials, capable of multiple simultaneous stimulus-induced behaviors, including: dissolution, swelling anisotropy, continuous and discontinuous expansion (and contraction), bending (and unbending), reversible self-adhesion, shape recovery, and triggerable chemical release. NON-TECHNICAL SUMMARY:The research proposed in this CAREER award is directed at the successful generation of a new class of super-absorbent polymeric materials that possess the unique capability of changing their most basic characteristics, such as shape, size, toughness, and permeability in direct response to an applied stimulus, such as UV light, heat, or an electric field, to name just a few. These materials are anticipated to have direct implications in advanced drug delivery, improved implant compatibility, degradable tissue scaffolds, artificial muscles, chemical and biological sensors, and biocatalysis. Thus, the proposed research is expected to have broad impact in a number of technologically important areas in which societal quality of life can be deeply affected. These research activities will be integrated with student education in a range of capacities, in an effort to bring the element of discovery in learning to promising young researchers. For example, the extensive inclusion of undergraduate students as active researchers on this project, integration of the results directly into course curricula, and the dissemination of results through undergraduate, graduate, and departmental seminars around the country and world permit this cutting edge research to become a mainstream learning tool. In addition, this CAREER award is also being used to develop annual one-day interactive research workshops for regional (Colorado and Wyoming) high school science teachers, in which recent topics in nanotechnology, biotechnology, and biomaterials can be discussed with world experts. The goal of these workshops is to provide each of the teachers with the hands-on materials to bring the latest research to life in their own classrooms, such that high school students will be able to share the excitement of the latest research at Colorado State University and around the world.