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Electrostatically triggered hydrophobic self-assembly of protein hydrogels

静电触发蛋白质水凝胶的疏水自组装

基本信息

批准号：
8461421
负责人：
Kevin Baler
金额：
$ 3.52万
依托单位：
NORTHWESTERN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-03-19 至 2014-03-18
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8461421
关键词：
Address Albumins Area Binding Biocompatible Biocompatible Materials Biological Biological Process Blood Cells Cereals Characteristics Charge Chemicals Complex Data Development Dialysis procedure Electrostatics Filtration Foundations Gel Genetic Engineering Goals High temperature of physical object Hydrogels Hydrophobic Interactions Hypoxia Impairment In Situ Kinetics Laboratories Measures Mechanics Mediating Medical Device Methods Modeling Modification Myoglobin Necrosis Organism Oxygen Physiological Population Principal Investigator Process Property Proteins Research Series Structure System Techniques Temperature Testing Time Tissue Engineering Vascular Graft Vascularization Work Wound Healing base design globular protein health care quality improved interest meetings molecular dynamics next generation novel practical application predictive modeling research study scaffold self assembly simulation spectroscopic imaging success

项目摘要

DESCRIPTION (provided by applicant): Oxygen depletion deep within 3D tissue engineered scaffolds limits the viability of embedded cells, causing localized necrosis. The development of new biomaterials that can deliver oxygen locally to these cells in a physiological manner will mitigate oxygen depletion and necrosis in these cell populations. Our laboratories have recently been investigating in situ-forming protein hydrogels and novel mechanisms for globular protein self-assembly that utilize changes in electrostatic charges and hydrophobic interactions to form a hydrogel at physiological temperatures. Under the proper controlled pH conditions, the partially denatured proteins will maintain the necessary secondary structure that will be needed for function. This proposal will utilize this new understanding of induced protein self-assembly to develop a new albumin/myoglobin-based scaffold that can deliver oxygen on demand by neighboring cells. Albumin has been extensively characterized, is readily available via isolation from blood or via recombinant DNA technology, biocompatible, and has been used in medical devices such as vascular grafts while myoglobin is well characterized and readily available oxygen carrying globular protein. In order to rationally design the hydrogel for this purpose a combination of theoretical and experimental approaches will be used to evaluate these new materials while providing fundamental framework for understanding and designing better protein hydrogel materials. Based on preliminary results, we suspect there are fundamental limitations to the types and/or size of proteins that can be used as pH-induced hydrogel forming building blocks. To delineate those boundaries, we will a) perform a series of systematic atomistic molecular dynamics simulations to determine the structure of the pH denatured albumin and myoglobin, b) build coarse-grained models from the atomistic simulations, and perform Brownian Dynamics simulations to study gel formation and their mechanical properties for albumin and myoglobin, c) experimentally study the formation of the protein gels, measure their mechanical properties and test the predictions from the simulations, use these results for fine tuning of the model, d) predict and fabricate the optimal conditions for formation of denatured albumin based gels with functional myoglobin proteins, e) characterize the stability of incorporated myoglobin, and f) assess oxygen binding and release kinetics from the hydrogel. This research is a true integration of theoretical and experimental approaches to solve a problem: theoretical atomistic and coarse-grained protein representations in combination with superior computational power currently allow simulation of systems of biologically relevant size and timescale while advanced imaging and spectroscopic techniques enable direct comparison between simulations and experiments. The development of reliable and predictive models will enable the simulations to predict and guide the design of improved biomaterials. The techniques developed in this proposal lay the foundation for the design of additional functional protein hydrogel scaffolds for applications in areas such as wound healing and dialysis.

描述（由申请人提供）：3D组织工程支架内部深处的氧气耗尽限制了嵌入细胞的活力，导致局部坏死。能够以生理方式将氧气局部输送到这些细胞的新生物材料的开发将减轻这些细胞群中的氧气耗尽和坏死。我们的实验室最近一直在研究原位形成蛋白质水凝胶和球状蛋白质自组装的新机制，这些机制利用静电荷和疏水相互作用的变化在生理温度下形成水凝胶。在适当控制的pH条件下，部分变性的蛋白质将保持功能所需的必要二级结构。该提案将利用这种对诱导蛋白质自组装的新理解来开发一种新的基于白蛋白/肌红蛋白的支架，该支架可以根据邻近细胞的需求提供氧气。白蛋白已被广泛表征，易于通过从血液中分离或通过重组DNA技术获得，具有生物相容性，并已用于医疗器械，如血管移植物，而肌红蛋白已被充分表征并易于获得携氧球状蛋白。为了合理地设计用于此目的的水凝胶，将使用理论和实验方法的组合来评估这些新材料，同时为理解和设计更好的蛋白质水凝胶材料提供基本框架。基于初步结果，我们怀疑可用作pH诱导的水凝胶形成构建块的蛋白质的类型和/或大小存在根本限制。为了描绘这些边界，我们将a）执行一系列系统的原子分子动力学模拟以确定pH变性的白蛋白和肌红蛋白的结构，B）从原子模拟构建粗粒度模型，并执行布朗动力学模拟以研究白蛋白和肌红蛋白的凝胶形成及其机械性质，c）实验研究蛋白质凝胶的形成，测量它们的机械性能并测试模拟的预测，使用这些结果对模型进行微调，d）预测并制造形成具有功能性肌红蛋白的变性白蛋白基凝胶的最佳条件，e）表征掺入的肌红蛋白的稳定性，和f）评估水凝胶的氧结合和释放动力学。这项研究是一个真正的整合的理论和实验方法来解决一个问题：理论原子和粗粒度的蛋白质表示结合上级计算能力目前允许模拟系统的生物相关的大小和时间尺度，而先进的成像和光谱技术，使模拟和实验之间的直接比较。可靠和预测模型的开发将使模拟能够预测和指导改进生物材料的设计。该提案中开发的技术为设计用于伤口愈合和透析等领域的其他功能性蛋白质水凝胶支架奠定了基础。