CAREER: Probing Mechanisms of Beta Cell Dysfunction via Quantitative Droplet Molecular Transport

在糖尿病中，胰腺中的特化细胞（称为β细胞）的胰岛素分泌受损，这种损害可能与β细胞周围局部环境中的化学因素有关。 特别重要的是糖尿病的两个常见风险因素：脂肪饮食（脂肪酸）和缺乏足够的氧气。 在这个项目中，一种新型的微型泵将精确地控制β细胞的局部环境，从而可以定量和精确地研究糖尿病的机制。 研究结果将改变对糖尿病如何发展的理解，并可能解释为什么尽管有类似的风险因素，但并非所有肥胖患者都会患糖尿病。这些新的和变革性的生物医学科学和工程调查（或实验）将由一个跨学科的同行学习的学生团队进行，在主要研究者的指导下。研究也与教育交织在一起，研究生，本科生，当地高中和小学的学生都参与了该项目的实验，解释和同伴教学方面。该提案侧重于探索β细胞功能障碍的机制，这是糖尿病的标志，通过在基于PI的“智能微凝胶”的高度集成平台“定量液滴分子转运（qDMT）”中进行的研究，液滴和新型微流体特斯拉泵。 初步研究的两种机制是1）由于新抗原与游离脂肪酸（FFA）暴露的β细胞结合而导致的免疫原性增强，以及2）由于FFA和缺氧在调节脂肪细胞细胞因子中的潜在协同作用而导致的β细胞损伤。 qDMT是用于原位定量蛋白质转运的独特工具，这归因于三个新特征：1）智能微凝胶允许在原位修饰抗原的同时测定抗体结合，即，在多孔液滴内，微珠生物传感器可紧邻感兴趣的细胞放置，因此扩散长度显著缩短，加速了原位敏感蛋白质检测; 2）无叶片特斯拉泵优化了边界层的使用，实现了完全密封，传统泵难以实现连续流动，以及3）微通道尺寸可以变化以创建可预测的扩散模型来量化分子动力学。该研究计划围绕三个目标组织：1）工程师qDMT与细胞生物传感器负载智能微凝胶，微特斯拉泵和可重构微流体。2)应用qDMT研究FFA暴露的β细胞中的新抗原（胰岛素、GAD、IA-2、ZnT 8）结合; 3）应用qDMT研究脂肪细胞因子（IL 6、TNF α）调节β功能障碍中的FFA+缺氧协同作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In diabetes, insulin secretion is impaired in specialized cells (called beta cells) in the pancreas, and this impairment may be related to chemical factors in the local environment around the beta cells. Of particular importance are two common risk factors of diabetes: a fatty diet (fatty acids) and lack of sufficient oxygen. In this project, a novel miniaturized pump will precisely control the beta cells' local environment so that the mechanisms of diabetes can be studied quantitatively and precisely. Results of the research will transform understanding of how diabetes develops and may explain why not all obese patients develop diabetes despite similar risk factors. These novel and transformative biomedical science and engineering investigations (or experiments) will be conducted by a team of interdisciplinary, peer-learning students, under the guidance of the principle investigator. Research is also interwoven with education, where students from graduate, undergraduate, local high school, and elementary school all participate in the experimental, interpretive, and peer-teaching aspects of the project.The proposal focuses on probing mechanisms of beta cell dysfunction, a hallmark of diabetes, through studies performed in a highly integrated platform termed "quantitative droplet molecular transport (qDMT)" based on the PI's "smart microgel" droplets and a novel microfluidic Tesla pump. The two mechanisms for initial study are 1) enhanced immunogenicity as a result of neoantigen binding to free fatty acid (FFA) exposed beta cells and 2) beta cell impairment as a result of a potential synergy between FFA and hypoxia in modulating adipocyte cytokines. The qDMT is a unique tool for quantifying protein transport in situ due to three novel features:: 1) Smart microgels allow antibody binding to be assayed while modifying the antigens in situ, i.e., within the porous droplets, bead biosensors can be placed right next to cells of interest so the diffusion length is dramatically shortened, accelerating sensitive protein detection in situ; 2) The miniaturizing bladeless Tesla pump optimizes use of boundary layers, enabling a completely sealed, continuous flow difficult to achieve with conventional pumps and 3) Microchannel dimensions can be varied to create predictable diffusion models to quantify molecular kinetics. The Research Plan is organized around three objectives: 1) Engineer qDMT with cell & biosensor laden smart microgels, a micro-Tesla pump and reconfigurable microfluidics. 2) Apply qDMT to study neoantigen (insulin, GAD, IA-2, ZnT8) binding in FFA exposed beta cells and 3) Apply qDMT to study FFA+hypoxia synergy in adipocyte cytokine (IL6, TNFá) modulation of beta dysfunction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.