Hybrid Hydrogel Biomaterials Comprising Clickable Decellularized Extracellular Matrix for Engineering Dynamic 3D Models of Fibrosis

项目总结 纤维性疾病是全球发病率和死亡率的重要来源。特发性肺 纤维化(IPF)是一种慢性、进行性和危及生命的肺部疾病，最常见于老年人群。 仅在美国就有100,000名IPF患者受到影响，全球约有34,000例新诊断病例 年。大多数IPF患者在3-5年内死于呼吸衰竭，这是临床上唯一可用的 治疗方法不能治愈这种疾病。随着美国人口平均年龄的增加， 研究人员和从业者必须共同努力，确定阻止或逆转IPF的新目标。 通过传统细胞培养技术和临床前动物发现IPF的新治疗靶点 模型有几个局限性，因为这些系统不能充分再现人类的关键方面 生理学。最重要的是，动态的细胞-基质和细胞-细胞相互作用很难概括 体外推动纤维化的进展：例如，尚不清楚细胞外基质是否发生变化 (ECM)成分或随之而来的周围组织机械性能的变化是 IPF的更强大的驱动力，即治疗的最佳靶点。新的工具和技术使我们能够 随着时间的推移，动态研究纤维化的发病机制仍然是一个悬而未决的挑战。 我的实验室已经开发出新的方法来合成和微制造一类新的生物材料，以 进行动态细胞-细胞外基质研究，这在传统的纤维化模型中目前是不可能的。我们的创新 平台结合了可光调的聚乙二醇(PEG)主干和可点击的脱细胞ECM (DECM)从健康或患病的肺组织中分离，以便我们可以分离纤维化组织成分(例如， 由于随后机械性能的变化(例如，僵硬增加)，导致胶原含量增加)。 具体地说，健康的或IPF肺DECM将被加入到软(1-5kpa)水凝胶基质中，以模拟 健康的组织，然后暴露在聚焦的光下会动态地启动硬化到纤维化水平(&gt；10kpa)。 提出了三个目标来设计和实施这一以生物材料为基础的战略，以建立新的、高质量的 特发性肺纤维化体外模型的保真性。目标一：设计聚乙二醇组分的结构、组成和动态力学- DECM细胞培养平台重现远端肺组织；目的II：询问成分和 利用动态聚乙二醇二乙醇胺生物材料平台激活成纤维细胞的力学特性；以及目的III： 确定在动态3D模型中重建的纤维化活动的可用药机械敏感靶点。成功 这些目标的完成将促进我们对IPF的细胞和分子驱动因素的理解， 高通量发现和筛选精准医疗疗法的基础。

PROJECT SUMMARY Fibrotic disorders account for a significant source of global morbidity and mortality. Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and life-threatening lung disease most prevalent in elderly populations. IPF impacts 100,000 patients in the U.S. alone and there are approximately 34,000 new global diagnoses each year. Most patients with IPF succumb to respiratory failure within 3-5 years and the only clinically available therapeutic treatments do not cure the disease. As the average age of the U.S. population increases, it is imperative for researchers and practitioners to work together to identify new targets to halt or reverse IPF. Discovery of new therapeutic targets for IPF through traditional cell culture techniques and pre-clinical animal models has several limitations because these systems do not adequately reproduce key aspects of human physiology. Most importantly, dynamic cell-matrix and cell-cell interactions that are difficult to recapitulate in vitro drive the progression of fibrosis: it is not clear, for example, whether changes in the extracellular matrix (ECM) composition or the subsequent alterations in mechanical properties of the surrounding tissues are the more potent drivers of IPF, i.e., the best target for therapeutics. New tools and technologies that enable us to dynamically study the pathogenesis of fibrosis over time remain an unresolved challenge. My laboratory has developed novel methods to synthesize and microfabricate a new class of biomaterials to conduct dynamic cell-ECM studies, not currently possible in traditional models of fibrosis. Our innovative platform combines a phototunable poly(ethylene glycol) (PEG) backbone with clickable decellularized ECM (dECM) from healthy or diseased lung tissue so that we may decouple fibrotic tissue composition (e.g., increased collagen content) from subsequent changes in mechanical properties (e.g., increased stiffness). Specifically, healthy or IPF lung dECM will be incorporated into soft (1-5 kPa) hydrogel matrices that mimic healthy tissue, then exposure to focused light will dynamically initiate stiffening to fibrotic levels (>10 kPa). Three aims are proposed to engineer and implement this biomaterials-based strategy for building novel, high- fidelity in vitro models of IPF. AIM I: Engineer the structure, composition, and dynamic mechanics of PEG- dECM cell culture platforms to recapitulate distal lung tissue; AIM II: Interrogate the impact of composition and mechanical properties on fibroblast activation using dynamic PEG-dECM biomaterial platforms; and AIM III: Identify druggable mechanosensitive targets of the fibrotic activity recreated in dynamic 3D models. Successful completion of these aims will advance our understanding of the cellular and molecular drivers of IPF, building the foundation for high-throughput discovery and screening of therapeutics for precision medical treatments.