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

项目概要 纤维化疾病是全球发病率和死亡率的重要来源。特发性肺病 纤维化（IPF）是一种慢性、进行性、危及生命的肺部疾病，在老年人群中最常见。 仅在美国，IPF 就影响了 100,000 名患者，全球每年新增约 34,000 例确诊病例 年。大多数 IPF 患者会在 3-5 年内死于呼吸衰竭，这是临床上唯一可用的治疗方法。 治疗方法不能治愈该疾病。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新治疗靶点 模型有一些局限性，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 体外驱动纤维化进展：尚不清楚，例如，细胞外基质的变化是否 (ECM) 成分或周围组织机械性能的后续变化是 IPF 更有效的驱动因素，即治疗的最佳目标。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尚未解决的挑战。 我的实验室开发了合成和微加工新型生物材料的新方法 进行动态细胞 ECM 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 平台将光可调聚乙二醇 (PEG) 主链与可点击的脱细胞 ECM 相结合 (dECM) 从健康或患病的肺组织中分离出来，以便我们可以分离纤维化组织成分（例如， 机械性能的后续变化（例如增加的刚度）导致胶原蛋白含量增加）。 具体来说，健康或 IPF 肺 dECM 将被纳入模拟软（1-5 kPa）水凝胶基质中 健康组织，然后暴露于聚焦光下将动态地引发硬化至纤维化水平（>10 kPa）。 提出了三个目标来设计和实施这种基于生物材料的策略，以构建新型、高 IPF 体外保真模型。目标 I：设计 PEG- 的结构、组成和动态力学 dECM 细胞培养平台可再现远端肺组织；目标 II：询问成分的影响和 使用动态 PEG-dECM 生物材料平台研究成纤维细胞活化的机械特性；和目标 III： 识别动态 3D 模型中重建的纤维化活动的可药物机械敏感目标。成功 完成这些目标将增进我们对 IPF 的细胞和分子驱动因素的理解，建立 为精准医疗的高通量发现和筛选疗法奠定了基础。

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.