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

项目摘要 纤维化病症是全球发病率和死亡率的重要来源。特发性肺 肺纤维化（IPF）是一种慢性、进行性和危及生命的肺部疾病，在老年人群中最常见。 IPF仅在美国就影响了100，000例患者，全球每年约有34，000例新诊断 年大多数IPF患者在3 - 5年内死于呼吸衰竭， 治疗性治疗不能治愈疾病。随着美国人口平均年龄的增长， 研究人员和从业人员必须共同努力，确定新的目标，以制止或扭转IPF。 通过传统细胞培养技术和临床前动物实验发现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， physiology.最重要的是，动态的细胞-基质和细胞-细胞相互作用是很难概括的， 体外驱动纤维化的进展：目前尚不清楚，例如，细胞外基质的变化是否 (ECM)组成或周围组织的机械性质的后续改变是 IPF的更有力驱动因素，即，最好的治疗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尚未解决的挑战。 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， 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 平台结合了光可调聚（乙二醇）（PEG）骨架和可点击的脱细胞ECM 从健康或患病的肺组织中分离纤维化组织成分（dECM），使得我们可以将纤维化组织成分（例如， 增加的胶原含量）从随后的机械性能变化（例如，增加硬度）。 具体地，健康或IPF肺dECM将被掺入模拟肺的软（1 - 5kPa）水凝胶基质中。 健康组织，那么暴露于聚焦光将动态地引发硬化至纤维化水平（> 10kPa）。 提出了三个目标，工程师和实施这种基于生物材料的战略，建立新的，高， IPF体外模型的保真度。目的I：设计PEG-1的结构、组成和动态力学。 dECM细胞培养平台，以重现远端肺组织; AIM II：询问组成的影响， 使用动态PEG-dECM生物材料平台对成纤维细胞活化的机械性能;和AIM 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 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.