Development of a wound-on-chip model to study stromal-epithelial interactions during tissue repair

这项提议的目标是设计一种新的体外仿生伤口愈合模型，以研究人类 成纤维细胞和上皮细胞在细胞和分子水平上协调组织闭合。体内创面愈合 是一个动态的形态发生过程，目的是关闭和修复受损的组织。关键阶段 在组织闭合过程中是伤口的再上皮化，这是一个上皮细胞在伤口上迁移的过程 裸露伤口床，以恢复屏障。伤口不能再上皮化导致慢性伤口 这种情况每年影响600万美国人，估计造成250亿美元的损失 每年用于医疗系统的费用。因此，对驱动再上皮化的机制的理解一直是 伤口愈合研究的中心焦点。由于动物模型的局限性，体外模型已经被 用于研究人类上皮细胞的再上皮化。传统模式，如划伤伤口 检测，包括刮除附着在平面底物上的单层上皮细胞，以及 迁移细胞以重新填充划痕被衡量为愈合的指标。在更高级的共同文化模式中， 用成纤维细胞负载的胶原水凝胶或真皮组织外植体替换平面基质。 虽然这些模型有一个预先定义的底物作为上皮细胞的迁移基础，但体内研究已经 显示，对于全层伤口，较深的纤维层必须首先通过形成 肉芽组织通过成纤维细胞，在上皮细胞可以在这个临时组织上迁移以关闭 伤口。因此，在活体环境中，重新上皮化发生在成纤维细胞沉积临时模板和 成纤维细胞和上皮细胞之间的相互作用协调这两个组织层的关闭。 目前的体外模型没有捕捉到这种复杂的组织动力学。考虑到对再上皮化的依赖 在下面的基质上，我们假设成纤维细胞在创伤过程中介导了再上皮化的速度。 结案了。为了解决这一假设，我们在目标1中建议建立一个仿生的体外伤口闭合模型。 其中，在受伤的工程微组织中，重新上皮化随后进行纤维组织修复，以模拟愈合 全身的伤口。在目标2中，我们将使用最先进的基因组编辑技术来阐明成纤维细胞- 调节纤维组织闭合和再上皮化的上皮相互作用。这些研究也将验证 并将我们的3D仿生模型与其他伤口愈合模型进行基准比较。在目标3中，我们将探讨 来自不同健康和病理组织来源的成纤维细胞影响我们的仿生组织中的再上皮化 模特。最终，该项目旨在为优化缠绕床奠定基础，使其能够快速恢复 上皮化是促进组织再生和减少疤痕的范例。

The goal of this proposal is to engineer a novel in vitro biomimetic wound healing model to study how human fibroblasts and epithelial cells coordinate tissue closure at the cellular and molecular level. In vivo wound healing is a dynamic morphogenetic process with the goal to close and restore the damaged tissue. A critical stage during tissue closure is re-epithelialization of wounds, a process by which epithelial cells migrate over the denuded wound bed, to restore the barrier. Failure of wounds to re-epithelialize results in chronic wound formation, a condition that affect 6 million Americans annually and carries an estimated cost of US $25 billion per year for the medical system. Hence, understanding the mechanisms that drive re-epithelialization has been a central focus in wound healing research. Due to limitations with animal models, in vitro models have been instrumental to study re-epithelialization by human epithelial cells. Traditional models, such as the scratch wound assay, involve scratching of a monolayer of epithelial cells adherent to a planar substrate, and the time for migrating cells to repopulate the scratch is measured as a proxy for healing. In more advanced co-culture models, the planar substrate is either replaced by a fibroblast-laded collagen hydrogel or by a dermal tissue explant. Whereas these models have a pre-defined substrate as a migration base for epithelial cells, in vivo studies have shown that for full-thickness wounds, the deeper fibrous layers must heal first through the formation of granulation tissue by fibroblasts, before epithelial cells can migrate over this provisional tissue to close the wound. Thus, in in vivo settings, re-epithelialization occurs as fibroblasts deposit a provisional template and reciprocal interactions between fibroblasts an epithelial cells coordinate closure of these two tissue layers. Current in vitro models don't capture this intricate tissue dynamics. Given the dependency of re-epithelialization on the underlying substrate, we hypothesize that fibroblasts mediate the rate of re-epithelialization during wound closure. To address this hypothesis, we propose in aim 1 to build a biomimetic in vitro wound closure model wherein re-epithelialization ensues fibrous tissue repair in wounded engineered microtissues to emulate healing of full thickness wounds. In aim 2, we will use state-of-the art genome editing techniques to elucidate fibroblast- epithelial interactions that regulate fibrous tissue closure and re-epithelialization. These studies will also validate and benchmark our 3D biomimetic model to other wound healing models. In aim 3, we will explore whether fibroblasts from different healthy and pathological tissue sources affect re-epithelialization in our biomimetic model. Ultimately, this project aims to establish a basis for optimizing a wound bed that enables rapid re- epithelialization as a paradigm for promoting tissue regeneration and minimizing scarring.