Engineered Sense and Response Circuits for Stem Cell-Based Tissue Regeneration and Repair

摘要 再生医学疗法寻求用工程替代品取代细胞或病理组织，但 目前还不存在精确协调移植细胞活动的可靠方法。这一点在 由慢性疾病引起的病理状态，在这些疾病中，正常的体内平衡和再生信号 被有害信号覆盖，导致细胞死亡和器官功能丧失。这项提案的目标是 是开发将干细胞和它们的环境之间高度特异的相互作用结合起来的技术 具有程序化的细胞输出，如归巢、分化、基质合成和细胞因子/生长 因子分泌。我们已经开发了一种合成受体平台，使细胞能够识别配体 通过精心挑选的单链可变片段(ScFv)所赋予的特异性。在订婚时 通过这种scFv受体固定的配体(膜或底物)，工程细胞部署 预定义的程序，规定细胞与细胞或细胞与基质相互作用的结果。虽然我们已经使用了这个 在其他类型的细胞中驱动各种行为的平台，我们还没有确定它对指导干细胞的效用 与再生医学相关的功能。我们假设这个人工感官平台可以 使干细胞能够自主地执行再生程序，如归巢、分化或 基质合成，响应细胞-细胞和细胞-生物材料的相互作用。在具体目标1中，我们将确立 我们能够将特定的外部信号与干细胞状态的特定变化联系起来，包括迁移， 分化和细胞外基质合成。在具体目标2中，我们将纳入由 将我们的合成感受器植入生物材料支架。通过这种方式，我们将生产蜂窝递送车辆和 组织工程支架使细胞能够自我选择程序化的行为， 与上下文相关的特异性和精确度。通过实现这一新颖的感知和响应系统 再生医学策略，我们打算生产能够自主检测的干细胞疗法 微环境的特征，并以恢复功能的协调再生程序响应， 即使在没有基于细胞的修复通常所需的提示的情况下。这笔奖学金将为我提供 经验和工具对我的目标至关重要，我要发展成为一名多产的、独立的科学家，同时 为基于干细胞和生物材料引导的组织再生和修复提供关键见解。

ABSTRACT Regenerative medicine therapies seek to replace cells or pathological tissues with engineered substitutes, but robust methods for precisely orchestrating activities of transplanted cells do not exist. This is especially true in pathological conditions that arise from chronic diseases, in which normal homeostatic and regenerative cues are overridden by deleterious signals, leading to cell death and loss of organ function. The goal of this proposal is to develop technologies that couple highly specific interactions between stem cells and their environments with programmed cellular outputs, such as homing, differentiation, matrix synthesis, and cytokine / growth factor secretion. We have developed a synthetic receptor platform that allows cells to recognize ligands through specificity imparted by carefully selected single chain variable fragments (scFv). Upon engagement of immobilized ligand (either membrane- or substrate-tethered) by this scFv receptor, engineered cells deploy a pre-defined program that dictates the outcome of cell-cell or cell-matrix interactions. Though we have used this platform to drive various behaviors in other cell types, we have not established its utility for guiding stem cell functions that are pertinent to regenerative medicine. We hypothesize that this synthetic sensory platform can enable stem cells to autonomously implement regenerative programs, such as homing, differentiation, or matrix synthesis, in response to cell-cell and cell-biomaterial interactions. In Specific Aim 1, we will establish our ability to link specific external signals to defined changes in stem cell states, including migration, differentiation, and extracellular matrix synthesis. In Specific Aim 2, we will incorporate ligands recognized by our synthetic receptors into biomaterial scaffolds. In this way, we will produce cellular delivery vehicles and tissue engineering scaffolds that enable the cells to self-select programmed behaviors with engineered, context-dependent specificity and precision. By implementing this novel sense and response system in regenerative medicine strategies, we intend to produce stem cell therapies capable of autonomously detecting features of a microenvironment and responding with a coordinated regenerative program that restores function, even in the absence of cues normally required for cell-based repair. This fellowship will provide me with the experience and tools critical for my goal of developing into a productive, independent scientist while also contributing key insights toward stem cell-based and biomaterial-guided tissue regeneration and repair.