DNA-Hyaluronic Acid Platform for Spatiotemporally Probing the Role of Adhesion Ligands on BMP-Induced Osteogenesis In Vitro

项目摘要 组织工程学的进展一直受到限制，部分原因是生物分子控制方面的挑战。 对再生很重要的信号。特别是，用于骨修复的组织工程方法已经被 被所需的生长因子骨形态发生蛋白-2(BMP-2)超生理剂量抑制 由于交付效果不佳，需要进行适当的治疗。在天然细胞外基质(ECM)中，BMP-2紧密结合 受蛋白质和糖胺聚糖结合，其呈现在空间和时间上调节增强 生物活性。此外，研究人员已经显示出与其他信号分子的显著协同作用，例如 细胞-基质或细胞-细胞黏附配体。为了模拟这些交互作用，有许多优雅的方法基于 光化学和正交化学已被发展用于呈现生物分子。然而， 这些方法依赖于高度定制的化学反应(这可能很难使用 多种生物分子)，并且通常限于1-2个信号。它们通常还基于 用于时间控制的光解反应，这排除了它们在多个循环中的可逆性。给定 控制细胞命运的细胞外环境的复杂性(例如，干细胞的“生态位”)，一般 可以在两个空间中控制三个或更多信号以及多种类型生物分子的体外平台 而时间对于梳理出控制细胞增殖、迁移、 分化，并形成新的组织。我们建议开发一种基于生物材料的体外平台 独立且可逆地控制生长因子骨的时空呈现 形态发生蛋白-2(BMP-2)与RGDS多肽结合以模拟细胞-基质黏附和 HAVDI多肽模拟细胞-细胞黏附。因此，这项工作的具体目标是：(1)调查时间 固定化BMP-2对成骨的影响以及(2)确定细胞-细胞和细胞-细胞的时空作用。 骨形态发生蛋白-2诱导成骨过程中的基质相互作用。

Project Summary Advances in tissue engineering have been limited, in part, due to challenges in controlling the biomolecule signals important for regeneration. In particular, tissue engineering approaches for bone repair have been inhibited by the supraphysiological doses of the growth factor bone morphogenetic protein-2 (BMP-2) required for adequate healing due to suboptimal delivery. In the native extracellular matrix (ECM), BMP-2 is tightly bound by proteins and glycosaminoglycans with its presentation regulated in space and time to enhance bioactivity. Furthermore, researchers have shown significant synergies with other signaling molecules, such as cell-matrix or cell-cell adhesion ligands. To mimic these interactions, a number of elegant approaches based on photopatterning and orthogonal chemistries have been developed for presenting biomolecules. However, these approaches rely on highly customized chemical reactions (which may be difficult to implement with multiple classes of biomolecules) and are generally restricted to 1-2 signals. They are also often based on photocleavage reactions for temporal control, which precludes their reversibility over multiple cycles. Given the complexity of the extracellular environment (e.g. the stem cell “niche”) in controlling the fate of cells, a general in vitro platform that can control three or more signals, as well as multiple types of biomolecules, in both space and time would be invaluable for teasing apart the factors that control behavior like cell proliferation, migration, differentiation, and new tissue formation. We propose to develop a biomaterial-based in vitro platform capable of independently, and reversibly, controlling the spatiotemporal presentation of the growth factor bone morphogenetic protein-2 (BMP-2) in combination with the RGDS peptide to mimic cell-matrix adhesion and the HAVDI peptide to mimic cell-cell adhesion. Thus, the specific aims of the work are: (1) Investigate the temporal effect of immobilized BMP-2 on osteogenesis and (2) Determine the spatiotemporal role of cell-cell and cell- matrix interactions during BMP-2-induced osteogenesis.