PEG Hydrogel Enabling Technologies for Guiding Endothelial Cell Function

描述（由申请人提供）：聚（乙二醇）二丙烯酸酯（PEG-DA）的合成水凝胶已显示出作为组织工程支架的巨大前景。PEG-DA水凝胶由于其生物相容性、其易于控制机械性质以及选择性地将细胞信号传导分子与天然细胞外基质（ECM）的关键功能结合的能力而理想地用于引导细胞功能。然而，聚合条件的影响，不仅对支架的材料性能，而且对生物功能分子掺入水凝胶的水平还有待阐明。因此，PEG水凝胶形成的计算模型的发展，定量预测的时空分布的物理性质和纳入生物信号将提供显着的洞察力，在确定所需的聚合条件，以优化细胞-生物材料的相互作用。可植入合成材料促进组织活力和再生的临床应用依赖于支架支持组织对氧的需求的能力以及它们诱导和促进血管生成的能力，这对于长期活力是必不可少的。内皮细胞（EC）和刺激血管生成的ECM样分子之间的协调相互作用取决于生物聚合物微结构的结构以及整合在支架中的生物活性组分的空间排列。研究还表明，血管生成可以由蛋白质的物理和趋化梯度引导。该提案旨在将PEG-DA水凝胶形成的新型计算模型与实验技术相结合，以设计具有物理性质梯度以及多个固定ECM样分子梯度的支架。这将使用界面光聚合（IP）技术作为支架方法来实现。因此，该提议旨在测试IP可用于产生具有受控交联密度梯度以及用于刺激体外血管生成的功能性生物分子的梯度组成的PEG-DA支架的假设。为了验证这一假设，我们建议开发基于自由基聚合动力学的PEG水凝胶形成的计算模型，该模型预测功能生物分子在支架中的时空掺入。这些模型将用实验数据进行验证，随后将用作指导，以根据多个输入微调这些材料的生物物理特性，以促进所需的细胞行为。将在这些支架上培养EC，并将根据梯度以及均匀交联和生物信号可用性来检查粘附、增殖、迁移和血管生成。这些模型的预测能力，以生产具有所需性能的支架，将采用严格的工程方法的高度跨学科领域的组织工程。这些研究将证明在开发生物材料，刺激治疗性血管生成的许多病理情况下，它发挥了关键作用的宝贵见解。公共卫生相关性：拟议的实验和计算水凝胶研究将提供宝贵的见解，在开发生物材料，刺激治疗性血管生成的病理情况下，它发挥了关键作用。

DESCRIPTION (provided by applicant): Synthetic hydrogels of Poly(ethylene glycol) diacrylate (PEG-DA) have shown great promise as tissue engineering scaffolds. PEG-DA hydrogels are ideal for directing cell function due to their biocompatibility, their capability to readily control mechanical properties as well as to selectively incorporate cell signaling molecules with key functionalities of the natural extracellular matrix (ECM). However, the effect of the polymerization conditions, not only on the material properties of the scaffold, but also on the level of incorporation of biologically functional molecules into the hydrogel has yet to be elucidated. Thus, the development of computational models of PEG hydrogel formation that quantitatively predict the spatio-temporal distribution of physical properties and incorporated biological signals will provide significant insight in identifying the polymerization conditions required to optimize cell-biomaterial interactions. The clinical use of implantable synthetic materials to promote tissue viability and regeneration relies on the scaffolds' capacity to support the tissue demands for oxygen and on their ability to induce and promote angiogenesis which is essential for long term viability. The coordinated interactions between endothelial cells (ECs) and the ECM-like molecules that stimulate angiogenesis are dependent upon the architecture of the biopolymer microstructure, and the spatial arrangement of the biologically active components integrated in the scaffold. Studies have also shown that angiogenesis can be guided by physical and chemotactic gradients of proteins. This proposal aims to couple novel computational models of PEG-DA hydrogel formation with experimental techniques to engineer scaffolds with gradients of physical properties as well as gradients of multiple immobilized ECM-like molecules. This will be accomplished using the technique of interfacial photopolymerization (IP) as a scaffolding approach. Thus this proposal aims to test the hypothesis that IP can be used to produce PEG-DA scaffolds with controlled gradients of crosslink density as well as gradient compositions of functional biomolecules for stimulating angiogenesis in vitro. To test this hypothesis we propose to develop computational models of PEG hydrogel formation based on the kinetics of free-radical polymerization that predict the spatio-temporal incorporation of functional biomolecules in the scaffold. These models will be verified with experimental data will be subsequently used as a guide to fine tune the biophysical properties of these materials based on multiple inputs in order to facilitate desired cell behavior. ECs will be cultured on these scaffolds and adhesion, proliferation, migration and angiogenesis will be examined as a function of gradient as well as homogeneous crosslinking and biological signal availability. The predictive capability of these models to produce scaffolds with desired properties will incorporate a rigorous engineering approach to the highly-interdisciplinary field of tissue engineering. These studies will prove invaluable insight in developing biomaterials that stimulate therapeutic angiogenesis for numerous pathologic situations in which it plays a critical role. PUBLIC HEALTH RELEVANCE: The proposed experimental and computational hydrogel studies will provide invaluable insight in developing biomaterials that stimulate therapeutic angiogenesis for pathologic situations in which it plays a critical role.