Hyaluronan Scaffold for Regenerating Elastin Matrices

描述（由申请人提供）：由于机械损伤或获得性疾病（例如，动脉瘤）或其先天性缺失或畸形可严重损害血管弹性和对形态发生、损伤反应和炎症重要的弹性蛋白介导的细胞信号传导。弹性蛋白在去弹性化血管内和组织工程构建物内的再生受到成体血管平滑肌细胞（VSMC）的不良弹性蛋白输出的限制。此外，细胞支架材料，可以上调弹性蛋白的合成，并提供必要的生物线索，再生天然弹性蛋白基质的忠实模仿尚未确定。以前我们确定，高度生物相容性，交联支架（hylans）含有透明质酸（HA），ECM中的糖胺聚糖，刺激培养的VSMC合成天然弹性蛋白的密切模仿。有证据表明，HA片段，而不是本地长链HA引起这些弹性反应，虽然长链HA可能有利于基质稳定。然而，含有长链HA和HA片段的混合物的弹性生成支架的进一步制造取决于阐明（i）表面栓系的HA或/和HA片段对成体VSMC的弹性生成的不同作用，这对于优化支架组成是重要的，（ii）在预对准的3D HA支架内的细胞培养比在2D表面上的细胞培养对模拟血管弹性蛋白超微结构的潜在益处，和（iii）同时提供的机械和生物化学线索对合成弹性蛋白基质的质量（量、结构、耐久性和力学）的影响。目的：本项目的目的是阐明上述参数对成年大鼠VSMC培养模型中弹性蛋白合成的影响。目的1将优化HA片段的大小分布内的表面拴系的混合物的HA的基础上，他们的个人影响弹性蛋白合成成人RVSMCs。目标2将研究管状电纺HA支架的独立和组合益处，所述管状电纺HA支架含有目标1中确定的优化组合物、循环机械应变和生长因子（TGF-β，IGF-1）补充剂以提高基质质量。重要性：研究结果将创建一种工具，可以与现有的血管设备集成，以根据需要制造天然弹性蛋白的忠实模拟物。这种弹性蛋白模拟物将有助于增强和修复变性血管中的弹性蛋白，并且还可用于研究弹性发生的体外模型。

DESCRIPTION (provided by applicant): The disruption of vascular elastin matrices due to mechanical injury or acquired diseases (e.g., aneurysms), or their congenital absence or malformation can severely compromise vessel elasticity and elastin-mediated cell signaling important to morphogenesis, injury response, and inflammation. Regeneration of elastin within de-elasticized vessels and within tissue-engineered constructs is limited by the poor elastin output by adult vascular smooth muscle cells (VSMCs). Also, cell scaffold materials that can upregulate elastin synthesis and provide biologic cues necessary to regenerating faithful mimics of native elastin matrices are yet to be identified. Previously we determined that that highly biocompatible, crosslinked scaffolds (hylans) containing hyalruonan (HA), a glycosaminoglycan in the ECM, stimulates cultured VSMCs to synthesize close mimics of native elastin. Evidence suggests that HA fragments, not native long-chain HA elicit these elastogenic responses, although long-chain HA possibly facilitates matrix stabilization. The further fabrication of elastogenic scaffolds containing a mixture of long-chain HA and HA fragments, is however contingent on elucidating (i) the differential effects of surface tethered HA or/ and HA fragments on elastogenesis by adult VSMCs, important to optimizing scaffold composition, (ii) the potential benefits of cell culture within prealigned 3D HA scaffolds than on 2D surfaces, to mimicking vascular elastin ultrastructure, and (iii) the impact of concurrently provided mechanical and biochemical cues on the quality (amount, structure, durability, and mechanics) of the synthesized elastin matrix. AIMS: The objective of this project is to clarify the impact of the above parameters on elastin synthesis in an adult rat VSMC culture model. Aim 1 will optimize the HA-fragment size distribution within surface-tethered mixtures of HA based on their individual effects on elastin synthesis by adult RVSMCs. Aim 2 will investigate the standalone and combined benefits of tubular, electrospun HA nanofiber scaffolds containing the optimized composition determined in Aim 1, cyclic mechanical strain, & growth factor (TGF-b, IGF-1) supplements to matrix quality. SIGNIFICANCE: The study outcomes will create a tool that can be integrated with existing vascular devices to fabricate faithful mimics of native elastin on demand. Such elastin mimics will be useful to augument and repair elastin in degenerated vessels, and also make available an in vitro model to study elastogenesis.