Characterization and Optimization of a Nanofiber-Hydrogel Composite for Tissue Remodeling

项目摘要 软组织修复是临床医生面临的重大挑战。可用的修复选项， 无论是假体还是自体，目前的主要缺点包括供体部位缺陷，不可预测的组织 存活率、有限的修复时间、假体暴露、感染和纤维化。因此，一项迫切的需求 存在一种解决方案，可以替代丢失的组织体积，同时鼓励软组织的自然重塑 随着时间的推移。我们最近开发了一种可注射纳米纤维-水凝胶复合材料(NHC)材料，它是 能够在没有脂肪细胞的情况下诱导注射到带血管软组织的体积的重塑 依赖外源生长因子和细胞。然而，它实现这一目标的机制还不够完善。 明白了。 这项拟议的项目的目标是表征免疫和组织重塑动力学 注入NHC材料，揭示其实现软组织重塑的机理(S)，并优化其 提法，以加强这一预期结果。我们将首先研究局部免疫和组织重塑 NHC引起的注射部位的动力学。这将包括表征细胞渗透，健康 细胞外基质(ECM)沉积与不规则纤维化和异物反应、炎症、 血管生成和脂肪生成。此外，我们还将揭开NHC煽动软组织的机制 通过进行单细胞RNA测序来确定候选细胞亚型和激活的信号转导的重塑 途径，然后通过免疫敲除或靶向耗尽模型确认它们 建立一种因果关系。了解软组织重塑是如何通过这种方式完成的 生物材料系统将对再生医学领域产生广泛的影响，因为我们正在努力 为组织置换创造现成的基于生物材料的解决方案。最后通过对物理信号的调制 和结构属性，以及利用我们对机械的理解，我们将优化参数 以最大化所需的软组织重塑。如果成功，这项提议将产生更好的- 架子生物刺激NHC具有增强的能力，以实现自然组织修复结果以及 从机理上理解如何实现软组织重塑，从而扩大治疗能力 并允许科学家设计用于组织替代的下一代生物材料。

Project Summary Restoration of soft tissue is a significant challenge facing clinicians. The available reparative options, whether prosthetic or autologous, present major drawbacks including donor site defects, unpredictable tissue survival, limited duration of restoration, prosthetic exposure, infection, and fibrosis. Therefore, a critical need exists for a solution which can replace missing tissue volume while encouraging natural remodeling of soft tissue over time. We have recently developed an injectable nanofiber-hydrogel composite (NHC) material which is capable of inducing remodeling of the injected volume into vascularized soft tissue with adipocytes without relying on exogenous growth factors and cells. However, the mechanisms by which it does so are not yet well understood. The goal of this proposed project is to characterize the immune and tissue remodeling kinetics of the injected NHC material, uncover the mechanism(s) by which it achieves soft tissue remodeling, and optimize its formulation to enhance this desired outcome. We will first investigate the local immune and tissue remodeling kinetics of the injected site caused by the NHC. This will include characterizing cell infiltration, healthy extracellular matrix (ECM) deposition vs. irregular fibrosis and foreign body response, inflammation, angiogenesis, and adipogenesis. In addition, we will uncover the NHC’s mechanism of instigating soft tissue remodeling by carrying out single-cell RNA sequencing to identify candidate cell subtypes and activated signaling pathways and then subsequently confirm them through immune knockout or targeted depletion models to establish a causal relationship. Gaining insight into how soft tissue remodeling can be accomplished with this biomaterial system will have wide-reaching implications for the regenerative medicine field as we work towards creating off-the-shelf biomaterials-based solutions for tissue replacement. Finally, through modulation of physical and structural properties as well as leveraging our mechanistic understanding, we will optimize the parameters of the NHC to maximize desired soft tissue remodeling. If successful, this proposal will produce an improved off- the-shelf biostimulatory NHC with enhanced capacity to achieve natural tissue restoration outcomes as well as a mechanistic understanding of how to achieve soft tissue remodeling, thereby expanding the ability to treat patients and allowing scientists to engineer the next generation of biomaterials for tissue replacement.