Matrix-reinforcing and cell-instructive smart hydrogel for cartilage preservation

腕关节损伤在现役和退伍军人群体中极为常见，无论是创伤还是磨损- 和眼泪。这些初始损伤损害了细胞周围的生物物理和生物化学环境， 其特征在于周围微环境的软化和促炎细胞因子的产生。 较软的细胞微环境导致软骨细胞的体积和形态变化，或 软骨细胞，并且促炎信号传导导致周围基质的持续降解。 结合起来，这些早期退行性变化导致异常细胞行为和恶性恶化过程， 导致软骨随着时间的推移而逐渐磨损并最终导致骨关节炎（OA）。OA是一项重大负担 对退伍军人人群，造成疼痛，不适，生活质量下降。阻止退化过程 在其进展的早期，通过特异性地修复细胞及其周围环境， 有效和创新的方法来预防或延迟OA的发作。因此，这一总体目标 本发明提出了一种利用新型透明质酸（HA）水凝胶系统来强化受损的软骨组织， 提供炎症抑制肽的持续呈递，所有这些目的都是为了防止 的OA。将通过以下具体目标对这一目标进行检验： 目的1：确定PCM强化对软骨细胞骨架组织的恢复作用， 机械传导首先，我们会发展一个医管局配方和应用的资料库，并在 受损的软骨组织，以实现3-4级PCM强化。然后，在软骨外植体培养模型中， 强化对软骨细胞体积调节、形态、细胞骨架组成和 将确定组织和机械转导性质并与健康细胞进行比较。 目的2：确定PCM强化和持续性炎症抑制的组合是否能预防 catelimination和恢复软骨细胞的稳态。HA将与细胞指导肽缀合， IL-1受体拮抗剂的活性序列（抑制炎症）。在软骨外植体中， 强化和炎症抑制肽，以及它们的组合，将在炎症细胞因子上进行测试 释放、矩阵分解和丢失以及矩阵合成。具体而言，将继续把重点放在恢复 基质合成和沉积（沉积）与降解（催化）的平衡。 目的3：评价增强抗炎肽联合应用的体内治疗效果 介绍软骨退化。在尤卡坦小型猪模型中，部分厚度缺损将用 强化或强化与抗炎肽的组合。功能多尺度生物力学 将在治疗后1个月和3个月评估检测和基质保留和质量，以表征 是否预防或减少了软骨退化的早期标志物。 这项研究将提高知识和理解的早期退行性变化的软骨细胞 及其周围基质，并直接开发了一种新的治疗策略，以机械稳定 软骨和传递细胞指导性的线索，以防止，甚至逆转，异常的软骨细胞的行为。 此外，所提出的工作的多尺度、多模态性质使用这些细胞级结果来驱动 组织功能和康复。这样的治疗在软骨损伤和 在退伍军人人群中进行骨关节炎治疗，改善活动水平和生活质量， 从而避免了全关节置换的需要。最后，提出了CDA-2研究结合 拟议的指导和培训计划，将使帕特尔博士获得大量的新技能和知识， 使他能够很好地过渡到一个成功的VA为基础的，独立的研究生涯。

Cartilage damage is extremely common in the active-duty and Veteran populations, both by trauma and wear- and-tear. These initial injuries compromise the biophysical and biochemical environment around cells, characterized by softening of the surrounding microenvironment and production of pro-inflammatory cytokines. The softer cellular microenvironment leads to volumetric and morphological changes of the cartilage cells, or chondrocytes, and the pro-inflammatory signaling leads to the continued degradation of the surrounding matrix. Combined, these early degenerative changes lead to aberrant cell behavior and a vicious deteriorative process, leading to progressive cartilage wear with time and culminating in osteoarthritis (OA). OA is a significant burden on the Veteran population, causing pain, discomfort, and reduced quality of life. Halting the degenerative process early in its progression, by specifically rehabilitating the cell and its surrounding environment, represents an impactful and innovative approach to preventing or delaying the onset of OA. Thus, the overarching goal of this proposal is to utilize a novel hyaluronic acid (HA) hydrogel system to both fortify damaged cartilage tissue and provide persistent presentation of inflammation-inhibiting peptides, all with the goal of preventing the progression of OA. This goal will be tested with the following specific aims: Aim 1: Determine the restorative effect of PCM fortification on chondrocyte cytoskeletal organization and mechano-transduction. First, a library of HA formulations and applications will be developed and tested on damaged cartilage tissue to achieve 3-4 levels of PCM fortification. Then, in a cartilage explant culture model, the impact of fortification on chondrocyte volume regulation, morphology, cytoskeletal composition and organization, and mechano-transductive properties will be determined and compared to healthy cells. Aim 2: Establish whether the combination of PCM fortification and persistent inflammatory inhibition prevents catabolism and restores chondrocyte homeostasis. HA will be conjugated with cell-instructive peptides that mimic an active sequence of IL-1 receptor antagonist (inhibits inflammation). In cartilage explants, the relative effects of fortification and inflammatory-inhibiting peptide, and their combination, will be tested on inflammatory cytokine release, matrix breakdown and loss, and matrix synthesis. Specifically, focus will be maintained on restoring the balance of matrix synthesis and deposition (anabolism) with degradation (catabolism). Aim 3: Evaluate the in vivo therapeutic effect of combined reinforcement and anti-inflammatory peptide presentation on cartilage deterioration. In a Yucatan minipig model, partial-thickness defects will be treated with fortification or a combination of fortification and anti-inflammatory peptide. Functional multi-scale biomechanical testing and matrix retention and quality will be assessed at 1- and 3-months post-treatment, to characterize whether early markers of cartilage deterioration were prevented or reduced. This research will enhance knowledge and understanding of the early degenerative changes to chondrocytes and their surrounding matrix, and directly develops a novel therapeutic strategy to mechanically stabilize cartilage and deliver cell-instructive cues to prevent, or even reverse, aberrant chondrocyte behavior. Furthermore, the multi-scale, multi-modal nature of the proposed work uses these cell-level outcomes to drive tissue-scale function and rehabilitation. Such a therapy would be monumental in the cartilage injury and osteoarthritis treatment in the Veteran population, improving activity levels and quality of life, and delaying or preventing the need for total joint replacement. Finally, the proposed CDA-2 research combined with the proposed mentoring and training plan, will allow Dr. Patel to acquire a plethora of new skills and knowledge, and position him well for a transition to a successful VA-based, independent research career.