Regenerative Lipid Mediators for the Management of Severe Burn Wounds

摘要 严重烧伤的治疗依赖于自体皮肤移植，但由于供体部位的限制，自体皮肤移植受到限制。 无法获得和严重的并存。目前的治疗方法不能消除实质性的治愈。 严重烧伤的缺陷，突显了对更有效治疗的迫切需要。我们的长期目标是 为严重烧伤开发更好的治疗方法。间充质干细胞(MSCs)具有再生能力 烧伤的伤口。脂肪组织来源的微血管片段(MVF)是天然的血管生成单位，是一种 来源丰富的MSCs，内皮细胞，血管周围细胞和脂肪细胞是重建烧伤所必需的 皮肤受损。MVF为MSCs提供了更好的利基，最大限度地提高了MSC的再生能力。MVF也是 很容易从通过微创吸脂收集的脂肪组织中分离出来。我们已经鉴定出再生脂质 促进MSC或MVF增殖、存活和产生生长因子的介体(ReLim)，以及 促进组织再生。ReLiM1恢复了受损的血管形成和愈合。然而，ReLim拥有 创面半衰期短，限制了其在烧伤愈合和骨髓间充质干细胞功能化方面的作用。要解决这个问题 问题是，我们开发了一种水凝胶，可以在烧伤创面保持Relim水平。Relim版本是 由可生物降解、无毒的氨基酸基聚(酯酰胺)蛋白模拟水凝胶维持 聚合物(AA-豌豆)。缓释微球与AA-PEA-水凝胶(凝胶)骨架的整合 促进愈合，促进MSC/MVF功能。我们假设持续释放的ReLim 复合凝胶支架可直接促进严重烧伤创面愈合，保护和引导MVF 再生功能。我们的目标是开发可提供ReLiM的再浸渍凝胶，并提供 用于治疗严重烧伤并保护和引导MVF再生功能的支架，以更好地愈合AS 以及破译发生这种情况的机制。目标1.我们将把AGel开发为可持续发展 Relim释放和TO 1B)提供用于皮肤细胞归巢的最佳Relim释放仿生基质， 血管化和再上皮化，以及减少疤痕和增加伤口破裂 力量。目标2.2a)我们将开发一种结构，整合未培养的自体MVF，持续 释放ReLim和凝胶支架，最大限度地促进深度烧伤的愈合。我们预测，取得的成就 构建、保护和引导MVF功能。我们将在体外使用人类MVF验证结果，以获得更好的结果 翻译价值。2B)我们将破译最好的MVF-Relim-agel的疗效机制。影响：这 项目将提供1)Relim-agel敷料，提供ReLim，并提供矩阵和覆盖 高效愈合，2)携带Relim和MVF的凝胶基质，保护和引导未培养的MVF获得更多 有效的治疗，以及3)潜在的机械知识。这些再生的脂质介体 不需要或最少需要移植物供者的功能化敷料是有希望的辅助治疗 以克服目前用于治疗严重烧伤的移植方法或皮肤替代品的缺点。

ABSTRACT The treatment of severe burns relies on autologous skin grafts, which are limited due to donor-site unavailability and substantial comorbidities. Current therapies are unable to eliminate substantial healing defects in severe burns, underscoring the urgent needs of more effective therapies. Our long-term goals are to develop better therapies for severe burns. Mesenchymal stem cells (MSCs) possess regenerative power for burn wounds. Adipose-tissue derived microvascular fragments (MVFs) are native vascularization units and a rich source of the MSCs, endothelial cells, perivascular cells, and adipocytes essential in rebuilding burn- destroyed skin. MVFs provide a better niche for MSCs, maximizing MSC regenerative power. MVFs are also easily isolated from fat tissue collected via minimally invasive liposuction. We have identified regenerative lipid mediators (ReLiMs) that increase MSC or MVF proliferation, survival, and production of growth factors, and promote tissue regeneration. ReLiM1 restored impaired vascularization and healing. However, ReLiMs have short half-lives in wounds, limiting their utility for healing burns and functionalizing MSCs. To address this problem, we developed a hydrogel that can sustain ReLiM levels in burn wounds. ReLiM release was sustained from the hydrogel of biodegradable, non-toxic amino acid-based poly(ester amide) protein-mimic polymers (AA-PEAs). The integration of a sustained-release ReLiM with an AA-PEA-hydrogel (Agel) matrix accelerated healing and promoted MSC/MVF functions. We hypothesize that sustained release ReLiMs combined with Agel scaffolds directly promote healing of severe burns and protect and guide MVF regenerative functions. Our objective is to develop ReLiM-impregnated Agels that deliver ReLiMs and provide scaffolds for healing severe burns and protecting and guiding MVF regenerative functions for better healing as well as to decipher the mechanisms via which this occurs. Aim 1. We will develop the Agel to 1A) sustain ReLiM release and to 1B) provide an optimal ReLiM-releasing biomimetic matrix for skin cell homing, vascularization, and re-epithelization, as well as for the reduction of scarring and increasing wound breaking strength. Aim 2. 2A) We will develop a construct that integrates uncultured autologous MVFs, sustained release ReLiMs, and Agel scaffolds to maximize the healing of deep burns. We predict that the achieved construct protects and guides MVF functions. We will verify results using human MVFs in vitro for better translational value. 2B) We will decipher mechanisms for efficacy of the best MVF-ReLiM-Agel. Impact: This project will provide 1) a ReLiM-Agel dressing that delivers ReLiMs and provides a matrix and covering for efficient healing, 2) a ReLiM- and MVF-carrying Agel matrix that protects and guides uncultured MVFs for more efficient healing, and 3) the underlying mechanistic knowledge. These regenerative lipid mediator functionalized dressings with nonexistent or minimal graft-donor requirements are promising adjuvant therapy to overcome the drawbacks of grafting methods or skin substitutes currently used to treat severe burns.