Tuned stem cell extracellular vesicles as a novel chronic wound therapeutic

项目摘要 全球老年人口正在迅速增长，60岁以上的老年人口预计将占全球老年人口的20% 到2050年总人口。这些人口结构的变化将使医疗保健需求集中在那些在 老年人。慢性伤口，如静脉性小腿溃疡、压疮和糖尿病溃疡，在 人口老龄化，即使是现在也造成了巨大的医疗负担。这些情况影响了大约6.5 每年有100万名患者，医疗保健系统的成本超过250亿美元。很少发生在年轻人身上，治愈 这些慢性创面被与年龄有关的因素混淆，如血流量减少，真皮萎缩，增加 炎症和生长因子反应减少。复发率高，对目前的治疗无效 表明需要改进的再生疗法，以克服许多与年龄相关的缺陷 伤口愈合过程。干细胞疗法代表了一种引人注目的组织修复方法，并已证明是一种创伤。 动物模型中的愈合和软组织再生。然而，治疗性干细胞移植的直观概念 在组织损伤部位的分化没有得到很好的支持，因为随着时间的推移，细胞数量很少 体内应用部位。这表明它们的作用机制是通过旁分泌方式发生的，例如 分泌具有生物活性的囊泡，包括外周小体。因此，利用干细胞来源的外切体作为生物来源的 治疗，而不是输送瞬时干细胞来治疗慢性伤口，是一种诱人的方法。分泌型胞外 囊泡(EV)，如外体，充满了强大的促修复蛋白和RNA货物，这两种细胞类型- 根据细胞环境的不同，特定的以及不同的产生和分泌。基于我们令人信服的 初步数据，这项I阶段概念验证研究将证明关键的体外环境线索可以调整 干细胞来源的EVS是促进愈合的，并且促进愈合的EVS是一种有效的慢性伤口治疗方法。我们将实现 这些目标的目的如下：1)操纵生物反应器环境以产生不同的胞外囊泡 包装，2)体外检测EV介导的成纤维细胞、角质形成细胞和内皮细胞的再生活性，以及 3)慢性创面愈合模型中促愈合电动车的体内测试。该第一阶段研究计划旨在 提供关键的概念验证数据，展示干细胞的制造条件和伤口愈合特性- 衍生的细胞外小泡。这种潜在的治疗方法具有独特的优势，即利用干细胞的力量 不需要在体内使用复杂的细胞疗法。

Project Summary The elderly population is rapidly increasing worldwide and those over 60 years old are expected to comprise 20% of the total population by 2050. These demographic changes will focus healthcare needs on those conditions more prevalent in the elderly. Chronic wounds, such as venous leg ulcers, pressure ulcers and diabetic ulcers are over-represented in the elderly population and even now present a significant healthcare burden. These conditions impact approximately 6.5 million patients annually with a cost to the health care system of over $25B. Rarely occurring in the young, the healing of these chronic wounds is confounded by age-related factors such as reduced blood flow, dermal atrophy, increased inflammation and reduced growth factor responses. The high recurrence rate and failure to respond to current therapies indicates the need for improved regenerative therapeutics that can overcome many of the age-associated defects in the wound healing process. Stem cell therapies represent a compelling means of tissue repair and have demonstrated wound healing and soft tissue regeneration in animal models. However, the intuitive concept that therapeutic stem cells engraft and differentiate at sites of tissue damage is not well supported given the low numbers of cells retained over time at application sites in vivo. This suggests that their mechanisms of action occur through paracrine modalities such as secretion of bioactive vesicles, including exosomes. Hence, exploiting stem cell-derived exosomes as a biologic-derived therapy, rather than delivering transient stem cells to treat chronic wounds, is an enticing approach. Secreted extracellular vesicles (EVs), such as exosomes, are packed with potent pro-repair proteins and RNA cargos that are both cell type- specific, as well as, differentially produced and secreted according to the cellular environment. Based on our compelling preliminary data, this Phase I proof-of-concept study will demonstrate that critical ex vivo environmental cues can tune stem cell-derived EVs to be pro-healing and that pro-healing EVs are a valid chronic wound therapeutic. We will achieve these goals by the following Aims: 1) manipulate the bioreactor environment to generate differential extracellular vesicle packaging, 2) in vitro testing of EV-mediated regenerative activities in fibroblasts, keratinocytes and endothelial cells, and 3) in vivo testing of pro-healing EVs in chronic wound healing models. This Phase I research program is designed to provide critical proof-of-concept data demonstrating manufacturing conditions and wound healing properties of stem cell- derived extracellular vesicles. This potential therapeutic has the unique advantage of harnessing the power of stem cells without the need for utilizing complex cell therapies in vivo.