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加，预计60岁以上的老年人将占全球人口的20%。 到2050年的总人口。这些人口结构的变化将使医疗保健需求集中在那些更普遍的疾病上， 老人慢性伤口，如下肢静脉溃疡、压疮和糖尿病溃疡， 老年人口，甚至现在也是一个巨大的医疗负担。这些条件影响约6.5 每年有100万患者，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， 这些慢性伤口受到年龄相关因素的干扰，例如血流量减少、皮肤萎缩、 炎症和减少的生长因子反应。高复发率和对当前治疗的无效 表明需要改进的再生治疗，可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令人信服的组织修复手段， 愈合和软组织再生的动物模型。然而，治疗性干细胞移植的直观概念 并在组织损伤部位分化，并没有得到很好的支持， 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，如 分泌生物活性囊泡，包括外来体。因此，利用干细胞衍生的外泌体作为生物衍生的外泌体， 治疗，而不是提供短暂的干细胞来治疗慢性伤口，是一种诱人的方法。细胞外分泌 囊泡（EV），如外泌体，充满了有效的前修复蛋白和RNA货物，这两种细胞类型， 特异性，以及根据细胞环境差异产生和分泌。基于我们令人信服的 初步数据，这第一阶段的概念验证研究将证明，关键的离体环境线索可以调整， 干细胞衍生EV是促愈合的，且促愈合EV是有效的慢性伤口治疗剂。我们将实现 这些目标通过以下目的实现：1）操纵生物反应器环境以产生差异细胞外囊泡 2）在成纤维细胞、角质形成细胞和内皮细胞中EV介导的再生活性的体外测试，和 3)在慢性伤口愈合模型中促愈合EV的体内测试。第一阶段研究计划旨在 提供关键的概念验证数据，证明干细胞的生产条件和伤口愈合特性- 衍生的细胞外囊泡。这种潜在的治疗方法具有利用干细胞力量的独特优势 而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.