Enhancement of stem cell regenerative properties by hydrogen sulfide: a novel wound dressing to augment stem cell therapies

摘要 尽管烧伤患者的护理有了显著改善，但仍有大约40，000名患者 每年在美国住院治疗严重烧伤，这种损伤与缓慢的 恢复和护理费用高。因为伤口愈合延迟会导致住院，并增加 感染，确定安全有效的治疗方法，促进伤口愈合，将有助于恢复 并改善烧伤患者的预后。成人脂肪干细胞在肿瘤治疗中的应用 烧伤创面再生皮肤作为一种有效的治疗方法越来越被人们所认识 来加速愈合和恢复然而，改善细胞向伤口递送和ADSC活力的方法， 并且需要修复功能来增加这种正在发展的再生疗法的功效。氢 硫化物（H2S）是一种气态生物介质，在各种组织中具有一系列作用。最近已经 表明H2S可以增加骨髓和脂肪来源的细胞的增殖、活力和功能， 干细胞，我们的初步数据证实了我们建议，局部H2S处理可以提高 ADSC治疗的再生特性和加速烧伤创面修复。然而，有效的应用 由于缺乏稳定的H2S供体或可以局部施用的诱导剂， 控制释放。一种生物相容的透明质酸（HA）基水凝胶，负载有缓慢的- 释放H2S供体，已被开发并用作敷料以增强非烧伤伤口愈合。此外，A 已经开发了具有包封的MSC的HA-水凝胶。在该项目中，双负载HA基水凝胶， 将开发含有H2S供体和ADSC两者的ADSC，并将其作为敷料应用于烧伤伤口。我们 假设将双重负载ADSC/H2S释放敷料应用于烧伤伤口将加速 通过H2S对ADSC存活、增殖和刺激ADSC的营养因子的产生的影响而愈合 愈合反应。这将通过以下目标进行测试：1）展示ADSC的改进 使用双负载ADSC-H2S释放伤口敷料的H2S伤口治疗在重度 损伤和自体移植。2)为了表征H2S对ADSC性能和功能的影响， 促进伤口愈合，在正常和缺氧条件下（缺血性伤口环境模型）; 3） 证明H2S增加人ADSC用于治疗烧伤伤口的治疗功效。这 该项目不仅将确定一种新的伤口敷料，以改善愈合，但它也将建立H2S作为 治疗，以增强用于治疗烧伤和其他疾病的再生干细胞疗法，并将 提供H2S对ADSC生物学调节的见解。

Abstract Despite significant improvements in the care of burn patients, approximately 40,000 patients are hospitalized yearly in the United States for the treatment of severe burns, an injury associated with slow recovery and high costs of care. Because delayed wound healing prolongs hospitalization and increases risk of infection, identification of safe and effective treatments that promote wound healing would facilitate recovery and improve outcomes for burn patients. The application of adult adipose-derived stem cells (ADSC) to regenerate skin in burn wounds is becoming increasingly recognized for its potential as an effective treatment to accelerate healing and recovery. However, methods to improve cell delivery to wounds, and ADSC viability and reparative functions are needed to increase the efficacy of this developing regenerative therapy. Hydrogen sulfide (H2S) is a gaseous biological mediator with a range of effects in various tissues. Recently it has been shown that H2S can increase the proliferation, viability and functions of bone marrow- and adipose-derived stem cells, confirmed by our preliminary data. We propose that local H2S treatment can enhance the regenerative properties of ADSC therapy and accelerate burn wound repair. However, the effective application of H2S to wounds is challenging due to a lack of stable H2S donors or inducing agents that can be topically delivered with controlled release. A biocompatible hyaluronic acid (HA)-based hydrogel, loaded with a slow- release H2S donor, has been developed and used as a dressing to enhance non-burn wound healing. Further, a HA-hydrogel with encapsulated MSC has been developed. In this project, a dual-loaded HA-based hydrogel, containing both an H2S donor and ADSC, will be developed and applied to burn wounds as a dressing. We hypothesize that application of a dual-loaded ADSC/H2S-releasing dressing to burn wounds will accelerate healing through effects of H2S on ADSC survival, proliferation and production of trophic factors that stimulate healing responses. This will be tested through the following aims: 1) To demonstrate improvement of ADSC wound therapy by H2S using dual-loaded ADSC-H2S releasing wound dressings in an ovine model of severe injury and autologous grafting.; 2) To characterize the effects of H2S on ADSC properties and functions that promote wound healing, under normal and hypoxic conditions (model of ischemic wound environment); 3) To demonstrate that H2S increases therapeutic efficacy of human ADSC for the treatment of burn wounds. This project will not only identify a novel wound dressing to improve healing, but it will also establish H2S as a treatment to augment regenerative stem cell therapies for the treatment of burns and other diseases and will provide insight into regulation of ADSC biology by H2S.