From the Departments of Plastic and Reconstructive Surgery and Gastroenterology and Hepatology, Faculty of Medicine and Graduate School of Medicine, and Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine and Graduate School of Dental Medicine, Hokkaido University.
Plast Reconstr Surg. 2021 Jun 1;147(6):1342-1352. doi: 10.1097/PRS.0000000000007993.
Mesenchymal stem cells or their conditioned medium improve chronic wound healing, and their effect is enhanced by hypoxia. Diabetic foot ulcers are chronic wounds characterized by abnormal and delayed healing, which frequently require amputation. The authors evaluated the effect of topical application of conditioned medium from hypoxically cultured amnion-derived mesenchymal stem cells on wound healing in diabetic mice.
Amnion-derived mesenchymal stem cells were cultured under 21% oxygen to prepare normoxic conditioned medium and under 1% oxygen to prepare hypoxic conditioned medium. Hydrogels containing standard medium, normoxic conditioned medium, or hypoxic conditioned medium were topically applied to excisional wounds of mice with streptozotocin-induced diabetes. Ulcer tissues were harvested on day 9; immunohistochemical and quantitative polymerase chain reaction analyses were performed to analyze angiogenesis, inflammatory cell infiltration, and expression levels of inflammation-related genes.
Hypoxic conditioned medium significantly enhanced wound closure, increased capillary density and epithelization, and reduced macrophage infiltration. It also tended to reduce the infiltration of neutrophils and enhance the infiltration of regulatory T cells; it showed a tendency to downregulate the expression of the inflammation-related genes interleukin-1β, interleukin-6, chemokine ligand 1, and chemokine ligand 2. Normoxic conditioned medium exhibited similar effects, although they were of lesser magnitude than those of hypoxic conditioned medium.
Hydrogels containing hypoxically cultured, amnion-derived mesenchymal stem cell conditioned medium accelerated wound healing in diabetic mice by enhancing angiogenesis, accelerating epithelization, and suppressing inflammation. Therefore, topical application of amnion mesenchymal stem cell-derived hypoxic conditioned medium could be a novel treatment for diabetic foot ulcers.
间充质干细胞或其条件培养基可改善慢性伤口愈合，而缺氧可增强其作用。糖尿病足溃疡是一种慢性伤口，其特点是愈合异常和延迟，经常需要截肢。作者评估了缺氧培养的羊膜衍生间充质干细胞条件培养基局部应用于糖尿病小鼠伤口愈合的效果。
羊膜衍生间充质干细胞在 21%氧气下培养以制备常氧条件培养基，在 1%氧气下培养以制备低氧条件培养基。将含有标准培养基、常氧条件培养基或低氧条件培养基的水凝胶局部应用于链脲佐菌素诱导的糖尿病小鼠的切除伤口。在第 9 天收获溃疡组织；进行免疫组织化学和定量聚合酶链反应分析，以分析血管生成、炎症细胞浸润和炎症相关基因的表达水平。
低氧条件培养基显著促进伤口闭合，增加毛细血管密度和上皮化，并减少巨噬细胞浸润。它还倾向于减少中性粒细胞的浸润和增强调节性 T 细胞的浸润；它显示出下调炎症相关基因白细胞介素 1β、白细胞介素 6、趋化因子配体 1 和趋化因子配体 2 的表达的趋势。常氧条件培养基也表现出类似的效果，尽管其效果小于低氧条件培养基。
含有缺氧培养的羊膜衍生间充质干细胞条件培养基的水凝胶通过增强血管生成、加速上皮化和抑制炎症，加速了糖尿病小鼠的伤口愈合。因此，羊膜间充质干细胞衍生的低氧条件培养基的局部应用可能是糖尿病足溃疡的一种新的治疗方法。
