Department of Biomedical Engineering, Yale University, New Haven CT 06511, United States; Vascular Biology and Therapeutics Program, Yale University, New Haven CT 06511, United States.
Department of Biomedical Engineering, Yale University, New Haven CT 06511, United States.
Biomaterials. 2018 Jul;169:61-71. doi: 10.1016/j.biomaterials.2018.03.049. Epub 2018 Mar 29.
Decellularized biologic scaffolds are gaining popularity over synthetic biomaterials as naturally derived materials capable of promoting improved healing. Nevertheless, the most widely used biologic material - acellular dermal matrix (ADM) - exhibits slow repopulation and remodeling, which prevents integration. Additionally, engineering control of these materials is limited because they require a natural source for their production. In the current report, we demonstrate the feasibility of using genetically engineered animals to create decellularized biologic scaffolds with favorable extracellular matrix (ECM) properties. Specifically, we utilized skin from thrombospondin (TSP)-2 KO mice to derive various decellularized products. Scanning electron microscopy and mechanical testing showed that TSP-2 KO ADM exhibited an altered structure and a reduction in elastic modulus and ultimate tensile strength, respectively. When a powdered form of KO ADM was implanted subcutaneously, it was able to promote enhanced vascularization over WT. Additionally, when implanted subcutaneously, intact slabs of KO ADM were populated by higher number of host cells when compared to WT. In vitro studies confirmed the promigratory properties of KO ADM. Specifically, degradation products released by pepsin digestion of KO ADM induced greater cell migration than WT. Moreover, cell-derived ECM from TSP-2 null fibroblasts was more permissive to fibroblast migration. Finally, ADMs were implanted in a diabetic wound model to examine their ability to accelerate wound healing. KO ADM exhibited enhanced remodeling and vascular maturation, indicative of efficient integration. Overall, we demonstrate that genetic manipulation enables engineered ECM-based materials with increased regenerative potential.
去细胞生物支架正逐渐取代合成生物材料，成为促进愈合的天然衍生材料。然而，最广泛使用的生物材料——去细胞真皮基质（ADM）——表现出缓慢的再血管化和重塑，这阻碍了其整合。此外，这些材料的工程控制受到限制，因为它们的生产需要天然来源。在本报告中，我们展示了利用基因工程动物来制造具有有利细胞外基质（ECM）特性的去细胞生物支架的可行性。具体来说，我们利用 TSP-2 KO 小鼠的皮肤来衍生各种去细胞产品。扫描电子显微镜和机械测试表明，TSP-2 KO ADM 的结构发生改变，弹性模量和极限拉伸强度分别降低。当 KO ADM 的粉末形式被皮下植入时，它能够促进血管生成。此外，当完整的 KO ADM 植入物被皮下植入时，与 WT 相比，有更多的宿主细胞定植。体外研究证实了 KO ADM 的促迁移特性。具体来说，胃蛋白酶消化 KO ADM 释放的降解产物诱导的细胞迁移比 WT 更多。此外，TSP-2 缺失成纤维细胞产生的细胞衍生 ECM 更有利于成纤维细胞迁移。最后，将 ADM 植入糖尿病创面模型中，以研究其促进创面愈合的能力。KO ADM 表现出增强的重塑和血管成熟，表明有效整合。总的来说，我们证明了基因操作使基于 ECM 的工程材料具有增强的再生潜力。
