Tissue Engineering for the Treatment of Delayed Healing

描述(申请人提供)：一种更有效的慢性创面组织工程学方法可能需要替换表型改变的创面细胞，可能通过使用干细胞。利用绿色荧光蛋白(GFP)转基因小鼠和野生型小鼠，我们已经证明，输注GFP骨髓细胞可以导致创伤皮肤中血管、角质形成细胞和其他结构的产生。我们利用常规尾巴的切除伤口开发的一种新的延迟愈合模型将使我们能够扩展这些观察。与此同时，我们发现，局部应用自体骨髓来源的细胞可以显著促进未愈合的人类慢性伤口的愈合。我们提出了以下具体目标：1)利用GFP骨髓细胞和不同的骨髓细胞输送方法将未分离的骨髓细胞移植到延迟愈合的小鼠模型中；2)确定促进小鼠伤口愈合的骨髓细胞亚群。我们将评估未分离的骨髓，以及LIN和阳性的LIN骨髓细胞、间充质干细胞和造血干细胞，包括LIN-SCA和LIN-HO/10Rho/10细胞。3)评估骨髓来源细胞的局部输送情况。体外和体内研究将确定在凝血因子XIII交联型纤维蛋白凝胶中使用特定骨髓来源细胞的可行性；4)确定自体骨髓来源细胞能否纠正慢性伤口的异常细胞表型。我们将把特定的骨髓细胞亚群应用于无法愈合的人类伤口，并将确定伤口成纤维细胞是否恢复了愈合和正常表型。 这些研究将促进我们对如何重建伤口床以及是否有可能纠正未愈合伤口的异常细胞表型的理解。

DESCRIPTION (provided by applicant): A more effective tissue engineering approach to chronic wounds may require the replacement of phenotypically altered wound cells, possibly through the use of stem ceils. Using green fluorescent protein (GFP) transgenic and wild type mice, we have shown that infusion of GFP + marrow cells can result in the production of blood vessels, keratinocytes, and other structures in wounded skin. A new model of delayed healing we have developed using excisional wounds of routine tails will allow us to extend these observations. In parallel, we have found that non-healing human chronic wounds heal dramatically with the topical application of autologous bone marrow-derived cells. We propose the following specific aims: 1) to characterize the engraftment of unseparated marrow cells in a murine model of delayed healing using GFP - marrow cells and different methods of marrow cell delivery to wounds; 2) to determine the marrow cell subsets that accelerate healing in murine wounds. We will evaluate unseparated marrow, as well as Lin- and positive Lin+ marrow cells, mesenchymal stem cells, and hematopoietic stems cells, including Lin-Sca+ and Lin- Ho/l0Rho/10cells. 3) to assess the topical delivery of marrow-derived cells. In vitro and in vivo studies will determine the feasibility of this approach using specific marrow-derived cells in a Factor XIII cross-linked fibrin gel; 4) Determine whether autologous marrow-derived cells can correct the abnormal cellular phenotype of chronic wounds. We will apply specific subsets of marrow cells to non-healing human wounds and will determine whether healing and normal phenotype are restored in wound fibroblasts. These studies will advance our understanding of how to reconstitute the wound bed and whether it is possible to correct the abnormal cellular phenotype in non-healing wounds.