Garcia-Gomez Ignacio, Gudehithlu Krishnamurthy P, Arruda Jose A L, Singh Ashok K
Ignacio Garcia-Gomez, Jose A L Arruda, Ashok K Singh, Division of Nephrology, Hektoen Institute of Medicine, Chicago, IL 60612, United States.
World J Stem Cells. 2015 Sep 26;7(8):1127-36. doi: 10.4252/wjsc.v7.i8.1127.
To investigate whether we could create natural autologous tissue patches in the subcutaneous space for organ repair.
We implanted the following three types of inert foreign bodies in the subcutaneous tissue of rats to produce autologous tissue patches of different geometries: (1) a large-sized polyvinyl tube (L = 25 mm, internal diameter = 7 mm) sealed at both ends by heat application for obtaining a large flat piece of tissue patch for organ repair; (2) a fine polyvinyl tubing (L = 25 mm, internal diameter = 3 mm) for creating cylindrically shaped grafts for vascular or nerve repair; and (3) a slurry of polydextran particle gel for inducing a bladder-like tissue. Implantation of inert materials was carried out by making a small incision on one or either side of the thoracic-lumbar region of rats. Subcutaneous pockets were created by blunt dissection around the incision into which the inert bodies were inserted (1 or 2 per rat). The incisions were closed with silk sutures, and the animals were allowed to recover. In case of the polydextran gel slurry 5 mL of the slurry was injected in the subcutaneous space using an 18 gauge needle. After implanting the foreign bodies a newly regenerated encapsulating tissue developed around the foreign bodies. The tissues were harvested after 4-42 d of implantation and studied by gross examination, histology, and histochemistry for organization, vascularity, and presence of mesenchymal stem cells (MSCs) (CD271+CD34+ cells).
Implanting a large cylindrically shaped polyvinyl tube resulted in a large flat sheet of tissue that could be tailored to a specific size and shape for use as a tissue patch for repairing large organs. Implanting a smaller sized polyvinyl tube yielded a cylindrical tissue that could be useful for repairing nerves and blood vessels. This type of patch could be obtained in different lengths by varying the length of the implanted tube. Implanting a suspension of inert polydextran suspension gave rise to a bladder-like tissue that could be potentially used for repairing heart valves. Histologically, the three different types of tissue patches generated were organized similarly, consisting of three layers, increasing in thickness until day 14. The inner layer in contact with the inert material was avascular; a middle layer that was highly vascular and filled with matrix, and an outer layer consisting of loose connective tissue. MSCs identified as CD271+CD34+ cells were present in the medial layer and around major blood vessels at day 4 but absent at later time points. The early-harvested tissues, endowed with MSCs, could be used for tissue repair, while the later-harvested tissues, being less vascular but thicker and tougher, could be used as filler tissue for cosmetic purposes.
An autologous, vascularized tissue patch of desired shape and size can be created in the subcutaneous space by implanting different types of inert bodies.
研究能否在皮下空间创建天然自体组织补片用于器官修复。
我们在大鼠皮下组织植入以下三种类型的惰性异物，以产生不同几何形状的自体组织补片：（1）一根大型聚乙烯管（长 = 25毫米，内径 = 7毫米），两端通过加热密封，以获取用于器官修复的大的扁平组织补片；（2）一根细聚乙烯管（长 = 25毫米，内径 = 3毫米），用于创建圆柱形移植物以修复血管或神经；（3）聚右旋糖酐颗粒凝胶浆液，用于诱导形成膀胱样组织。通过在大鼠胸腰段区域的一侧或两侧做一个小切口来植入惰性材料。通过在切口周围钝性分离创建皮下腔隙，将惰性物体插入其中（每只大鼠插入1个或2个）。切口用丝线缝合，让动物恢复。对于聚右旋糖酐凝胶浆液，使用18号针头将5毫升浆液注入皮下空间。植入异物后，在异物周围形成新再生的包裹组织。植入4 - 42天后收获组织，通过大体检查、组织学和组织化学研究其结构、血管分布以及间充质干细胞（MSCs，CD271+CD34+细胞）的存在情况。
植入大型圆柱形聚乙烯管产生一大片扁平组织，可根据特定尺寸和形状进行裁剪，用作修复大型器官的组织补片。植入较小尺寸的聚乙烯管产生圆柱形组织，可用于修复神经和血管。通过改变植入管的长度，可以获得不同长度的这种补片。植入惰性聚右旋糖酐悬浮液产生膀胱样组织，可能用于修复心脏瓣膜。组织学上，产生的三种不同类型的组织补片结构相似，由三层组成，直到第14天厚度增加。与惰性材料接触的内层无血管；中间层血管丰富且充满基质，外层由疏松结缔组织组成。在第4天，在内层和主要血管周围存在被鉴定为CD271+CD34+细胞的MSCs，但在随后的时间点不存在。早期收获的含有MSCs的组织可用于组织修复，而后期收获的组织血管较少但更厚更坚韧，可作为美容用途的填充组织。
通过植入不同类型的惰性物体，可以在皮下空间创建所需形状和大小的自体血管化组织补片。
