| The experimental study of bone marrow mesenchymal stem cells on the healing of wound combined withlocal radiation injuryPh D Student: Guoping AiTutor: Prof.Yongping SuAbstractWound combined with radiation injury occur in nuclear attacks as well as in the nuclear accidents, especially caused by the depleted uranium weapons in modern war. The depletion and dysfunction of repairing cells numbers in wound are mainly responsible for the healing deficits. Thus, how to promote the healing processes of these injures are still one of the important issues in surgical fields. Recently, some methods to promote the healing of the wounds were reported. Such as the application of medicines, bio-dressings, cytokines, skin graft, transgene treatment, etc, but some shortcomings still existed. Cyctokines can promote the speed of healing. However, whether it can treat delayed wound remains unknown. Although the transgene method can overcome these shortcomings of applying cytokines, but it's hard to control the target direction and regulation of gene expression. The skin graft is the most effective treatment in the impaired wound, but it's very difficult to get enough allograft skin, the xenograft skin and artifical skin substitutes exist immune reactions. With the development of the stem cell engineering, we consider that we could use the characteristics of stem cells, which are highly proliferative and differentiated and could be easily obtained, to treat the skin wound combined with radiation injury which is caused by the depletion of repairing cells and dysfunction and try to develop a new treatment and method for curing woundhea1ing delay. It has been proposed that the stem cells will augrnent local repairor regeneration of bone, canilage or tCndon, bllt no reports abollt its aPPliCationin soft tissue injuries, not mention to aPply in wound combined radiation injwr.The present investigation was focused on the bone marrow mesenchymal stemcells (MSC) derived from mesoderm, Which can be induced to differentiate intorepairing cells in certain conditions, we directly trgnsPlanted MSC into thewounds in order to observe directly the effects of healing and to eXPlore themechanism of healing. The main resultS are as follows:l. TO iso1ate, cultUre, induce proliferation of hUInan and swine MSC. Thebest culture conditions in vitro fOr MSC groWth were to use the adhereni ceIlsin l2 hours, 7.5% fetal bovine serurn and the 6 xl0'/ml celIs density in theculture system. In this condition, cells could be maintalned for l4 passages andhad strong ability of proliferation and the duPlication time of cells was 3 to 4days. Cultured ce1ls had homogeneous spindle-shape.2. Cultured ce1ls were not fibroblast, endothelial cells and hematopoieticstem cells, and didn't exPress the anigens of collagen I, III and CD34. Theultrastructure of cells showed the characteristics of infantile cells. At the sametime, we successfully induced the culfored cel1s to differentiate into osteoblasts,chondrocytes and codried that cultured ce1ls were stem cells. It's the basicstep of MSC aPplication to repair bone and cedilage.3. The major mechanisms of the skin healing delay followed by local20Gy gamma-ray irradiation is the major factor of the depletion of stem cellsnumbers and depression of stem cells proliferation in wound.4. Therefore, MSC were directly transp1amed into the skin wound.Fluorescently labeled cells were visualized and photograPhed using afluorescent microscoPe. The cells of fluorescently labe1ed nuclei could beenseen in skin for a long time and could augment the healing of wound. The. III.numbers of fibroblasts and caPillary vessels were increased and the contents ofhydroxyProline and the synthesis of collagen wer eIhaed in MSC grouPs. TheHsis and secretion of collagen in fibroblaStS were increased under the eleCtrnAncroscope. It's very sure and sigIilfican tha tranSPlantaon of MSC couldpromote the heaiing of wound.5. The amnion matrix wt...
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