Objective To evaluate the effect of a combined cervicalexpanded skin flap in repairing cervical scar contracture deformity after burn injury. Methods From April 2001 to May 2003, 16 cases （10 males and 6 females）of scar contracture deformity in the cervix were treated withexpanded clavipectoral axis skin flap combined with reverse axis skin flap．The tissue expanders were embedded under the part containing cutaneous branches of transverse cervical artery in cervical segments and the second and/or the third perforating branch of internal thoracic artery for the first operation. Normal saline was injected regularly. The expanded clavipectoral skin flap and reverse axis skin flap with perforating branch of internal thoracic artery were designed,the scar in the cevix was loosed or dissected according to the size of the skinflaps, the skin flaps were transferred to cover the wound, and the contracture deformity in the cervix was corrected. The size of the flaps were 9 cm×5 cm-15 cm×7 cm. Results All skin flap survived. The function and appearance of the cervix was improved significantly after 6-30 months follow-up. However, venous return dysfunction in reverse perforating branch of internal thoracic artery occurred in 1 case, andblood circulation was improved after treatment. Conclusion Expanded clavipectoral axis skin flap combined with reverse axis skin flap can be used to repair scar contracture deformity in cervix, which lessen scar and abatethe chance to contract again.
Objective To develop a new kind of skin substitute, selective acellular porcine skin, to cover excised wounds in treatment of extensivedeep burns on the basis of controlled de-cell technique. Methods Partial thickness porcine skin was treated with 0.25% trypsin for 2 hours at 37℃ after crosslinked with glutaraldehyde, and then it was glued to a container with the edge embedded with glue. The skin was shaken in 0.5% SDS for 24 hours, and then washed before use. The selective acellular skin was used with micro-autografts on the dermal side to cover 2 surgically excised burn wounds in a patient. The recoveries of function and appearance were observed. Results Morphological observation showed that the treated porcine skin had an intact epithelial layer and an acellular dermis. After being used to cover burn wounds, its acellular dermis could serve as host dermal matrix, and its devitalized epithelial layer could prevent the dermis from drying. The devitalized epithelium wasfinally replaced by host epithelial cells, and the healed wounds could achieve good cosmetic and functional results. Conclusion Selective acellular porcine skin can be used as promising skin substitute to cover excised wounds.
ObjectiveTo comprehensively analyze the recent advancements in the field of mesenchymal stem cells (MSCs) derived exosomes (MSCs-exosomes) in tissue repair. MethodsThe literature about MSCs-exosomes in tissue repair was reviewed and analyzed. ResultsExosomes are biologically active microvesicles released from MSCs which are loaded with functional proteins, RNA, and microRNA. Exosomes can inhibit apoptosis, stimulate proliferation, alter cell phenotype in tissue repair of several diseases through cell-to-cell communication. ConclusionMSCs-exosomes is a novel source for the treatment of tissue repair. Further research of MSCs-exosomes biofunction, paracellular transport, and treatment mechanism will help the transform to clinical application.
Objective To review the latest research progress of full-thickness tissue engineered skin (FTTES), to thoroughly understand its current state of research and appl ication so as to lay a sol id foundation for developing new type FTTES and improving the qual ity of skin substitutes. Methods Domestical and international l iterature concerning FTTES in recent years was extensively reviewed and comprehensively analyzed. Results Some progress of FTTES had made in seedcells, scaffold materials and construction, and some therapeutic efficacy had also been achieved in cl inical appl ication. ButFTTES grafting successful rate was lower, and it had no complete skin structure and had not reached the requirements of cl inicalappl ication. Conclusion FTTES is an ideal skin substitute and has great development prospects. However, in seed cells, scaffold materials, construction and appl ications of FTTES, further studied is still needed.
Objective To review the research progress of mesenchymal stem cells (MSCs) in burn wound repair. Methods The recent literature about MSCs involved in burn wound repair and mechanism was extensively reviewed and analyzed. Results MSCs have the capacity of self-renew, rapid proliferation, differentiation and paracrine, and promote burn wound repair through differentiating into a series of skin wound cells and regulating wound microenvironment. Conclusion MSCs have great potentials in the burn field. However, the cell survival and outcome are also facing challenges from poor microenvironment of the burn wound.
Objective Endoplasmic reticulum stress (ERS) mediated apoptosis is one of the eukaryotic cellularapoptotic pathways, to investigate the potential role of ERS during myocardium apoptosis in rats with severe burninjury. Methods Sixty-four 7-week-old male Wistar rats, weighing 200-220 g, were randomly divided into 2 groups. Thirtypercentage of total body surface area full-thickness thermal injury was produced in 32 rats of burn group, while sham burn wasproduced in 32 rats of control group. The heart tissues were harvested from 8 rats in each group at 1, 4, 7, and 14 days after burnto observe the changes of myocardium ultrastructure with transmission electron microscope (TEM). Myocardium apoptosis wasdetected with TUNEL assay. The expressions of glucose regulated protein 78 (GRP 78), C/EBP-homologous protein (CHOP),and cleaved Caspase 12 in different pathways of ERS were analysed with Western blot. Results All rats survived during theexperiment. Apoptotic changes of cardiomyocytes were observed in burn group, and the apoptosis index in burn group wassignificantly higher than that in control group at each time point (P lt; 0.05), and it reached peak at 7 days after burn injury(P lt; 0.05). The expressions of myocardial GRP 78, CHOP, and cleaved Caspase 12 showed persistent elevation in burn group.The expressions of GRP 78 and cleaved Caspase 12 in burn group were significantly higher than those in control group at eachtime point (P lt; 0.05), while the expression of CHOP was higher than that in control group at the other time points (P lt; 0.05)except 1st day after burn injury. Conclusion ERS and CHOP, Caspase 12 mediated apoptotic pathway are activated inmyocardium after severe burn injury, and this may be one pathway of myocardium apoptosis.
Objective To prepare and study the biocompatibil ity of selectively decellular xenoskin which has the character of the lower antigen, continuous epidermis, and the dermal matrix without any cellular components. Methods The porcine skin was treated with glutaraldehyde solution, trypsin, and detergent solution TritonX-100 to prepare the selectivelydecellular xenoskin. The cytotoxicity was tested according to GB/T16886.5-2003 biological evaluation of medical devices for in vitro cytotoxicity, and the levels of cytotoxicity were evaluated with the United States Pharmacopeia. Subdermal implantation was tested according to GB/T16886.6-1997 biological evaluation of medical devices for local effects after implantation. Seventytwo mature Wistar rats were randomly assigned to groups A, B, and C (n=24). Three kinds of materials were implanted into subcutaneous of rats back. Selectively decellular xenoskin was transplanted into group A, fresh porcine skin was transplanted into group B, and allogeneic skin was transplanted into group C. The samples were collected to make the observation of gross and histology after 1, 2, 4, 8, 12, and 16 weeks. Results The cytotoxicity was proved to be first grade by biocompatibil ity test. The gross and histological observation of subdermal implantation: after implantation, the most severe inflammatory reactions were seen in group B which dispersion was very slow. Inflammatory reactions in groups A and C alleviated gradually. In groups A and C, there was an increased collagen fiber density and angiogenesis at late stage; the transplanted skin was gradually degraded and absorbed. In group B, no obvious degradation and absorption were observed. Conclusion Selectively decellular xenoskin, prepared with glutaraldehyde solution, trypsin, and detergent solution, possesses characteristics of integral skin structure andexcellent biocompatibil ity, so it can be used as a new type substitute to repair the burn wound.
Objective To summarize the research progress of biological characteristics and advantages of Wharton’s jelly-mesenchymal stem cells (WJ-MSCs). Methods The related l iterature on the biological characteristics of WJ-MSCs,umbil ical cord blood MSCs (UBMSCs) and bone marrow MSCs (BMSCs) was extensively reviewed and analyzed. Results A large number of MSCs which are able to self-repl icate, self-renew and have high prol iferation and multipotent differentiation can be isolated from the Wharton’s jelly of umbil ical cord. WJ-MSCs have many advantages in isolation time, isolation efficience, expansion time, passage capacity, expansion capacity when compared with UBMSCs and BMSCs. Conclusion WJ- MSCs have numerous advantages of convenient and abundant sources, relatively pure, non-ethical issues, and so on, which can be used for cell transplant therapy, gene therapy, and the ideal seed cells of building tissue engineered organ, so they provide new ideas for tissue regeneration repair and reconstruction.
Objective To establish a simple and efficient method to isolate and culture the umbilical vein vascular endothelial cells in canine. Methods Twelve umbilical cords [(13.0 ± 1.5) cm in length] were taken from 12 newborn pups of Beagles. And then the vascular endothelial cells were isolated from these umbilical cords digested by 1% collagenase type I for 5, 7, and 10 minutes respectively (4 umbilical cords in each group). After cultured, the vascular endothelial cells were identified by morphology, immunofluorescence, and flow cytometry. And the growth curvature of umbilical vein vascular endothelial cells was detected by MTT assay. Results Few vascular endothelial cells were collected at 5 and 10 minutes after digestion; many vascular endothelial cells were seen at 7 minutes, and became cobblestone with culture time, with a large nucleus; after passage, cell morphology had no obvious change. Fluorescence microscope results showed that positive von Willebrand factor (vWF) and CD31 cells were observed in most of cells. The flow cytometry test displayed that the positive cell rates of vWF and CD31 were 99.0% ± 0.7% and 98.0% ± 1.2%, respectively. The above results indicated that cultured cells were vascular endothelial cells. MTT assay showed that vascular endothelial cells proliferation increased significantly with culture time. Conclusion Enzyme digestion is a convenient method to isolate vascular endothelial cells from canine umbilical vein, and a large number of cells and high purity of cells can be obtained by the method.