Objective To investigate the possible mechanism of the fibroblasts inducing the vascularization of dermal substitute. Methods Fibroblasts were seeded on the surface of acellular dermal matrix and cultivated in vitro to construct the living dermal substitute. The release of interleukin 8 (IL 8) and transfonming growth factor β 1(TGF β 1) in culture supernatants were assayed by enzyme linked immunosorbent assay, the mRNA expression of acid fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) were detected by RT-PCR. Then, the living substtute was sutured to fullth ickness excised wound on BALBouml;C m ice, and the fate of fibroblast w as observed by using in situ hybridizat ion. Results Fibroblasts cultured on acellular dermalmat rix p ro liferated and reached a single2layer confluence. Fibroblasts could secret IL 28 (192. 3±15. 9) pgouml;m l and TGF-B1 (1. 105±0. 051) pgouml;m l. There w as the mRNA exparession of aFGF and bFGF. Fibroblasts still survived and proliferated 3 weeks after graft ing. Conclusion Pept ides secreted by fibroblasts and its survival after graft ing may be relat ive to the vascularizat ion of the dermal subst itute.
Objective To investigate the effectiveness of autogenous platelet-rich plasma (PRP) gel with acellular xenogeneic dermal matrix in the treatment of deep II degree burns. Methods From January 2007 to December 2009, 30 cases of deep II degree burns were treated. There were 19 males and 11 females with an average age of 42.5 years (range, 32-57 years).The burn area was 10% to 48% of total body surface area. The time from burn to hospitalization was 30 minutes to 8 hours. All patients were treated with tangential excision surgery, one side of the wounds were covered with autogenous PRP gel and acellular xenogeneic dermal matrix (PRP group), the other side of the wounds were covered with acellular xenogeneic dermal matrix only (control group). The heal ing rate, heal ing time, infection condition, and scar formation were observed. Results At 7 days after operation, the infection rate in PRP group (6.7%, 2/30) was significantly lower than that in control group (16.7%, 5/30, P lt; 0.05). The healing times were (18 ± 4) days and (22 ± 4) days respectively in PRP group and control group, showing significant difference (P lt; 0.05). The healing rates at 14 days and 21 days were 75% ± 7% and 88% ± 5% in PRP group, were 62% ± 15% and 73% ± 7% in control group, showing significant difference (P lt; 0.05). RPR group was superior to control group in elasticity, color, appearance, softness, scar formation, and heal ing qual ity. Conclusion Autogenous PRP gel with acellular xenogeneic dermal matrix can accelerate the wound healing of deep II degree burns as well as alleviate the scar proliferation.
Objective To choose the best procedure on preparation of acellularbovine pericardium (ABP) guided bone regeneration (GBR) material. Methods The BP was decellularized with 0.25% Trypsin+0.5% Triton X-100. The acellular bovine pericardiums (ABPs) were treated with phosphatebuffered saline(PBS) (group A), 95% glycerol (group B), EDAC (group C), and EDAC and 95% glycerol (group D) respectively. The treated ABPs were implanted subcutaneously in the back of SD rats respectively at random and no material was implanted as control. Seven rats were sacrificed at 2 weeks, twelve at 4 weeks, twelve at 8 weeks, seven at 16 weeks. Local reaction was studied grossly. The amount of antigen presenting cell (APC) and the percentage of ABP degeneration were reckoned by images analysis system. Results The ABPs were replaced by fibroblasts completely in group A at 8 weeks， in group C at 16 weeks, but only less than 50% till 16 weeks in groups B and D. In all groups, the depth of surrounding fibres attenuated timedependingly. The APC amount of the groups B and D was higher than that of the control group, and the ABP of the groups B and D degraded partly at 16 weeks. Conclusion The ABP treated with EDAC can be replaced by the surrounding tissues and has good biocompatibility.
ObjectiveTo evaluate the effectiveness of acellular dermal matrix (ADM) with autologous buccal micro mucosa and micro skin graft in vaginoplasty. MethodsA retrospective analysis was made on the clinical data of 67 patients with vaginal agenesis treated between July 2006 and June 2013. ADM and mixed particles were used in 20 cases (ADM group) and mixed particles graft in 47 cases (control group) in vaginoplasty. There was no significant difference in age between 2 groups (t=0.233, P=0.816). The depth, diameter, and volume of neovagina, epithelization time, stent needing time, and female sexual function index (FSFI) score were compared between 2 groups. ResultsThere was no significant difference in operation time and amount of bleeding between 2 groups (t=-1.922, P=0.059; t=0.398, P=0.692). The patients were followed up 11-38 months (mean, 16.08 months). Fifteen cases in ADM group and 29 cases in control group had sexual life after operation. Bleeding after operation occurred in 6 cases (2 in ADM group and 4 in control group). No stenosis was observed. Difference in epithelization time was not statistically significant (t=-1.938, P=0.057). However, the stent needing time of ADM group was significantly shorter than that of control group (t=7.020, P=0.000). The neovagina was ideal in wetness degree, smoothness, flexibility, and hairlessness during follow-up. The depth, diameter, and volume of vagina had no significant difference between 2 groups (P>0.05) at last follow-up, which were close to normal vagina. The other patients had normal sexual function except 1 patient whose FSFI score was less than 23; no statistically significant difference was found in FSFI score between 2 groups (P>0.05). ConclusionOn the basis of mixed particles grafting, the ADM could improve trestle structure for resisting contracture. The effectiveness is better than merely mixed particles graft. The procedure has satisfactory anatomical and functional results.
OBJECTIVE: To observe the clinical effect of acellular allogenic dermis with split-thickness autogenous skin graft for coverage of wound. METHODS: Acellular allogenic dermis with split-thickness autogenous skin graft was used to repair 34 wounds of head, neck, trunk and extremities. The area of wounds was from 5 cm x 10 cm to 12 cm x 19 cm. Out of 34 wounds, there were 2 due to old granulation, 4 due to excision of giant pigmented nevus, 6 due to excision of capillary hemangioma of skin and 22 due to excision of scar. RESULTS: All grafts survived and had the smooth surface without obvious pigmentation and with slight wound contraction. CONCLUSION: Acellular allogenic dermis with autologous epithelium for coverage of various wounds is an ideal procedure.
Objective To explore the shortterm clinical effects of complex transplantation among the acellular dermal matrix(ADM) of heterogenic or heterocatal and autogenic split on the burnt wound as to find out a permanent substitution for the treatment on full skin thickness defect without scar. Methods Two kinds of ADM were used on the 18 patients with full thicknessburn wound through complex transplantation with autogenic splits. The patients with medialthickness autograft was used as control group. Survival rate was obtained 2 weeks after operation; contraction rate and the scores of Vancouver burn scale were obtained 8 weeks after operation. Results No significant difference was observed in survival rate among the three groups 2 weeks after operation(P＞0.05); no significant difference was observed in contraction rate of autografts and scores of Vancouver burn scale among the three groups 8 weeks after operation(P＞0.05). Conclusion ADM of heterogenic and ADM of heterocatal have similar effect on the reconstruction of skin, so the piglet ADM made in this way could be used as a substitution.
In the past fifty more years, many research results have been achieved in the field of artificial esophagus which has been a major subject of surgical study on esophagus. Unfortunately,a very satisfactory artificial esophagus has not been found due to lack of proper artificial materials and problems of postoperative complications which results in great hindrance to applying them to clinical purpose. The current research focuses on artificial esophaguses constructed with acellular matrix as well as constructed through tissue engineering,furthermore,how to prevent and cure postoperative complications is still the main difficulty. This paper gives an overview of the recent study results,points in dispute, present status of research and the recent advances, and an overview to the future of artificial esophagus.
Objective To study the migration of Schwann cells from the nerve autograft in the acellular nerve allograft of the rats in vivo. Mehtods The sciatic nerves (20 mm long) of the SD rats were harvested and prepared for the acellular nerve grafts by the chemical extraction. Then, they were observed by the gross view, HE staining, and Antilamininstaining, respectively. Another 32 female SD rats weighing 250-300 g were obtained for the study. A 2-mm-long nerve autograft was interposed between the two 10-mm-long nerve allografts to form a 22-mm-long composite. Then, the composite was placed in the muscle space, together with a sole 22-mm-long nerve allograftas a control. They were harvested at 5，10，15 and 20 days, respectively, and were then given the HE staining and the S-100 staining. Results The acellular nerve graft was semitransparent under the gross view. HE staining showed that no cell was observed within the nerve graft. Anti-laminin staining showed that the basal membrane was partially interrupted, with a positive result (dark brown). All the nerve grafts in both the groups exhibited the existenceof the cells. The S-100 positive cells were observed from the 15th day at the far ends of the two allografts of the composite; however, there were no suchcells observed within the sole nerve allograft. Conclusion Schwann cells from the sciatic nerves (2 mm- long) of the rats can migrate in the acellular nerve allograft to the far ends of the neighboring 10-mm-long nerve allografts at 15 days after operation, which offers the theoretical basis forthe repair of the longrange nerve defect by the composite of the acellular nerve allografts with the interposed nerve autograft.
Objective To develop a new small-caliber vascular xenograft and evaluate the feasibility of xenogenic artery for coronary artery bypass grafting. Methods Canine carotid arteries were decellularized by detergent and enzymatic extraction. All decellularized xenografts were randomly divided into two groups. Heparin-linked group （n=24）： grafts were then covalently linked with heparin. Non-heparin-linked group （n=24）： as control. Xenografts in two groups were implanted in rabbits＇ left and right carotid artery respectively as bypass grafts. Graft patency was checked by ultrasonography after 3 weeks, 3 and 6 months. Grafts were harvested after 3 and 6 months. Microscopic observation and immunohistochemical staining were performed. Results All the cells were removed while the extracellular matrix were well preserved observed. Heparin was successfully linked to the grafts through their whole thickness. There was no obstruction at both sides after implantation of the grafts, while less thrombus was found in the decellularized heparin-linked grafts than in the other side. Smooth muscle cells densely populated the graft wall and endothelial cells covered the lumen at 3 months after implantation. Conclusion Canine common carotid artery treated by detergent and enzymatic extraction and heparin linkage may be a new small-caliber vascular xenograft for coronary artery bypass grafting.
Objective To investigate the biocompatibility of acellular urinary bladder submucosa (AUBS). Methods The acellular collagen matrix of human urinary bladder submucosa was developed using freeze-thawed enzymatic treatment and freeze-drying technique. Human oral keratinocytes were cultured and seeded on AUBS at a density of 2×106/ml in vitro.The proliferation of the cells were observed. Pockets were created in the abdominal muscle wall of 18 SD rats. AUBS in size 1 cm×1 cm was implanted into the pocket. The grafts were observed by light microscope 3, 6, 10, 14, 21 and 28 days after operation. Results AUBSmainly consisted of collagen fibers with a three-dimensional network structure. After the oral keratinocytes were seeded, continous oral epithelium layer was formed on the surface of AUBS after 10 days in vitro. Histological observation of the grafted AUBS showed progressive cell infiltration at 6 days. New capillaries formed at 14 days. The collagen fibers arranged regularly at 28 days after implantation. Conclusion Freeze-dried AUBS may be used as a suitable scaffold for tissue regeneration, which can induce cell proliferation both in vivo and in vitro and has good biocompatibilty.