Objective To explore the possibilityof constructing tissue engineering muscles by combining allogeneic myoblasts with small instestinal submucosa(SIS) in rabbits.Methods A large number of purified myoblasts were obtained with multiprocedure digestion and repeated attachment method from skeletal muscles taken from extremities of immature rabbits which were born 7 days ago. The myoblasts were labeled with BrdU, and then combined with SIS to construct tissue engineering muscles. This kind of tissue engineering muscles were grafted into the gastrocnemius muscle defect (1.5 cm in length, 1.0 cmin width) of fifteen rabbits as the experimental group. The SIS was grafted into the same position in the control group. The rabbits were sacrificed 4, 6, 8 weeks after operation. The tissue engineering muscles were evaluated by macroscopic、histological and immunohistochemical observations, and by quantitative analysis of local immunocyte in the grafting site. Results Allogeneic myoblasts with SIS were combined perfectly in vitro. The SIS was connected tightly to surrounding skeletal muscles and inflammation response was obvious 4 weeks after grafting.The SIS began to break down and inflammation response became slight 6 and 8 weeks after operation. Compared with that of 8th week, the quantitative analysis oflocal immunocyte in 4th and 6th week in both experimental and control group hassignificance(Plt;0.05). Newly formed muscle tissues were found around SIS in the experimental group in 4th, 6th, and 8th week. Expression of BrdU and myosin immunohistochemical staining were positive in the experimental group and negative inthe control group.Conclusion Tissue engineering muscles of rabbits which are constructed by combining allogeneic myoblasts with SIS can survive and proliferate.
Objective to determine the modulus of elasticity (E) of small intestinal submucosa (SIS), a new biological graft material. Methods The longitudinal tensile testing was performed on 21 specimens of canine jejunum with the electronic material test machine. Results Stress (σ)strain (ε) data were obtained. It was found that the stress (σ)strain (ε) data fitted the expressionσ＝Kεα very well, the mean correlation coefficients R2 was0.991 6.Then the expression of the modulus of elasticity (E) of SIS was E=K1/ασ1-1/α. The mean values of α and K were 3.966 9 and 374.55，so E=4.3992σ0.75. Conclusion The modulus of elasticity was found to increase with increasing stress. The variations law is similar to that of the vessels. Furthermore when σ is 001333 MPa(100 mmHg),E is about 0.16 MPa, which is similar to that of the vessels.
Objective To evaluate the effect of hepatocyte growth factor(HGF) on intestinal permeability and bacterial translocation after small bowel transplantation in rats. Methods Twenty Wistar rats were as recptors and twenty SD rats as donors. After heterotopic intestinal grafting, cyclosporine A was administered at 6mg/kg·day intramuscularly for inhibiting rejection. The SD rats were divided into 2 groups(n=10). HGF was administered at 150 μg/kg·day (HGF group) and normal saline was administered at 150 μg/kg·day (controlgroup). Intestinal permeability and bacterial translocation to the mesenteric lymph nodes and portal vein were assessed at the 8th postoperative day. Results The lactulose and lactulose/ mannitol of control group (0.0931%±0.008 5% and 0.132± 0.021) were higher than those of normal reference value (0.015 0%±0.002 0% and 0.020±0.005)（Plt;0.05）. The lactulose and lactulose/ mannitol of HGF group (0.039 6%±0.009 0% and 0.056±0.013) were also higher than those of normal reference value（Plt;0.05）.The bacterial culture positive proportion of lymphaden in HGF group and control group were 10% and 60%, showing statistically significant difference（Plt;0.05）. The bacterial culture positive proportion of portal vein in HGF group and control group were 10% and 20% respectively（P＞0.05）. Conclusion HGF can decrease intestinal permeability and bacterial translocation from the lumen of the graft to the mesenteric lymph nodes,thus improve gut barrier function, may be of help to reduce the incidence of septic complications after intestinal grafting.
Objective To study the construction feasibility of a biodegradable artificial esophagus by the squamous epithelial cells and the myoblast cells seeded on the small intestinal submucosa(SIS) and to investigate the growth patternand angiogenesis of the co-cultured human embryonic squamous epithelial cells and the skeletal myoblasts in vivo. Methods The squamous epithelial cells and the myoblast cells were obtained from the 20-week aborted fetus. Both of their cellswere marked by 5-BrdU in vitro.The isolated cells were then seeded on the SIS and co-cultured in vitro for 24 hours, and then the compound of the cells and the SIS was transplanted into the subcutaneous tissue of the athymismus mice. The observation on the morphology and the cytokeratin AE3 and α-actin specified immunohistochemistry of the squamous epithelial cells and the myoblastcells was performed at each of the following time points: 3 days, 1 week, 2 weeks, and 3 weeks after transplantation. Results The morphological observation indicated that the cultured cells could penetrate into the small intestinal submucosa and form several-layered cell structures, and that the compound of the cells and the SIS could have angiogenesis within 2-3 weeks. The 5-BrdU specified immunohistochemical observation suggested that the cells growing in the small intestinal submucosa scaffold might be the cells transplanted.The cytokeratin AE3 specified and α-actin specified immunohistochemical studies demonstrated that the transplanted cells could differentiate in vivo. Conclusion It is possible to fabricate the framework of a biodegradable artificial esophagus with the epithelial cells and the myoblast cells seeded on the small intestinal submucosa.
Objective To compare the reparative effects between the acellular small intestinal submucosa andthe acellular amnion as dressings for traumatic skin defects. Methods Three full-thickness skin defects, which wereclose to the vertebral column of the pig, were created on both sides of the dorsum. The skin defects were randomlydivided into three groups. In each group, the following different materials were used to cover the skin defects: theacellular amnion in Group A, the acellular small intestinal submucosa (SIS) in Group B, and the physiological saline aguze in Group C (the control group). The specimens from the skin defects were harvested for a histological evaluation and for determination of the hydroxyproline content at 10 (2 pigs), 20 (2 pigs), and 30 days (3 pigs). We observed the healing process of the wound and its healing rate, counted the inflammatory cells, vasecular endothelial cells, and proliferating cells, and determined the hydroxyproline content. Results The acellular amnion in Group A and acellular SIS in Group B adhered to the wound tightly, but they did not adhere to the dressing; when the dressing was changed, the wound did not bleed. The saline gauze in Group C adhred to the wound tightly, but when the dressing was changed, the wound bled until 22 days after operation. Under the microscope, the collagen in the tissue below the epithelium was arranged more regularly and there were fewer cells concerned with inflammation in Groups A and B than in Group C at 10, 20, and 30 days after operation. At 10, 20, and 30 days after operation, the wound healing rate was greater in Groups A and B than in Group C, The number of the inflammatory cells and the proliferating cells were greater in Groupo C than in Groups A and B. There was a statistically significant difference (P lt; 0.05),At 20 and 30 days after operatin, the content of hydroxyproline was greater in Group c than in Group A and B. There was a statistically significant difference (P lt; 0.05). However, there was no statistically significant difference between Group A and Group B in the wound healing rate, the numbers of the inflammatory cells, vascular endothelial cells and prokiferating cells, and the content of hydroxyproline(P gt; 0.050). There was no statistically significant difference among the three groups in the number of the vascular endothelial cells. Conclusion Compared with Group C........
Objective To investigate effects of the autologous bone mesenchymal stem cells (MSCs) enriched by the small intestinal submucosa (SIS) film implantation on the myocardial structure, cardiac function, and compensator y circulation after myocardial infarction in the goats. Methods Sixteen black goats were selected and divided randomly into the control group (n=8)and the experimental group (n=8). The chronic myocardial infarction models were made by the ligation of the far end of the left anterior desc ending coronary artery. At the same time, MSCs were aspired from the thigh bone of the goats in the experimental group. MSCs were isolated by the centrifu gation through a percoll step gradient and purified by the plating culture and depletion of the non-adherent cells. Primary MSCs were cultured in the DMEM me dium supplemented with the fetal bovine serum in vitro. After that, the cultures were labeled by 5- BrdU. The active cells were transplanted into the SIS film. Six weeks after the ligation, the MSCs-SIS film was implanted by its being sutured onto the infarction area; whereas, the control group underwent a shamoperation. In both groups, echocardiographic measurements were performed before infarction, 6 weeks after infarction and 6 weeks after the MSC-collagen mplantion, respectively, to assess the myocardial structure and ca rdiac function. The left coronary artery angiography was performed with the digi tal subtraction angiography. Results In an assessment of the left ventricular function, at 6 weeks after operation, t he stroke volume and the ejection fraction of the control group and the experim ental group were 42.81±4.91, 37.06±4.75 ml and 59.20%±5.41%, 44.56%±4.23%, respectively (Plt;0.05). The enddisatolic volume and the endsystolic volume of the control group and the experimental group were 72.55±8.13, 83.31±8.61 ml and 29.75±5.98, 46.25±6.68 ml, respectively (Plt;0.05). The maximal velocity of peak E of contral group and experimental group were 54.8 5±6.35 cm/s and 43.14±4.81cm/s (Plt;0.01); and the maximal velocity of peak A o f control group and experimental grouop were 52.33±6.65 cm/s and 56.91±6.34 cm/s (Pgt;0.05). Echocowdiogr aphy sho wing a distinctly dilatation of left ventricle with the ventricular dyskinesia i n contral group, but without the ventricular dyskinesia in experimental group. T he selective-coronary evngiography revealed that the obvious compensatory circu l ation established between the anterior descending branch and the left circumflex branch in the experimental group. Conclusion Implantation of the autologus MSCs enriched by the SIS film can prevent dilatation of the left ventricular chamber and can improve the contractile ability of the myocardium, cardiac function, and collateral perfusion.
ObjectiveTo evaluate the effect of tissue engineered periosteum on the repair of large diaphysis defect in rabbit radius, and the effect of deproteinized bone (DPB) as supporting scaffolds of tissue engineering periosteum. MethodsBone marrow mesenchymal stem cells (BMSCs) were cultured from 1-month-old New Zealand Rabbit and osteogenetically induced into osteoblasts. Porcine small intestinal submucosa (SIS) scaffold was produced by decellular and a series mechanical and physiochemical procedures. Then tissue engineered periosteum was constructed by combining osteogenic BMSCs and SIS, and then the adhesion of cells to scaffolds was observed by scanning electron microscope (SEM). Fresh allogeneic bone was drilled and deproteinized as DPB scaffold. Tissue engineered periosteum/DPB complex was constructed by tissue engineered periosteum and DPB. Tissue engineered periosteum was "coat-like" package the DPB, and bundled with absorbable sutures. Forty-eight New Zealand white rabbits (4-month-old) were randomly divided into 4 groups (groups A, B, C, and D, n=12). The bone defect model of 3.5 cm in length in the left radius was created. Defect was repaired with tissue engineered periosteum in group A, with DPB in group B, with tissue engineered periosteum/DPB in group C; defect was untreated in group D. At 4, 8, and 12 weeks after operation, 4 rabbits in each group were observed by X-ray. At 8 weeks after operation, 4 rabbits of each group were randomly sacrificed for histological examination. ResultsSEM observation showed that abundant seeding cells adhered to tissue engineered periosteum. At 4, 8, and 12 weeks after operation, X-ray films showed the newly formed bone was much more in groups A and C than groups B and D. The X-ray film score were significantly higher in groups A and C than in groups B and D, in group A than in group C, and in group B than in group D (P<0.05). Histological staining indicated that there was a lot of newly formed bone in the defect space in group A, with abundant newly formed vessels and medullary cavity. While in group B, the defect space filled with the DPB, the degradation of DPB was not obvious. In group C, there was a lot of newly formed bone in the defect space, island-like DPB and obvious DPB degradation were seen in newly formed bone. In group D, the defect space only replaced by some connective tissue. ConclusionTissue engineered periosteum constructed by SIS and BMSCs has the feasibility to repair the large diaphysis defect in rabbit. DPB isn't an ideal support scaffold of tissue engineering periosteum, the supporting scaffolds of tissue engineered periosteum need further exploration.
Objective To review the development of researches on the stem cells and the tissue engineering technique used in the intestines. Methods We comprehensively reviewed the literature related to the stem cells and the tissue engineering technique used in the intestines, and summarized the conclusions made by the researches concerned. Results The researches on the stem cells and the tissue engineering technique used in the intestines were attractive topics in the recent years and obtained some developments, especially in the field dealing with the characteristics, proliferation and differentiation of the intestinal stem cells as well as the tissue engineering framework of the small intestinal submucosa in vivo. However, the markers for the differentiation of the intestinal stem cells were still a critical problem, which had not been solved yet, and besides, the researches on the intestinal tissue engineering were still in the initial stage. Conclusion There is a broad prospective application of the intestinal stem cells and the tissue engineering technique to the intestinal problem solution. Substantial achievements can be obtained in the treatment of the inflammatory bowel disease, inan exploration on the oncogenesis mechanism, and in the clinical application ofthe intestinal tissue engineering.
OBJECTIVE: To explore the expressive characteristics of epidermal growth factor (EGF) and its receptor (EGFR) in tissues of fetal and adult intestines. METHODS: The expression intensity and distribution of EGF and EGFR were detected with pathological and immunohistochemical methods in 6 specimens of adult (16-54 years) intestines and 18 specimens of fetal intestines with different gestational ages (13-31 weeks). RESULTS: Positive protein particles of EGF and EGFR could be detected in tissues of fetal and adult intestines. The protein expressions of EGF and EGFR were elevated progressively with the gestational age. EGF was mainly located in the cytoplasm and extracellular matrix of intestinal villus cells, endothelial cells and tunica serosa epithelial cells, while EGFR chiefly distributed in the cellular membrane of these cells. CONCLUSION: The endogenous EGF and EGFR might be involved in the intestinal development at embryonic stage, in the structural and functional maintenance at adult stage, and in the wound healing after injury.