| Background:A variety of surgical intervention or infection may result in uterus damages, leading to regeneration disorder of endometria and subsequent intrauterine adhesion, amenorrhea and even infertility. Since no treatment is effective for damages of endometrium nowadays, studies have been trying to find out a new method to treat damages of endometrium. Due to the success in treating other diseases, tissue engineering may offer a new method for uterine functional reparation. In the current study, tissue engineering methods were used in the reparation of miniature pig uterine horns and we aim to evaluate the effect of collagen scaffolds, growth factors and bone mesenchymal stem cells in the regeneration of uterine endometrium, muscular cells and blood vessels.Chapter One:The effect of collagen scaffolds loaded with basic fibroblast growth factor, bone mesenchymal stem calls in the reparation of the new trauma of miniature pig uterine horns following full-thickness injuryObjective:To evaluate the effect of collagen scaffolds loaded with PBS, CBD-bFGF or BMSC in the reparation of the new trauma of miniature pig uterine horns after a 2 cm×1 cm full-thickness mechanical injury.Methods:Totally 39 female miniature pigs were randomly assigned to four groups, including spontaneous regeneration group (after uterine excision the defects were left open without reparation), collagen/PBS group (after uterine excision the defects were sutured with collagen membranes), collagen/CBD-bFGF group (after uterine excision the defects were sutured with collagen membranes loaded with CBD-bFGF) and collagen/BMSC group (after uterine excision the defects were sutured with collagen membranes loaded with BMSCs from male miniature pig). Each group was divided into unilateral damage group and bilateral damage group.90 days postoperatively, the animals were sacrificed and the uterine horns were prepared for the patency test and gross examination of adhesion, neovascularization and hydrometra. The uterine specimens were fixed with formalin. Sections of the damaged uterus were prepared for HE and immunohistochemistry staining.Results:(1) All of four groups showed severe extroversion of endometrial, especially for spontaneous regeneration group, almost all the operative field(90.3%) had extroversion. At the same time,55% of operative field in collagen/PBS group had extroversion 63.0% in CBD-bFGF group and 61.0% in collagen/BMSC group. (2) Comparing unilateral damage group with bilateral damage group, the three groups with treatment had higher healing rates for unilateral damage group than for bilateral damage group (25% vs.66.7% in Collagen/PBS group; 16.7% vs.36.7% in CBD-bFGF group; 37.5% vs.44.4% in Collagen/BMSC group). (3) Immunohistochemistry staining showed that the thickness of a-SMA positive area in collagen/PBS group, collagen/CBD-bFGF group and collagen/BMSC group were significantly higher than that in spontaneous regeneration group (P<0.05), however, there were no differences between the three groups. As for the thickness of endometrial, no difference was observed between the four groups (P>0.05).Conclusion:The full-thickness injury of miniature pig uterine horns was not a stable or valid animal model. We need to set up a new endometrial injury of miniature pig uterine horns model, and evaluate the effect of collagen scaffolds, growth factors and bone mesenchymal stem cells in the regeneration of uterine endometrium, muscular cells and blood vessels in this new anmimal model.Chapter Two:Study on the modeling a new endometrial injury of miniature pig uterine horns.Objective:To explor the feasibility of tissue engineering in repairing damaged endomerial for the clinical application, we need a stable and valid lager annimal model.Methods:Four sexual maturity miniature pigs were invovled in the trial. After the pigs were anesthetized, the abdomen was shaved. The uterine horns were exposed by an abdominal midline incision and a segment of approximately 2cm,3cm or 4cm in length and 1/2-2/3 of total circumference was cut in three sides. Each uterine horn contained 2 or 3 grafts according to the length of uterine horn. Separate the serosal layer and endometrium, then remove the endometrium and conbine the serosal layer with cut edge by continous suture.8 weeks and 12 weeks postoperatively, the animals were sacrificed and the uterine horns were prepared for the patency test and gross examination of adhesion, neovascularization and hydrometra. The uterine specimens were fixed with formalin. Sections of the damaged uterus were prepared for HE and immunohistochemistry staining.Results:(1) Compared with full-thickness injury, the model after improvement had less adhesion, and easy to apart. None everted or unclosed region were seen. The patency rate was 100%. (2) At the 8 weeks follow-up,2cm and 3cm incisions appeared regenerated endometrial, the thickness of endometrial, a-SMA positive area and and blood vessel density in two group was similar. (3) At the 12 weeks follow-up,2cm incisions had the best repairment, organization structure were closely resemble normal tissue.4cm incisions contractured and collapsed after 12 weeks, and tissue tructure appeared more organized with simple columar epitheliums. At the same time, muscle fibers were thin and discontinuous, lacing normal organization of uterus.Conclusion:A stable and valid endometrial injury model can be made through this surgucal approach. |
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