Role Of Polypropylene Mesh Coated With Silk Fibroin In Reconstruction On Rats With Abdominal Defect

Partâ… :Research on Polypropylene Modified by Silk FibroinObjective:To prepare polypropylene modified by silk fibroin under the ionic environment and to research on the mesh's physico-chemical property.Methods:To treat the polypropylene mesh under the ionic environment modified by the prepared solution of silk fibroin by 2%,and to detect the mesh's physico-chemical property by scanning electron microscope,infrared spectrum and Raman spectrum.Results:To treat the polypropylene mesh under the ionic environment full of gas of He₂, leads the hydrophobic surface of mesh to hydrophilism.Then we can prepare polypropylene modified by silk fibroin.Under the SEM,we found that pure polypropylene mesh without silk fibroin was smooth and glossy on its surface and albugineous coat of silk fibroin on the surface of mesh modified with silk fibroin.And we also found the absorption peak of a-helical conformation for silk fibroin on the surface of the polypropylene mesh by the infrared spectrum(1650,1537 and 1242 cm^-1)and Raman spectrum.Conclusions:Polypropylene mesh shows good hydrophilism under the ionic environment full of gas of He₂.And the longer time for treatment under ionic environment,the more profit would the mesh gain from madefaction,overlaying by solution of silk fibroin.The best time was tested to be 120 seconds.Partâ…¡:Research on the Animal Model of Abdominal DefectObjective:To build the animal model of abdominal defect.Methods:Ten male SD rats were chosen for the model.The rats were cut off a part of the abdominal muscles and tissues for 2*2 cm² through the paramedian incision and were raised for one month to form the defect.All the rats were executed in 30 days after the operations,and the defect of abdominal would be measured on them.Results:In this group,the general conditions on the all the rats,including basic temperatue,foodintake,were well.The basic temperatue ranged from 37.8℃to 38.5℃. Ecchymoma was found on three of them(30%) in day 2,day 2 and day 3 after the operation and was recovered in a week;and there were no other kinds of serious complications on the rats.The abdominal defect was measured as(2.15±0.04)*(2.09±0.02)cm² in one month after the operation.Conclusionsn:The method of cut offthe abdominal muscles to build the animal model of abdominal defect is ideal and executive.Partâ…¢:Role of Polypropylene Mesh Coated with Silk Fibroin in Reconstruction on Rats with Abdominal DefectObjective:To compare the curative effects between polypropylene mesh coated with or without silk fibroin and e-PTFE mesh in the treatment of abdominal defects.To explore the merits of polypropylene mesh coated with silk fibroin in promoting peritoneum healing, mesothelial cell hyperplasia,and decreasing related complications.Methods:Sixty-two male SD rats were chosen,divided randomly as follows:group one: polypropylene mesh coated with silk fibroin(n=20),group two:pure polypropylene mesh without silk fibroin(n=20),pure e-PTFE mesh(n=20).Firstly we made animal models of abdominal defects.We held repair operation on the rats with abdominal defects through abdominal cavity with 3 kinds of different meshes,polypropylene mesh coated with without silk fibroin,without silk fibroin and pure e-PTFE mesh for 2*2 cm².All the rats were executed in 3 days,7 days,14 days and 60 days after the operations,and histopathological examination and scanning electron microscopic examinations were performed on them.All complications such as death,local inflammation,intestinal fistula and intestinal obstruction were documented.And we measured the quality and quantity of the adherence between mesh and abdominal organs or tissues.Group four,leave two normal rats as controlled study,removed the anterior abdominal wall of muscles and peritonium,and histopathological examination,scanning electron microscopy were performed as controlled study.Results:In group one,polypropylene mesh coated with silk fibroin the experiment showed there was no obviously adherence on the meshes,and the area of the adherence on the mesh was calculated as(4.81±4.50)%,The mesothelial cell had grown on the silk fibroin in 3 days,and covered the mesh completely in 7 days.And from 14 days to 60 days, we found mesothelial cell,fat cell and blood capillary hyperplasia well.Histopathological examination showed there was no obvious granulation tissue and scar,and the peritonium membrane and mesothelial cell grow normally.The silk fibroin was not entirely absorbed and the remains showed good biocompatibility.In group two,pure polypropylene mesh, there were 5 rats died in 2,4,6,7,9 days after surgery,and all of them got serious adherence between polypropylene mesh with intestine,3 of them with intestinal fistula and 2 of them got intestinal obstruction.Nearly all rats got adherence in abdominal cavity between mesh with organs or tissues,and the area of the adherence on the mesh was calculated as(74.96±23.57)%.There was nearly no adherence in the group three,pure e-PTFE mesh,and the area of the adherence on the mesh was calculated as(2.26±1.61)%.There were significant statistically differences in these postoperative complications(P＜0.01) and adherence degree(P＜0.01) between the three groups by SPSS 16.0.Conclusions:Silk fibroin and polypropylene mesh coated with silk fibroin showed good biocompatibility.Polypropylene mesh coated with silk fibroin used in reconstruction of rats with abdominal defects can promote agglutination of mesothelial cells,repair of peritoneum,and decrease postoperative complications,such as local inflammation, intestinal fistula and intestinal obstruction.It may be a prospective biomaterial which can be used in clinical abdominal defect reconstruction.