Animal Experimental Study On The Treatment Of Abdominal Wall Hernia With Adipose-derived Stem Cells Composite Biological Mesh

Purposes:Abdominal wall hernia(inguinal hernia,umbilical hernia,incisional hernia,etc.)is a common clinical disease,which is essentially a soft tissue defect of the abdominal wall.The application of mesh to treat abdominal wall hernia has become routine.There are two types of meshes:synthetic mesh and biological mesh.Biological mesh is an extracellular matrix component obtained by decellularizing human or animal tissue,which has a certain mechanical strength and can be remodeled by the host after a period of time after transplantation.Due to the advantages of capacitance,anti-infection,anti-adhesion,and complete degradation in vivo,it has become a research star of hernia repair materials.However,it is clinically found that the recurrence rate of abdominal wall hernia after the application of biological mesh is relatively high.In addition to the repair technology,the reason is also related to the insufficient strength of the biological mesh and the rapid absorption and degradation.In clinical work,adipose-derived stem cells(ADSCs)combined with biological scaffolds have been implanted into the body to treat bone defects,cartilage defects,nerve repair,and reconstruction after mastectomy.Study on the construction of hernia patch with bioscaffold.This study envisages using adipose-derived mesenchymal stem cells as "seeds" and small intestinal submucosa(SIS)as biomaterial scaffolds.The combination of the two can induce the differentiation of adipose-derived mesenchymal stem cells into fibroblasts,realize the "reprocessing" of biological patches,and improve physicochemical properties of the mesh(strength,degradation rate),making it more beneficial for the treatment of abdominal wall hernia.Methods:(1)Isolation and culture of rat ADSCs;immunophenotype identification by flow cytometry.(2)ADSCs were cultured to induce differentiation towards lipogenesis,osteogenesis and chondrogenesis(3)Clarify the observation time point of each index:transfect Luciferase lentivirus with the fourth generation ADSCs,and select ADSCs stably expressing Luciferase with puromycin.(4)To establish abdominal wall hernia model in rats,ADSCs composite with SIS repaired abdominal wall hernia in rats was used as the experimental group,and SIS repair alone was used as the control group,and the rats were killed on day 14 and the tissue in the repair area was removed.Evaluation respectively:1)Carry out the tensile strength test to clarify the difference in tissue strength in the repaired area.2)Immunohistochemistry and Western blot were used to detect the changes in the expression of vascular endothelial cell surface markers CD31,type I and type III collagen.Results:(1)ADSCs were transmitted once every 3 days,1 passage for 3 passages,and could be stably transmitted for more than 10 generations,and there was no significant difference between generations.Under the microscope,the cell morphology was gradually homogeneous,similar to that of fibroblasts,with a long shuttle shape or spindle shape;the cell surface molecules were highly expressed in CD29 and CD90 by flow cytometry.(2)ADSCs have the characteristics of mesenchymal stem cells and can differentiate into adipose tissue,bone tissue and cartilage tissue.(3)IVS Spectrum small animal in vivo optical imaging system was used to understand the time point of ADSCs survival and natural death in vivo.In vivo survival of Luciferase-expressing ADSCs was significantly lower at 14 days post-operatively.Therefore,postoperative day 14 was chosen as the observation point for this experiment.(4)On the 14th day after operation,the tensile strength of the experimental group increased slightly,but there was no statistical difference compared with the tensile strength of the tissue around the mesh in the control group.(5)Immunohistochemistry and western blot:compared to the control group,the experimental group showed high expression of CD31,increased expression of type I collagen and increased collagen I/III ratio.Conclusions:(1)ADSCs composited with SIS to repair abdominal wall hernia in rats can increase the strength of single SIS to repair abdominal wall defect.(2)ADSCs composited with SIS to repair abdominal wall hernia in rats can promote neovascularization.(3)ADSCs composited with SIS to repair abdominal wall hernia in rats can induce the synthesis of type I collagen in vivo.