Preparation And Performance Evaluation Of PP/PCL Anti-adhesive Composite Hernia Mesh

Hernia is one of the common diseases in general surgery.According to statistics,it has 3%~5% incidence in the world,more than 3.5 million new hernia patients every year in China.At present,hernia can only be treated by surgery.The use of hernia mesh significantly lower the recurrence rate and postoperative pain,but still not reach desired state.In this thesis,two types of large pore size,lightweight spindle-shape warp-knitted hernia mesh materials were designed and fabricated for reducing clinical complications,such as strong foreign body sensation,adhesion and pain.Then the physical,the mechanical and the biological performance were evaluated for the hernia mesh materials.In order to improve the long-term anti-adhesive after implantation and reduce the incidence of seroma,Polypropylene(PP)hernia mesh materials reinforced with Polycaprolactone(PCL)nanofibers as anti-adhesive composite hernia mesh which had longer degradation time and micro pore due to PCL nanofibers and large pore due to PP hernia mesh materials.The physical and the mechanical performance of PCL nanofibers membrane and anti-adhesive composite hernia mesh were analyzed.The results showed that two warp-knitted hernia mesh materials met the requirements of large pore size and lightweight,and withstand the maximum pressure of human abdominal wall.Two hernia mesh materials had similar anisotropic characteristics to human abdominal wall by uniaxial tensile test.Therefore,surgeons should pay more attention to place the hernia mesh in the right direction to avoid pain and recurrence caused by mismatch between hernia mesh and abdominal wall.According to bursting test results,it had different tensile strength on both side of hernia mesh materials,the tensile strength in technical back was larger than technical face.The difference of tensile strength on both sides was proportional to the difference of pore size.From the cytotoxicity and histopathological analysis,two hernia mesh materials had no toxicity to cells,similar organization growth and inflammation compared with two commercial hernia mesh.Through exploring the effect of PCL concentration and the ratio of mixture solvent on the morphology of electrospun nanofibers,the optimum solution concentration was 15%,and the ratio of DCM to DMF was 7:3.The optimal parameters were used to prepare anti-adhesive composite hernia mesh.Through the test results of morphology,pore diameter and contact angle of nanofibers membrane,the pore diameter and hydrophobic of disorder nanofibers membrane which were received by aluminum foil were higher than two pattern nanofibers membranes which were received by two warp-knitted hernia mesh materials.In theory,three types of membranes can prevent cell adhesion and growth.Mechanical property test results showed that pattern nanofiber membranes have anisotropic characteristics similar to hernia mesh materials.Cytotoxicity tests showed that anti-adhesive composite hernia mesh is non-toxic to cells.This thesis systematically studied the design,fabrication and performance evaluation of macroporous lightweight anti-adhesive hernia mesh materials,and explored the formation and property characterization of Polycaprolactone(PCL)nanofibers membrane and anti-adhesive composite hernia mesh.The results of this study have reference value for the further design and fabrication.