Preparation And Performance Of CS/PCL Anti-adhesion Membrane After Laparoscopic Surgery

Laparoscopic surgery has the advantages of less injury,high safety and rapid postoperative recovery,but more than 50%of patients still have different degrees of postoperative adhesion.Blocking the contact between wound and other parts through physical barrier is the most direct and effective way at present.Compared with gel and solution anti-adhesion products,membrane products have the advantages of good physical barrier effect and long action time,so they are widely used in the field of anti-adhesion after laparoscopic surgery.In the carrier of membrane anti-adhesion materials,electrospinning membrane has high porosity and large specific surface area,which is conducive to the infiltration of nutrients and the inhibition of inflammation.It is an ideal anti-adhesion structure.Chitosan(CS)is a common anti-adhesion material with good biocompatibility,good anti-adhesion effect and excellent anti-inflammatory effect.However,its poor solubility,spinnability,hardness and fragility limit its wide application in membrane anti-adhesion materials.Polycaprolactone(PCL)has high biosafety,low price,good spinnability,soft mechanical properties and biodegradability.It is an ideal anti-adhesion auxiliary material.Based on the requirements of cost,environmental protection and biosafety in the process of product development and preparation,CS/PCL fiber membranes were prepared by plasma assisted surface coating and blending,and their physical and chemical properties and application environment of anti-adhesion membrane after simulated laparoscopy were tested and analyzed.The main research contents are as follows:(1)Preparation and morphology analysis of pure CS electrospun membranes.Using the mixed solution of acetic acid and water as solvent,pure CS electrospun membranes with mass volume fraction of 2%,3%and 4%were prepared by electrospinning technology.They were in the shape of"liquid beads"under SEM and had no fiber structure.Other schemes should be considered in follow-up research..(2)Preparation of CS coated PCL anti-adhesion membranes and their basic physical and chemical properties.The surface of PCL electrospun membranes were modified by O₂ plasma,and then CS with different concentrations were coated on the surface of PCL membranes by impregnation method.With the increase of CS solution concentration,the average diameter of fiber increases.FTIR test showed that CS and PCL in PCL membranes coated with CS were only physical blending.XRD test showed that the crystallinity of the material were improved after CS were coated on the surface.DSC and TGA tests showed that compared with PCL membrane,the thermal decomposition temperature of plasma assisted CS coated fiber membranes decreased and the melting temperature increased slightly.The contact angle test shows that the contact angle of PCL membranes coated with CS can be reduced to 0°within 1 minute,and have good hydrophilicity.The tensile test results showed that the breaking strength and elongation at break of PCL membranes coated with CS decreased compared with pure PCL membrane.The PCL membrane coated with CS(5%w/v)on the surface with breaking strength>2 MPa and elongation at break>20%is preferred for follow-up study.(3)Preparation of CS/PCL blended membranes and study on their basic physical and chemical properties.The blend electrospinning membranes with the mass ratio of PCL to CS ranging from 10:0 to 5:5 were prepared.After adding CS,the average fiber diameter decreased significantly,less than 1/5 of the diameter of pure PCL fiber.With the increase of CS content in the blended membrance,the average fiber diameter increases from 0.093?m increases to 0.199?m,the fiber unevenness also increases.FTIR test showed that CS and PCL were only physical blending.XRD test shows that with the increase of CS mass fraction,the crystallinity of the material first increases and then decreases.DSC and TGA tests showed that compared with pure PCL membrane,the thermal decomposition temperature of CS/PCL blended membranes decreased and the melting temperature increased slightly.After adding CS,the water contact angle of fiber membrane decreased from 130°to less than 50°.The tensile test results show that the fiber membranes are more rigid after adding CS,the breaking strength and modulus of the material increase,and the breaking elongation decreases significantly.(4)Performance of CS/PCL fiber membranes in simulated application environment.Compared with pure PCL fiber membrane,the bending deformation ability and bending elasticity of fiber membrane decreased after adding CS.The bending property of PCL membrane coated with CS is far inferior to that of blended f membranes.CS/PCL blended membranes have good humoral wettability,and there is no obvious change in fiber morphology after soaking,so there will be no material swelling.Fibroblast adhesion experiment showed that the cells on the fibrous membrane showed good morphology.Compared with pure PCL fiber membrane,the number of cell-adhesion of blended fiber membranes decreased significantly.Among them,the number of cells in CS/PCL blended fiber membranes with 30%and 40%CS mass fraction are only 60%of that in pure PCL membrane,so the anti-cell adhesion effect are the most significant.In conclusion,CS/PCL fiber membranes were prepared by plasma assisted surface coating and blending respectively.The basic physical and chemical properties of the fiber membranes and the properties under simulated laparoscopy were tested and analyzed.Based on the cost of raw materials,spinnability,mechanical properties and the effect of preventing cell adhesion,the CS/PCL blended membrane with 30%CS mass fraction is selected for the application research of anti-adhesion after laparoscopic surgery in the future.