Polymer Electrospun Membrane For Preventing Postoperative Abdominal Adhesio

Abdominal adhesions are a common postoperative complication that can cause pain in patients and increase the risk of re-operation.Besides surgical removal,anti-adhesion film serving as a medical barrier is used to prevent tissue adhesion after surgery,which can separate the injured area from adjacent tissues and organs.Among various biomaterialsbased anti-adhesion films,fiber membranes constructed by electrospinning technology have received widespread attention in the field of anti-adhesion treatment due to their lightweight,flexible texture,and good mechanical properties,making them ideal antiadhesion materials.However,the anti-adhesion effect of electrospun fiber membranes is still limited.Therefore,enhancing the anti-adhesion ability of medical membranes remains a great challenge.Polyester is commonly used to construct electrospun polymer films to prevent abdominal adhesions due to excellent fiber formation and mechanical properties.However,from the perspective of different stages of in situ tissue regeneration,the efficacy of anti-adhesion and pro-regeneration is limited due to the lack of biological activity at the material-tissue interface and the induction of excessive inflammatory response.This project aims to use electrospinning technology to prepare fiber membranes and modify their surfaces to improve the outcome of anti-adhesion.Further,to render the membrane with anti-inflammation feature,anti-inflammatory ingredients were loaded into the anti-adhesion membrane.The inhibitory effect on abdominal adhesions by fibrious membranes was studied and related mechanism of action was explored.First,poly(lactideco-caprolactone)(PLCL)electrospun fiber membrane was prepared and coated by GelMA solution containing photo-initiator.After being irradiated by ultraviolet light(UV),the surface hydrogel coating was formed to produce a composite membrane with favorable hydrophilicity and biological activity.Inflammation is closely related to the formation of adhesive tissue.Further,chondroitin sulfate(CS)was loaded into poly(lactic-co-glycolic acid)(PLGA)electrospun membranes.It was anticaipated that the addition of antiinflammatory materials would eliminate the excessive inflammation at the wound to prevent adhesion.In vitro experiments including the characterization of physical performance and cell compatibility of electrospun membranes were studied.Second,abdominal adhesion models in SD rats were constructed to test the efficacy of electrospinning membranes.Macroscopic observation,pathological section observation,immunofluorescence staining,and ELISA detection were used to analyze the activation of fibrinolytic system and regulation of the immune environment.Then,the mechanism of abdominal adhesion prevention was examined.It was found PLCL/GelMA film has good mechanical properties with the Young’s modulu of 0.81± 0.05 MPa,the maximum load of 6.58±1.02 N and failure strain of 810.6±90.63%.In vitro cell compatibility indicated that the membrane showed no cytotoxicity to fibroblasts.PLCL/GelMA membrane significantly up-regulated the expression of tissue type plasminogen activator(t-PA),down-regulated the production of plasmin activator inhibitor-1(PAI-1),activated the fibrinolytic system,and promoted the secretion of MMP9.Thus,the deposition of collagen in ECM was decreased,inhibiting the formation of adhesive tissue.More importantly,PLGA/CS membrane increased the proportion of M2 macrophages in inflammatory cells,promoted the secretion of anti-inflammatory factors,and reduced the secretion of pro-inflammatory factors,while the injured abdominal wall was completely repaired after 21 days.By regulating the inflammatory environment in damaged tissues,excessive inflammatory reactions were reduced,thereby reducing the production of adhesive tissues.Overall,surface gelatinization or intruding bioactive polymers to electrospun film is a promising approach for developing bioactive barrier for preventing postoperative abdominal adhesions.Bioactive fibrous membrane provides a new treatment strategy for abdominal adhesions,which broad application prospects in regenerative medicine.