Research On The Properties Of Surface Modification Of Filament And Nerve Conduit

In recent years,inducing nerve regeneration with artificial nerve conduits especially biodegradable tubes was considered to be a feasible method by many scholars both at home and abroad and it gradually became a hot research.Nerve conduits as implants,should not only have a certain mechanical strength to avoid wall collapse appeared in the process of nerve regeneration and hinder the growth of nerve,but also have good biocompatibility without causing a series of adverse reactions in the human body and were conducive to cell adhesion and proliferation at the same time.Therefore,it was important to study radial compressive property and biocompatibility of nerve conduits.Most of nerve conduits used biopolymer materials whose surface properties determined the biological reaction between material and human blood or tissue.Thus the surface modification is becoming an important means to improve the biocompatibility of materials.First,the radial compressive property of nerve conduits with hollow structure was studied.By testing the basic properties and radial compressive property,the paper mainly explore the perfect braiding parameters of nerve conduits with different specifications and the influence of inner diameter.Then,hydrogen peroxide treatment and ultrasonic treatment were used respectively to the surface modification of PGA,PLA and PGLA fibers.It was aim to find the optimum process parameters and the influence of various factors on basic performance,degradation property and biocompatibility by designing orthogonal experiment and analyzing the test data.At last,based on nerve regeneration process,we designed a new structure of nerve conduits on the basis of the original nerve conduits with hollow structure and deal with the tubes using hydrogen peroxide treatment.The purpose was to compare these two kinds of conduits and provide new ideas and methods for braided nerve conduits.Studies have shown that:Nerve conduits with PGLA(90:10)had better radial compressive property than PGLA(99:1).Inner diameter had a certain influence on nerve conduits,which had a great impact on the radial compression force and had less effect on the elastic recovery rate.After hydrogen peroxide treatment,the breaking strength of PGA,PLA and PGLA enhanced and contact angle reduced,improving the hydrophilic.The crystallinity of PGA decreased,while which of PLA and PGLA fiber increased.Biocompatibility of PGA,PLA and PGLA fibers were still good.In the orthogonal experiment,fiber type was the main factor,followed by hydrogen peroxide concentration and processing time.In the process of degradation,treated fibers had rougher surface,more salient point and worse uniformity.Considered separately for each fiber,the best results were PGA fiber with 8#,PLA fiber with 5#and PGLA fiber with 9#.After ultrasonic treatment,PGA,PLA and PGLA had larger breaking strength with smaller water contact angle and better hydrophilic.PGA and PGLA had lower crystalline and PLA had higher crystalline.The biocompatibility of PGA,PLA and PGLA fibers were still good.In the orthogonal experiment,fiber type was the main factor,followed by ultrasonic power,volume ratio of anhydrous ethanol and processing time.In the process of degradation,surface topography of treated fibers with surface cracks changed greatly.It is worth mentioning that PGLA fiber have serious phenomenon of curly.Considered separately for each fiber,the best results are PGA fiber with 5#,PLA fiber with4#and PGLA fiber with 2#.New nerve conduits with greater support structure provided a good channel for nerve regeneration and directed to guide the growth of axons.After hydrogen peroxide treatment,the radial compressive property of nerve conduits with new structure improved.