The Study On The Preparation And Properties Of GO/PET Artificial Ligament Scaffold

Background:With the rapid development and growth of our country's national strenth and improvement of living standards,the ligament injury incidence increased year by year.The most comman type of the ligament injury is anterior cruciate ligament injury of knee.Its incidence is nearly 1500/100000 in Switzerland,1200/100000 in New Zealand,and 3000/100000 in the United States.In our country,a conservative estimate of the annual ligament injury cases should be no less than 10 million of one year.Because of the unsatisfactory therapeutic effect,ligament reconstruction have become the most popular therapeutic method.The autologous or allogeneic tendon graft reconstruction was replaced by the artificial ligament graft reconstruction,because of it's inevitable complications and the scarcity of resource.The high cost of ligament reconstruction sugery can not be ignored.Nowadays,the most comman type of artificial ligament is LARS ligament,composed of polyethylene terephthalate.Nevertheless,the symmetry of PET's molecular structure and the high degree of crystallinity made it have a low surface energy,which makes it difficult for cells to adhere and encapsulate on PET fibers.The shortage of mechanical property led to the overcrowded fibers and a narrow Faserriss,which go against the ingrowth of surrounding tissues.Graphene oxide(GO)is the functional ramification of graphene,which is very similar in spatial structure.But GO has abundant active group,including hydroxyl,carboxyl,carbonyl,epoxy groups et.These active groups endowed with a good hydrophilicity and biological activity.However,no study is about recombination of GO and PET,and it remains unknow that whether GO can improve the mechanical properties and the bioactivation of PET.Objective:To explore the method of making GO/PET artificial ligament scaffold.Then we analyze the changes of the structure?the mechanical property?the hydrophilicity and bioactivation of GO-PET artificial ligament scaffold materials in vitro.Materials and Methods:1?Preparation of GO/PET tensile mechanical model and mechanical analysis:First,improved Hummers method to prepare GO powder.Then we use mixing fusion and injection molding process to prepare tensile mechanical models which contains 0%?2% and 3% GO.Mechanical tests are finishied by Testometric M350-20 KN universal testing machine,including datas about maximum load,breaking strength,tensile strength,elongation at break,modulus of elasticity.The data are statistical analysed.2?Preparation of GO/PET artificial ligament scaffold and property analysis:We use the melt-spinning technology to gain 2%GO/PET copolymerization fibers and PET fibers.Then we knit fibers into tows with a diameter of 1mm and a length of6 cm.Mechanical tests are finishied by Testometric M350-20 KN universal testing machine,including datas about maximum load,breaking strength,tensile strength,elongation at break,modulus of elasticity.The data are statistical analysed.water contact angles are tested using the contact angle measuring instrument.To investigate the bioactivation by co-culture with mesenchymal stem cells.And then we use the SEM to evaluate the degree of cell adhesion by observing the morphology,to evaluate the capacity of cell proliferation by using MTT method,to study the cell differentiation capacity by testing ALP activity.Results:1?The result proves that GO-PET tensile mechanical model have a significantly higher mechanical property than PET,especially for 2%GO/PET.2?GO/PET artificial ligament scaffold have a significantly higher mechanical property than PET.The results shows that the average of water contact angles have the remarkable difference in statistics between the two groups which GO/PET is 53.4±1.3809°.In comparison to PET scaffold,SEM shows a higher degree of cell adhesion.MTT method shows a lager capacity of cell proliferation,ALP activity test shows a higher cell differentiation capacity.Conclusion:Our study first comebine GO with PET and have successfully prepared GO/PET artificial ligament scaffold under the melt-spinning technology.Compare wih single PET artificial ligament scaffold,GO/PET shows a significant increase in mechanical properties.Meanwhile,the higher hydrophilicity and increacing cell adhesion ?proliferation and differentiation confirm that GO/PET artificial ligament scaffold has a better bioactivation.These properties could decrease ligament knitting density and promote cell growth which strongly agree the clinical demands.Our modification method has a great potential in clinical applications and a good scientific future.This method provides theoretical basis for ameliorating functional and biological reconstruction of LARS,the same goes for near and forward future curative effects.