Study On The Degradation Of PGA、PLA Fibers And Its Bends In Vitro

The degradation rate and changes of the mechanical properties before and after degradation of the degradable biomedical materials have a significant impact on their medical applications. The requirements of the biomedical artificial scaffold may be stated as follows:excellent mechanical properties,good biocompatibility as well as an appropriate degradation rate to match the application time.Therefore,realizing the properties of biomedical materials can meet the needs of organizational reconstruction and restoration of function.In the field of degradable biomedical materials,PGA and PLA are two important synthetic polymer materials.They both have larger applications at home and abroad at present.PGA has a better biocompatibility.It is suitable for cell adhesion and proliferation,but the rate of degradation in the body is too fast,the new organization can not afford to the body load when PGA had lost their mechanical properties.PLA has a slower degradation rate to meet the mechanics request of the scaffold in the body,but due to the poor biocompatibility,it is not conducive to cell adhesion and proliferation.As a result,the way of physical blending or chemical copolymerization different proportions of PLA and PGA to get a better material,which has an appropriate degradation rate to match the speed of organizational reconstruction and also can meet the requirements of the strength and biocompatibility,has become the problems and hot spots of the research in the field of bio-degradable medical material.In this article,the basic properties of PLA,PGA fibers and their copolymer PGLA fibers by melt spinning were analyzed.Besides,different process parameters of spinning and drawing were selected to study the effects of winding speed and drawing temperature on the properties of PGA fibers and their performance during degradation.At the same time,the different intrinsic viscosities of PGA fibers were studied during the degradation.In addition,the author selected different PGA/PLA proportion to blending,through testing weight loss,thermodynamics properties,surface morphology and mechanical properties of the sample during degradation,to study the effects of blending proportion on performance during degradation.The study showed that PGA fibers in the intrinsic viscosity of 1.3dl/g winded at the speed of 100m/min,drawn at the temperature of 45℃,had better performance and a slower rate of degradation.After 12 weeks of in vitro degradation,it was found that PLA fiber had no significant change,and different proportion of PGA and PLA fiber had different degradation cycle.The result showed that the degradation rate of the blends accelerated with the increase of PGA.The rates of degradation could be controlled by changing the proportions of PLA and PGA fibers.It is a trend that making materials have appropriate biological structure,mechanical strength and cell affinity using new technologies on surface modification.In this paper,for the lower rate of degradation,poor hydrophilic and biocompatibility,it was studied by DBD and RF plasma treatment for PGA,PLA,PGLA and PGA/PLA blend fibers.The research showed that both DBD and RF had obvious effects,and the contact angle of all fibers had dropped.It was also reflected by infrared spectrum.The degradation experiment for the treated fibers showed that degradation cycles of the fibers after plasma treatment had shorted in some degree.The research on the degradation rate of PGA,PLA,PGLA and PGA/PLA blend fibers may give some references and experimental basis for the future of the PGA and PLA product development,preparation and applications.It may also lay a solid foundation for the further study of the PGA and PLA product development,speeding up its industrial production and promoting its clinical application.