Study On The Degradation Of PGA,PLA Fibers And Textile Structure Scaffold For Tendon 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.Only with these 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 copolymering 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 both the polylactic acid (PLA) and polyglycolic acid(PGA) fibers by melt spinning were measured.In order to discuss the effect of different states of aggregation upon the degradation process,four kinds of braided sutures with different components(PGA/PLA=6/0,4/2,2/4,0/6), bundle and braided of PGA fibers in different states of aggregation were studied by testing the weight loss,thermal properties,surface morphology and mechanical properties.At the same time,the author selected the raw materials of different viscosities for spinning with different process parameters to study the intrinsic viscosity,drawing temperature and draft multiple on the properties of PGA fibers and their performance during degradation.The study showed that different states of aggregation would influence the properties of degradation to a certain extent.Bundles of PGA fibers degraded faster than the braided suture.The rates of degradation could be controlled by changing the proportions of PLA and PGA fibers.PGA fiber drawn at the temperature of 30℃had better performance and a slower rate of degradation than others under the same spinning conditions.Drawn by 8 times,the PGA fibers made from the polymer with the intrinsic viscosity of 1.4dl/g had the slowest rate of degradation.The braided sutures with different components(PGA/PLA= 6/0,4/2,2/4,0/6) were adopted to prepare four kinds of circular single jersery knitted fabrics as the outer sheath of the scaffold respectively using the small-diameter circular knitting machine, and then manufactured a new type scaffold for tendon tissue engineering using sheath-core structure.The author generally analyzed the changes in the performance of the single jersery knitted fabrics and the scaffold(4PGA/2PLA) with sheath-core structure for tendon tissue engineering during degradation in vitro.The research on the degradation performance of PGA,PLA fibers and textile structure tendon scaffold may give some references and experimental basis for the future of the PGA and PLA product development,tissue engineering scaffolds preparation and applications.It may also lay a solid foundation for the further study of the textile structure scaffold for tendon tissue engineering,speed up the tissue-engineered tendon,ligament product of industrial production and promote its clinical application.