The Preparation And Stufy Of Braided Structure Thread-embedding Materials For Acupuncture

Acupuncture treatment has a long history in China.With the development of modern science and technology,acupuncture treatment combined with modern biomedicine also had a great breakthrough and innovation.To some extent,using modern biomedical materials and on the basis of traditional meridian-collateral theory,acupoint catgut-embedding therapy could solve some problems of the traditional acupuncture treatment such as long treatment time,short duration and so on.Acupoint catgut-embedding therapy has made some great achievements in clinical medicine.Biodegradable polymer as one of the materials used in acupoint catgut-embedding therapy are embedded in the corresponding acupoint to make persistent stimulation and could achieve the same therapeutic effect of acupuncture.But with the absorption of thread-embedding materials,the stimulation would become milder and the effect of treatment reduces.To the issues,this paper attempts in the original thread-embedding materials to prepare new self-expanding embedding materials by using the method of chitosan coating.The new materials should produce selfexpanding effect and keep better rigidity to meet the sustained stimulation intensity after embedded.In this project,the biodegradable material PLA and PGA multifilament and PGLA braided yarns are studied as raw embedding materials.Five different kinds of braided yarns were made by blending different proportion of PGA/PLA multifilament in 12 knitting machine.The basic properties including morphology,mechanical properties and hydrophilicity were investigated.Then,the diameter and mass of materials in different degradation time were studied by in vitro degradation experiments.Results show that the braided yarns have different properties due to the different proportion of PGA/PLA multifilament.After coated by chitosan,the properties of hydrophilicity mechanical and self-expanding properties are improved obviously,and it illustrates that it is beneficial for the implants to has a continuous stimulating effect on the acupoints in the human body.Compared with these six braided yarns,PGLA braided yarn is more suitable for the embedding material because of its excellent mechanical hydrophilicity and degradation properties.Based on coating treatment can effectively improve the performance of the embedding materials,so this project also explored the method to improve coating efficiency.Low temperature plasma treatment process is simple,obvious effect,no pollution,and can adjust the plasma discharge parameters to optimize the modification effect and get the surface with different surface properties.In this project,the relationship between the plasma discharge parameters and the effect on the braided yarns is also discussed.Results show that the power and time of different treatments on PGLA braided yarns have different degree of influence,when the power is 200 W and processing time is 200 s,PGLA braided yarn has the most obvious effect,and the surface has obvious groove and convex marks,quality and strength loss.Because of the change of surface groups,the contact angle is reduced that means good hydrophilicity,can effectively improve the coating amount of the coating process,and effectively improve the coating effect.While the crosslinking degree and crystallinity of the braided yarn affect its hardness increase.Based on the surface treatment of PGLA braided yarn,to further explore and analyse the change of properties of PGLA braided yarn after the coating process.Also the degradation experiment was done to further study the relationship between the coating process and the performance of the PGLA braided yarn.Results show that when the coating chitosan concentration is 3%,and using short time-more times coating method,the overall coating effect is better.The obtained coating optimized parameters are repeated 4 times,each time is 10 min.In addition,the weight gain of PGLA braided yarn changes obviously during the coating process and the hydrophilicity and hardness improve better overall,it can satisfy the implanted materials’ continuous stimulation on acupoint effect.In the process of degradation,chitosan coating film protects the braided yarn,so it can effectively extend the degradation cycle.Based on the optimization of coating process,effects of different coating materials like chitosan and hyaluronic acid on PGLA braided yarn were also studied.Results show that the properties of PGLA braided yarn have great differences with different coating materials under the same coating process.With the increase of concentration,the viscosity is also increasing,so the coating amount of PGLA braided yarn is on the increase,and under the same concentration,the viscosity of the hyaluronic acid is far greater than the chitosan,so hyaluronic acid solution more easily attaches to the braided yarn surface.However,the greater the viscosity of coating material,the more interaction between molecules to form a network structure,resulting in the uniformity of coating effect.The mechanical properties of hyaluronic acid are less than chitosan,so the strength and hardness of PGLA braided yarn after hyaluronic acid coating are less than that after chitosan coating.The choice of coating materials depends on the degree of stimulation on the patient.Through these studies the properties of braided yarns thread-embedding materials with different coating materials and coating process can be improved in some extend,so some rules and useful conclusions can provide guidance and reference for the manufacture and further study of thread-embedding materials used in the acupuncture threapies.