The Preparation Of 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 PGLA are studied as raw embedding materials.The basic properties including morphology,mechanical,thermal properties and hydrophilicity were investigated.Then,the diameter and mass of materials in different degradation time were studied by in vitro degradation experiments.Results shows that PLA monofilament and PGLA braided yarn have excellent mechanical properties.Compared with the other properties of PLA,PGLA has better hydrophilicity and degradation speed.In order to evaluate the rigidity of thread-embedding materials,a characterization method was proposed.The method was to test the compressive strength of arched samples by using compression tester and it was also verified and optimized.The results shows the method is feasible.The thread-embedding materials were coated by chitosan to make self-expanding materials.Based on the studying of the variation tendency of mass,diameter,mechanical properties,rigidity,hydrophilicity of PLA and PGLA thread-embedding material with coating,single coating parameters were optimized.The self-expanding effect and rigidity of PLA and PGLA with coating were studied by in vitro degradation experiments.Finally,PGLA thread-embedding material were coated through orthogonal experiment and the optimal coating parameters were obtained.The results shows that the hydrophilicity and rigidity of PLA and PGLA thread-embedding materials with coating increase.As for the PLA-0 and PLA-1,the optimal single factor for coating time,concentration and times is 70 min,3%,6-times and 60 min,3% or 3.5%,7-times respectively.Though PLA thread-embedding material with coating could not produce the self-expanding during the degradation,the diameter is always bigger than the raw monofilament and the rigidity can keep stable.For PGLA thread-embedding material,the optimal single factor for coating time,concentration and times is 40 min,3.5%,7-times,and the materials with coating could produce obvious self-expanding.Finally,60 min coating time,3.5% coating concentration and 7-times coating times are chosen by the orthogonal process of coating PGLA.Through these studies,the properties of thread-embedding materials with chitosan coating could 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 material used in the acupuncture threapies.