The Research And Development Of Muga Silk Cosmetic Surgical Suture

At present,there are many types of cosmetic surgical sutures in the market,but none of them are ideal in aspects of line diameter,mechanical properties,knot fixation,stability,degradation and biocompatibility,and they still need to make compromises in use.For the same type of surgical suture,mulberry silk is one of the most important surgical sutures in China,which is widely used in skin suture,because it is superior to synthetic suture in knot fixation and softness.But the strength of silk monofilament is very low that cannot meet the demand of suture,and the strength is often enhanced by braiding,leading to increased diameter of the suture.This limits application of silk to the suture of the fine parts in cosmetic surgery.Therefore,it is of great clinical significance to develop surgical suture with small diameter and high strength.According to literatures,the research on muga silk mainly focuses on degumming and wearing,and the comprehensive performance evaluation is not comprehensive.As a kind of natural protein fiber,muga silk was not paid enough attention in the biomedical field,and few research was carried out.This research will evaluate the physical and biomedical properties of muga silk,and compare it with mulberry silk to explore the possibility of its application in cosmetic surgery suture.The results show that:(1)Muga silk was not easy to degum.The degumming rate of alkali and enzyme was 14.09% and 16.10% respectively.The degumming effect of enzyme was better than that of alkali.After degumming,the cross section of muga silk is flat rectangle,which is different from the irregular triangle or semi ellipse.As a suture,this flat surface shape is beneficial to increase the friction performance,and the test results show that the dynamic and static friction on the surface of muga silk is 9.66% and 12.70% higher than that of mulberry silk,respectively,which shows that muga silk is not easy to slip and more firmly after knot.(2)After degumming,the diameter and strength of muga filament are 16.14 um and 8.91cN/dtex,respectively,which are 1.6 and 2.5 times of that of mulberry filament.Muga silk monofilament can reach the strength standard of 11-0 specification suture without weaving,while the thinnest woven silk suture on the market is 6-0 specification.After knotting,the strength of the single filament of muga silk remaines 80%,which still meets the demand of stitching strength.After 15 s,the stress of muga silk decreases by 18.2% under the condition of 5% deformation,and then tends to be stable,which indicates that its supporting force to the wound is greater than mulberry silk,and it is not easy to cause secondary tear to the wound.(3)After degumming,the crystallinity of muga silk is 40.76%,which is 17.57% higher than that of mulberry silk,showing better stability.The thermogravimetry test also verifiies this result,which shows that muga silk can meet the process requirements of higher requirements better than mulberry silk.The aggregation structure of muga silk is similar to mulberry silk,including ?-fold structure and ?-helix structure.But there are also some differences,which leads to performance differences.There are a lot of hydrophilic groups in the amorphous area of muga silk,and its hygroscopicity is better than mulberry silk.It shows that muga silk can expand rapidly and fill the needle eye when it is infiltrated by body fluid during the operation,reduce the leakage of body fluid from the needle eye,and improve the suture quality.(4)In the 16 week degradation process,,the quality loss rate of muga silk is 16.22%,which is 11.77% higher than that of mulberry silk,indicating that muga silk degradation is faster;the strength reduction rate is 21.20%,which is 7.70% lower than mulberry silk,indicating that muga silk has a better effect of maintaining strength in the humoral simulation environment.Muga silk can not be completely degraded within 16 weeks,and still maintain more than 75% strength after degradation,which belongs to nonabsorbable suture material.(5)The cell proliferation rate of muga silk and mulberry silk is over 75%,which is relatively low toxic and safe.There was slight inflammatory reaction in the early stage of subcutaneous implantation of the two kinds of silk,but no inflammatory reaction after 84 days.It shows that muga silk and mulberry silk have grate biocompatibility.In conclusion,muga silk is superior to mulberry silk in terms of line diameter,mechanical properties,stability,hygroscopicity and degradability,similar to mulberry silk in terms of biocompatibility and good evaluation,so it is an ideal suture material for cosmetic surgery.