Development and characterization of silk and poly L Lactic acid based sutures

Abstract

Silk braided sutures with three different structures are produced using a circular braiding machine The effect of gauge length extension rate and braid angle on tenacity and knot strength of silk braided sutures are studied In all the three structures silk sutures tested at longer gauge length and lesser test speed showed higher values of tenacity and knot strength Also out of all three structures silk sutures fabricated at lower braid angle showed higher values of tenacity and knot strength than the other structures The effect of newlinenormal load sliding speed and braid angle on the frictional properties of silk braided sutures are studied In all the three structures it is observed that there is decrease in the coefficient of friction with the increase in normal load and sliding speed Also silk sutures fabricated at lower braid angle showed lower value of friction than other structures The antimicrobial activity of the silk sutures is determined using the Agar Diffusion Method and no zone of inhibition is found against both E coli and S aureus bacteria This indicates that silk sutures do have poor resistance to bacteria Hence to impart bacterial resistance characteristics silk sutures are treated with two types of antimicrobial agents namely tetracycline hydrochloride and chitosan newline