میثم معزی

Antibacterial suture yarns containing antibiotic drugs can play an important role in preventing the infection and holding tissues together to achieve wound closure. In this research, the possibility of production drug loaded nano yarns from a mixture of chitosan/polyvinyl alcohol (PVA/CS) (70:30) and poly(lactic acid) (PLA) was assessed by combining dual‐electrospinning technique with aligned fibers collection. For this, CS/PVA solution was injected from one syringe and PLA from another one. The effect of weight ratio of PLA-PVA/CS (100:0, 80:20 and 60:40), collector speed (500, 800, 1100 rpm) and voltage (10, 15 and 20 kV) on the diameter and morphology of fabricated nanofibers was assessed. Fabricated nanofibers with the length of 70 cm were twisted for manufacturing suture yarns. The results showed that fabrication of structure with the finest diameter was possible with the weight ratio of PLA-PVA/CS (60:40), the applied voltage of 15 kV, spinning distance of 17 cm and the rotational speed of about 1100 rpm. The diameter of produced nanofibers in this condition was about 290±42 nm. Then, tetracycline hydrochloride (T) loaded PLA-PVA/CS nanofibers (PLA/T-PVA/CS) were produced with optimum condition and the drug (5 wt. %) was loaded in PLA solution. FTIR analysis of drug loaded yarn exhibited the most important functional groups of chitosan, PVA, tetracycline hydrochloride and PLA in PLA-PVA/CS structure. Contact angle data for PLA-PVA/CS and PLA/T-PVA/CS was about 89±3 ° and 30±2 °, respectively. The result of the antibacterial test indicated that the PLA/T-PVA/CS nanofibrous yarns were the most suitable sample with the prominent antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia coli with inhibition zones of 17.5 and 20 mm, respectively. It seems that the fabricated nanofiber based yarns with suitable morphological characteristics, hydrophilicity nature, and prevention of the surgical infectio