Fonksiyonel Pet Nano Fiberlerin Üretilmesi ve Yara Örtüsü Olarak Kullanmak Üzere Modifiye Edilmiş Pet Fiberlere Protein Kaplı Gümüş Nanoparçacıkların Adsorpsiyonu

Abstract

In this study, silver nanoparticles (S-AgNPs) coated with sericin were adsorbed on poly (ethylene terephthalate)-g-poly(hydroxyethylmethacrylate) (PET-g-HEMA) nanofibres and the use of the obtained material as wound dressing was investigated. Firstly, S-AgNPs at different concentrations were synthesized using silk sericin as a reducing agent, and the formation of S-AgNPs was proved with surface plasmon peaks observed at 420 nm using a UV-Vis spectrophotometer. The zeta potentials of S-AgNPs were investigated by Zeta-Sizer, their chemical structures were analyzed with fourier transform infrared spectroscopy (FTIR) and morphologies were examined with transmission electron microscope (TEM). Subsequently, PET fibers were grafted with HEMA using benzoyl peroxide as the initiator. Copolymers with different HEMA grafting yield (20, 55, 110, 175%) were characterized by scanning electron microscopy (SEM), FTIR and nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR) analysis and with the addition of HEMA to the structure, morphological and chemical iv changes in the fibers have been shown. In the electrospinning process, when the polymer concentration was 20% (in trifluoroacetic acid, w/v), the applied voltage was 12 kV, the flow rate of the polymer solution was 5 μL/min and the distance between the needle tip and the collector was 12 cm, continuous, smooth, bead-free nanofibers with diameter below 1000 nm were obtained from the original PET and PET-g-HEMA copolymers having 20 and 55% grafting yield. To be used as dressing, nanofiber membranes obtained from PET-g-HEMA copolymer with 55% grafting yield were selected and negatively S-AgNPs were adsorbed on the surface of the membranes. Modified membranes have been examined by SEM, UV-Vis, X-Ray fluorescence spectrometry (XRF), elemental, contact angle, mechanical, thermal, antibacterial and cytotoxicity analyzes. SEM, UV-Vis, contact angle, mechanical, thermal, antibacterial and cytotoxicity analyzes of the modified membranes have been examined. For antibacterial activity tests, disc diffusion test and liquid culture tests were performed using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) bacteria, it was found that the original nanofiber surfaces did not have antimicrobial effect, but the nanofibers modified with S-AgNPs had antimicrobial effect. For biocompatibility tests, methylthiazole diphenyl tetrazolium (MTT) test was performed using L929 fibroblast cell lines and it was observed that the viability rates of the cells incubated with the modified material extract did not decrease below 70% after 1 and 3 days incubation.

In in vivo studies, deep burn wounds created in Sprague-Dawley rats were closed with PET-g-HEMA nanofibers and macroscopic evaluations were made on determined days by calculating wound shrinkage. According to these evaluations, when compared with the control group (covered only with gauze), it was observed that the wounds that were covered with S-AgNPs closed faster. In addition, sections of tissue samples taken from wound areas were subjected to histological evaluation and thus, the effect of the nanofiber surface on epithelization was also examined.