Production and characterization of hybrid nanofiber wound dressing containing Centella asiatica coated silver nanoparticles by mutual electrospinning method

Abstract

The aim of this work is to produce a therapeutic and antimicrobial nanofiber wound dressing material with suitable air permeability, water vapor transmission, water absorption, porosity, thermal and mechanical strength. For this purpose, first of all, Centella asiatica (CA) coated silver nanoparticles (CA-AgNPs) are synthesized with using CA extract as reducing and stabilizing agent. The green synthesized CA-AgNPs are characterized by UV–Vis spectroscopy, transmission electron microscope (TEM), zeta potential and fourier transform infrared (FTIR) spectroscopy measurements. The obtained CA-AgNPs give a single peak in the 420–430 nm range between 200 and 700 nm due to surface plasmon resonance (SPR). The average zeta potential and size of CA-AgNPs is found to be −30.4 mV and 14.8 ± 7.3 nm, respectively. Then, poly caprolactone (PCL) and polyethylene oxide (PEO) nanofibers composition containing CA-AgNPs is synthesized by mutual electrospinning method. Before electrospinning, the PCL solution (12% w/v in chloroform/methanol (70%/30%, v/v)), PEO solution (3.5%, w/v in water) and PEO solutions containing 1%, 5% and 10% (v:v) of CA-AgNPs are prepared. In electrospinning experiments, to synthesis the PCL/PEO nanofibers containing CA-AgNPs, an electrospinning set-up consisting of two high voltage sources, an aluminum rotary roller collector and two syringe pumps (one with a double syringe and the other with a single syringe) is used. To produce the wound dressing materials, PEO solutions containing CA-AgNPs are placed on the double syringe pump and PCL solution is placed on the single syringe pump. The surface and physico-chemical properties of the produced hybrid nanofibers are characterized by field emission scanning electron microscopy (FESEM), energy dispersion spectrometry (EDS), FTIR, X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area and porosity analyzer. Also, the thermal and mechanical properties of the obtained materials are investigated. In addition, the air permeability, water uptake capacity, water contact angle, water vapor transmission, in vitro degradation and silver release behavior of the samples are investigated. The results show that mutual dual-spinneret electrospinning technique combines the features of dissimilar components without corruption. Moreover, the in vitro degradation profile and silver release results show that these nanofibers could be used in wound dressing applications in the long term. With antimicrobial studies, PEO/PCL nanofibers containing 5% and 10% CA-AgNPs are found to be effective against Staphylococcus aureus, Escherichia coli and Candida albicans. Also, the cytotoxic properties of nanofibers are investigated by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and results show the good biocompatibility for L929 fibroblast cells. Results reveal that CA-AgNPs loaded PCL/PEO hybrid nanofibers materials synthesized in this study has a promising potential for wound healing applications.