• Fabrication of Polyvinyl alcohol/Silk Fibroin Bilayered Nanofibers Containing ZnO Nanoparticles for Wound Dressing Yeganeh Rahimi, Mitra Naeimi*
  • yeganeh rahimi,1 dr mitra naeimi,2,*
    1. Biomedical Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
    2. Biomedical Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran


  • Introduction: The major problem of wounds is bacterial infection which is an important cause of delay in wound healing process. Treatment of burns and skin wounds is a major medical challenge. In order to care burn, wound dressings could be used. The characteristics of an ideal wound dressing material were summarized as follows: (a) protects the wound from physical damage and microorganisms, (b) is compliant and durable, (c) is non-toxic, non-adherent, and non-irritant, (d) allows gaseous exchange (e) adsorbs excessive humidity of the wound. Using nanomaterials such as ZnO nanoparticles in combination with wound dressing is a method to overcome the problem and also accelerates the healing process. In this research we have developed bilayered fibrous structures prepared from synthetic and natural polymers. Polyvinyl alcohol (PVA) nanofibers were used as substrate and silk fibroin (SF) nanofibers containing ZnO nanoparticles (NPs) were used as second layer.
  • Methods: PVA solution (10% wt) was prepared in distilled water and stirred at 300 rpm for 3 hours at 70 ͦC. Electrospinning was performed at different parameters at room temperature and fibers were collected on an aluminium foil. SF was extracted from bombyx mori silk cocoons. Freeze-dried SF was dissolved in formic acid in order to prepare 10% wt solution. In the next stage of electrospinning, the SF solution containing 0.1 % ZnO NPs was used. The prepared bilayered fibrous structures were characterized by scanning electron microscopy (SEM), mechanical properties, wettability, and antibacterial analysis.
  • Results: The SEM images showed uniform fibers with mean diameters ranging from 251±5 nm to 334±7 nm. The fibers were obtained by optimization of electrospinning parameters, such as voltage and distance. According to antibacterial analysis, the ZnO NPs containing structures exhibited antibacterial activity against staphylococcus aureus. The prepared bilayered electrospun structures could be a good candidate for wound dressing applications. Mechanical properties showed that bilayered structure have increased tensile modulus and strength in contrast to PVA monolayer. Water contact angle was decreased and reached to 40 degree. The increase in wettability indicates that the nanofibrous structures have the ability to absorbed excessive water molecules and secretions of the wound.
  • Conclusion: ZnO NPs incorporated PVA/SF fibrous structures was prepared. The present results showed that application of ZnO NPs in bilayered scaffolds is effective in the bacterial reduction. The results showed that bacterial load reduction of PVA/SF nanofibers containing ZnO NPs, was significantly different with control sample (p<0.05). Mechanical properties and wettability of the fibers are also improved in bilayered structures.
  • Keywords: Electrospining, bilayered structures, wound dressing, PVA