Preparation, characterization and biological evaluation of silver nanoparticles and drug loaded composites for wound dressings formed from Lallemantia royleana seeds' mucilage

Abstract

After an injury, the wounds need to be covered with a dressing. Lack of absorptive potential and sticking of dressing with the wound causes pain and slows the healing process. The aim of this study was to develop wound dressings having more absorptive potential and less sticking with the wound. The hemicelluloses from Lallemantia royleana seeds possess desirable properties for a wound dressing. The hemicellulose was blended with chitosan/chitin and glutaraldehyde to enhance the absorptive properties of the hemicellulose through cross-linking. Two types of formulations incorporating silver nanoparticles and ciprofloxacin were prepared. The composites were characterized by elemental analysis, Fourier-transform infrared spectroscopy and scanning electron microscopy, and evaluated for their antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The dressings were subjected to in vivo studies on Albino rats. The dressings were found to be porous and the silver nanoparticles and drug particles were found to be uniformly distributed in the polymeric matrix. The composite containing ciprofloxacin released the drug in a sustained manner for 14-16 days. From extrapolation of the data, it was discovered that the formulation would release around 80% of ciprofloxacin in about two weeks. Silver-ciprofloxacin nano-composites exhibited comparable activity (zone of inhibition 19-30 mm) against E. coli to that of ciprofloxacin (standard, 21-35 mm) and relatively lower activity in case of S. aureus (zone of inhabitation 11-17 mm). The dressings did not stick to the wound site and the site remained wet during the healing process. Thus the use of hemicellulose from L. royleana seeds proved to be beneficial for preparing wound dressings with improved properties because of having high swelling index, porosity and spongy texture.

Keywords: Hemicelluloses; Lallemantia royleana; chitin; chitosan; drug delivery; wound healing.