Fabrication and characterization of biopolymers with antibacterial nanoparticles and Calendula officinalis flower extract as an active ingredient for modern hydrogel wound dressings

Abstract

Hydrogels are three-dimensional networks that can absorb moisture up to several times their weight and have many medical and biological applications. In this paper, the fabrication and characterization of a three-component chitosan (CS) / sodium alginate (SA) / polyvinyl alcohol (PVA) hydrogel with various weight percentages (0, 5, 10, 15, and 20) wt% of Ag2O/SiO2 with Calendula officinalis flower extract as an active ingredient are fabricated as a novel and green wound dressing. After forming bio-nano composites utilizing the cross-linking technique, Fourier transform infrared (FT-IR) spectroscopy is applied to determine and prove the functional groups added to the CS/PVA/SA at the whole step. X-ray diffraction (XRD) analysis is performed to prove the crystalline and amorphous structure of Ag2O/SiO2 NPs. The field emission scanning electron microscope (FE-SEM) analyses and Energy-dispersive X-ray spectroscopy (EDS) are performed to confirm the morphology of the composition and check the elements to increase wound healing. Atomic force microscope (AFM) examination is done to prove and determine surface roughness and pores. The tensile test is performed to determine the tensile strength and mechanical properties of nanocomposites. Also, by immersing nanocomposites in the simulated body fluid (SBF) and phosphate buffer salt (PBS), the swelling ratio is determined, and the release of Calendula officinalis flower extract is measured in PBS. Finally, the synthesized hydrogel's water vapor transmission rate (WVRT) and then antibacterial tests are determined. This research proves that with the increase of Ag2O/SiO2 NPs to 20% wt., the biofilm's tensile strength and mechanical properties and all healing properties have improved significantly. Producing these films is very effective in improving skin infections. Finally, the thermogravimetric analysis (TGA) is applied to estimate the thermal stability of the biopolymer films with various percentages of mesoporous Ag2O/SiO2 nanoparticles.