Electrospun Polyvinyl Alcohol Loaded with Phytotherapeutic Agents for Wound Healing Applications

Abstract

In this paper, hydroalcoholic solutions of Thymus vulgaris, Salvia officinalis folium, and Hyperici herba were used in combination with poly (vinyl alcohol) with the aim of developing novel poly (vinyl alcohol)-based nanofiber mats loaded with phytotherapeutic agents via the electrospinning technique. The chemical structure and morphology of the polymeric nanofibers were investigated using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The addition of Thymus vulgaris, Salvia officinalis folium, and Hyperici herba extracts to the pure polyvinyl alcohol fibers led to changes in the morphology of the fibers and a reduction in the fibers’ diameter, from 0.1798 µm in the case of pure polyvinyl alcohol to 0.1672, 0.1425, and 0.1369 µm in the case of polyvinyl alcohol loaded with Thymus vulgaris, Salvia officinalis folium, and Hyperici herba, respectively. The adapted Folin–Ciocalteu (FC) method, which was used to determine the total phenolic contents, revealed that the samples of PVA–Hyperici herba and PVA–Thymus vulgaris had the highest phenol contents, at 13.25 μgGAE/mL and 12.66 μgGAE/mL, respectively. Dynamic water vapor measurements were used in order to investigate the moisture sorption and desorption behavior of the developed electrospun materials. The antimicrobial behavior of these products was also evaluated. Disk diffusion assay studies with Escherichia coli, Staphylococcus aureus, and Methicillin-resistant Staphylococcus aureus were conducted on the developed nanofibers in order to quantify their phytotherapeutic potential.

Phosphorylated Curdlan Gel/Polyvinyl Alcohol Electrospun Nanofibres Loaded with Clove Oil with Antibacterial Activity

“…PCurd and PVA do not present the antimicrobial activity (Figure S3 and Table S1 from Supplementary Data), so this effect is due to the loaded CEO. As in other studies [36,66], the different sensitivity of Gram-positive and Gram-negative bacterial strains to the action of natural antimicrobial agents can be observed. This behaviour can be attributed to the structure of the bacterial cell wall, which contains a more diffusible mucopeptide layer in the case of Gram-positive bacteria, while the in the case of Gram-negative bacteria, the diffusion rate of lipophilic antibacterial compounds was reduced by a lipopolysaccharide layer [52,67].…”

“…A gentamicin disk (10 µg) was used as a positive control. All Petri dishes were incubated at 37 °C for 24 h. The antimicrobial activity was assessed by measuring the diameter of the inhibition zones formed by each sample tested [ 36 ].…”

Tunable Properties via Composition Modulations of Poly(vinyl alcohol)/Xanthan Gum/Oxalic Acid Hydrogels

“…The antibacterial activity of the PVA/XG hydrogels was evaluated against Gram positive bacteria ( Staphylococcus aureus 25,923 ATCC ) and Gram negative bacteria ( Escherichia coli 25,922 ATCC ) according to a method adapted from a previously reported work [ 25 ].…”

Electrospun Copoly(ether imide) Nanofibers Doped with Silver-Loaded Zeolite as Materials for Biomedical Applications

“…The bacterial strains Staphylococcus aureus ATCC 25923 (Gram-positive) and Escherichia coli ATCC 25922 (Gram-negative) were selected as indicators for determining the antimicrobial potential of co-PEI electrospun membranes and are reference and representative pathogenic microorganisms to which the microbial group belongs …”

“…For this, the samples were cut in the form of 5 mm discs and were put in contact with two reference bacterial strains: Staphylococcus aureus ATCC 25923 (Gram-positive bacteria) (Thermo Fisher Scientific INC, Dartford, UK) and Escherichia coli ATCC 25922 (Gram-negative bacteria) (Thermo Fisher Scientific INC, Dartford, UK). The protocol was presented in a previous paper . The diffusimetric method is based on the placement of test samples on the surface of a culture medium validated for such tests (Mueller Hinton Agar, Biorad) seeded with a microbial suspension with a cell density equivalent to a 0.5 McFarland turbidity standard (1.5 × 10 8 cfu/mL).…”