Silver Nanoparticles and Glycyrrhiza glabra (Licorice) Root Extract as Modifying Agents of Hydrogels Designed as Innovative Dressings

Abstract

The interest in the application of plant extracts as modifiers of polymers intended for biomedical purposes is constantly increasing. The therapeutical properties of the licorice root, including its anti-inflammatory and antibacterial activity, make this plant particularly promising. The same applies to silver nanoparticles showing antibacterial properties. Thus the main purpose of the research was to design hydrogel dressings containing both licorice root extract and nanosilver so as to obtain a system promoting wound regeneration processes by preventing infection and inflammation within the wound. The first step included the preparation of the plant extract via the solid-liquid extraction using the Soxhlet extractor and the synthesis of silver nanoparticles by the chemical reduction of silver ions using a sodium borohydride as a reducing agent. Subsequently, hydrogels were synthesized via photopolymerization and subjected to studies aiming at characterizing their sorption properties, surface morphology via scanning electron microscopy, and their impact on simulated physiological liquids supported by defining these liquids’ influence on hydrogels’ structures by FT-IR spectroscopy. Next, the tensile strength of hydrogels and their percentage elongation were determined. Performed studies also allowed for determining the hydrogels’ wettability and free surface energies. Finally, the cytotoxicity of hydrogels towards L929 murine fibroblasts via the MTT reduction assay was also verified. It was demonstrated that developed materials showed stability in simulated physiological liquids. Moreover, hydrogels were characterized by high elasticity (percentage elongation within the range of 24–29%), and their surfaces were hydrophilic (wetting angles below 90°). Hydrogels containing both licorice extract and nanosilver showed smooth and homogeneous surfaces. Importantly, cytotoxic properties towards L929 murine fibroblasts were excluded; thus, developed materials seem to have great potential for application as innovative dressings.

Biosynthesis of Silver Nanoparticles Using Roots of Glycyrrhiza glabra and Evaluation of Their Effect Against some Virulence Factors of Opportunistic Systemic Mycoses Fungi

“…Glycyrrhiza glabra AgNPs roots at sub-MIC were tested for their impact on fungal isolate viability using the MTT (3-[4, 5-dimethylthiazol-2-y1]-2, 5-diphenyl tetrazolium bromide) assay, The yellow tetrazolium MTT in the MTT assay is changed into an insoluble form using the oxidoreductase enzyme (Formazan) Dimethyl sulfoxide (DMSO) dissolves the formazan, producing a purple solution whose absorbance at 590 nm is correlated with the quantity of cells, Every experiment was carried out in duplicate, containing 1 milliliter of each fungal isolate at a concentration of 0.5 x 10 8 cells/ml in test tubes and 1 milliliter of sub-MIC AgNPs in treatment tubes. The tubes were then incubated for 24 hours at 35±2 o C, 96-well flat-bottom microplates were pre-incubated for two to three hours at 37 degrees Celsius with 5% CO 2 , after that, 50 µl of each treatment and control were added to each well, and then 50 µl of MTT reagent was added to each well, after the solution was drained, each well received 150 µl of MTT solvent, which caused a purple solution to develop, An Eliza reader was used to measure the purple solution's absorbance at 590 nm [16].…”

Antioxidant, Anti-Inflammatory Effects and Ability to Stimulate Wound Healing of a Common-Plantain Extract in Alginate Gel Formulations

“…A great sorption ability was observed that indicated the possibility of absorbing a wound exudate. Surface hydrophilicity and elasticity (approximately, 30% flexibility) indicated the possible use of these developed hydrogels as dressing materials to support regenerative processes in tissue injury [20,21].…”