Macrofungal Mediated Biosynthesis of Silver Nanoparticles and Evaluation of Its Antibacterial and Wound-Healing Efficacy.

Recently, the utilization of biological agents in the green synthesis of nanoparticles has been given interest. In this study, silver nanoparticles were synthesized from an aqueous extract of macrofungus (mushroom), namely Phellinus adamantinus, in a dark room using 20 µL of silver nitrate. Biosynthesized silver nanoparticles were confirmed by analyzing them using a UV-Vis (ultraviolet-visible) spectrophotometer. The synthesized silver nanoparticles were optimized at different pH and temperatures with various dosages of AgNO3 (silver nitrate) and fungal extracts. The synthesized AgNPs (silver nanoparticles) were characterized using TEM (transmission electron microscopy) and EDX (energy-dispersive X-ray) analyses, which confirmed the presence of silver nanoparticles. The size of the nanosilver particles was found to be 50 nm with higher stability. The mycosynthesized AgNPs showed effective antibacterial activity against strains of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (E. coli and Pseudomonas aeruginosa) bacteria. The minimum inhibitory concentration (MIC) was found to be 3.125 µg/mL by MIC assay. The MTT assay (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl-2H-tetrazolium bromide) was performed to study cytotoxicity, and reduced cell viability was recorded at 100 µg/mL. Silver-Polygalacturonic acid-Polyvinyl alcohol ((Ag-PGA)-PVA) nanofiber was prepared using the electrospinning method. The in vitro wound scratch assay was demonstrated to study the wound-healing efficacy of the prepared nanofiber. The wound-healing efficacy of the AgNP-incorporated nanofiber was found to be 20% after 24 h. This study will lay a platform to establish a unique route to the development of a novel nanobiomaterial and its application in antibacterial and wound-healing therapy.

In Vitro Antibacterial and Wound Healing Activities Evoked by Silver Nanoparticles Synthesized through Probiotic Bacteria.

The prospective application of probiotics is an adjuvant for the advancement of novel antimicrobial and wound-healing agents. Currently, probiotic bacteria are utilized for the biosynthesis of nanoparticles in the development of innovative therapeutics. The present study aimed at using nanoparticle-conjugated probiotic bacteria for enhanced antibacterial and wound-healing activity. In the present investigation, the probiotic bacteria were isolated from a dairy source (milk from domestic herbivores). They screened for antibacterial activity against infection-causing Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Bacillus subtilis and Staphylococcus aureus) pathogens. Further, the probiotic strain with higher bactericidal activity was used to synthesize silver, selenium, and copper nanoparticles. The isolated strain was found to be Lactiplantibacillus plantarum and it only has the ability to synthesize silver nanoparticles. This was verified using Ultra violet-Visible (UV-Vis) spectroscopy, where the test solution turned brown and the greatest UV-Vis absorptions peaked at 425 nm. Optimization studies on the synthesis of AgNPs (silver nanoparticles) are presented and the results show that stable synthesis was obtained by using a concentration of 1mM silver nitrate (AgNO3) at a temperature of 37 °C with pH 8. The FTIR (Fourier transform infrared spectroscopy) study confirmed the involvement of functional groups from the cell biomass that were involved in the reduction process. Additionally, biosynthesized AgNPs showed increased antioxidant and antibacterial activities. The nano silver had a size distribution of 14 nm and was recorded with HR-TEM (high-resolution transmission electron microscopy) examination. The EDX (energy dispersive X-ray) analysis revealed 57% of silver groups found in the nanoparticle production. The biosynthesized AgNPs show significant wound-healing capabilities with 96% of wound closure (fibroblast cells) being observed through an in vitro scratch-wound assay. The cytotoxic experiments demonstrated that the biosynthesized AgNPs are not extremely hazardous to the fibroblast cells. The present study provides a new platform for the green synthesis of AgNPs using probiotic bacteria, showing significant antibacterial and wound-healing potentials against infectious pathogens.

An in vitro study on the burn wound healing activity of cotton fabrics incorporated with phytosynthesized silver nanoparticles in male Wistar albino rats.

In modern therapeutics, chemically synthesized drugs have been reported as causing adverse effects including allergies, rashes, itches, and swelling. For the past few decades, silver nanoparticles (AgNPs) have widely been applied in medical domains due to their antimicrobial and wound healing properties. In the present study, different concentrations of phytosynthesized AgNPs-saturated cotton dress fabrics - in comparison to cotton fabrics treated with commercial ointment - were tested for 18days to assess their ability to speed the healing of rats' burn wounds. No significant difference in body weight was observed during the course of treatment as compared to the normal rat group. The cotton fabrics observed under Scanning Electron Microscopy (SEM) confirmed the distribution of AgNPs in the cotton fibers. Energy-Dispersive X-ray analysis (EDX) spectrum also authenticated the AgNPs' distribution. At the end of the experimental period, the wound healing efficacy of dressing containing commercial ointment (Burn Heal) was slightly lower than that of treatment containing 100µg/kg of body weight (kg b.w.) of AgNPs. Additionally, it was also observed that the wound contraction area was higher than that of the positive drug 100µg/kg b.w. treated group, which indicates comparatively better-quality activity of ointments with AgNPs with regards to their burn healing properties. The histological and SEM observations showed better fibril alignments in repaired skin when compared with the negative and positive control groups. Perhaps due to the tensile strength of the comparatively higher concentration of nanoparticles, Groups IV and V (which contained the most nanoparticles out of all the groups) showed much better healing properties than did the positive drug treated group VI. Altogether, increased-concentration AgNPs show increased recovery action in comparison to the positive drug treated group. This study provides additional insight into the incorporation of AgNPs in wound dressings for speedy recovery of burn wounds, for improved human welfare.