Flacourtia indica based biogenic nanoparticles: development, characterization, and bioactivity against wound associated pathogens

Hydrothermal assisted biogenic synthesis of silver nanoparticles: A potential study on virulent candida isolates from COVID-19 patients

Till now the exact mechanism and effect of biogenic silver nanoparticles on fungus is an indefinable question. To focus on this issue, the first time we prepared hydrothermal assisted thyme coated silver nanoparticles (T/AgNPs) and their toxic effect on Candida isolates were determined. The role of thyme (Thymus Vulgaris) in the reduction of silver ions and stabilization of T/AgNPs was estimated by Fourier transforms infrared spectroscopy, structure and size of present silver nanoparticles were detected via atomic force microscopy as well as high-resolution transmission electron microscopy. The biological activity of T/AgNPs was observed against Candida isolates from COVID-19 Patients. Testing of virulence of Candida species using Multiplex PCR. T/AgNPs proved highly effective against Candida albicans, Candida kruzei, Candida glabrata and MIC values ranging from 156.25 to 1,250 μg/mL and MFC values ranging from 312.5 to 5,000 μg/mL. The structural and morphological modifications due to T/AgNPs on Candida albicans were detected by TEM. It was highly observed that when Candida albicans cells were subjected to 50 and 100 μg/mL T/AgNPs, a remarkable change in the cell wall and cell membrane was observed.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

Biogenically Synthesized Polysaccharides-Capped Silver Nanoparticles: Immunomodulatory and Antibacterial Potentialities Against Resistant Pseudomonas aeruginosa

Bacterial infections are the key cause of death in patients suffering from burns and diabetic wounds while the use of traditional antibiotics has been growing steadily. Thus, in the present study, we are trying to introduce a paradigm shift strategy to improve chronic wound healing of bacterial infection. To that end, we have biologically synthesized silver nanoparticles (AgNPs) using Arthrospira sp polysaccharides, and evaluated their antibacterial efficacy with their safety pattern. Scanning electron micrographs showed spherical AgNPs coated with algal polysaccharides with an approximate size of 9.7 nm. Treatment of Pseudomonas aeruginosa with the AgNPs (0.5–1 μg/mL) resulted in a significant disruption in P. aeruginosa outer membrane, reduction in biofilm formation, and a significant decrease of production of alginate and pyocyanin along with a concentration-dependent reduction in β-lactamase activity. In addition, at the in vivo level, AgNPs displayed substantial activity to control P. aeruginosa infections in rat skin wounds with significant reduction in in COX-2 enzyme in both rat skin homogenate and serum samples. Furthermore, AgNPs facilitated wound curative in the P. aeruginosa infected model by reducing the hemorrhagic areas number and the infiltrated inflammatory cells. Taken all together, these biogenic nanoparticles showed unique properties in controlling bacterial wound infections and improving the healing process of damaged tissues via its direct and indirect effects.