Inhibition of Bacteria Associated with Wound Infection by Biocompatible Green Synthesized Gold Nanoparticles from South African Plant Extracts

Abstract

Unlike conventional physical and chemical methods, the biogenic synthesis of gold nanoparticles (GNPs) is considered a green and non-toxic approach to produce biocompatible GNPs that can be utilized in various biomedical applications. This can be achieved by using plant-derived phytochemicals to reduce gold salt into GNPs. Several green synthesized GNPs have been shown to have antibacterial effects, which can be applied in wound dressings to prevent wound infections. Therefore, the aim of this study is to synthesize biogenic GNPs from the South African Galenia africana and Hypoxis hemerocallidea plants extracts and evaluate their antibacterial activity, using the Alamar blue assay, against bacterial strains that are known to cause wound infections. Additionally, we investigated the toxicity of the biogenic GNPs to non-cancerous human fibroblast cells (KMST-6) using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. In this paper, spherical GNPs, with particle sizes ranging from 9 to 27 nm, were synthesized and fully characterized. The GNPs from H. hemerocallidea exhibited antibacterial activity against all the tested bacterial strains, whereas GNPs produced from G. africana only exhibited antibacterial activity against Pseudomonas aeruginosa. The GNPs did not show any significant toxicity towards KMST-6 cells, which may suggest that these nanoparticles can be safely applied in wound dressings.

Synthesis of Biogenic Gold Nanoparticles from Terminalia mantaly Extracts and the Evaluation of Their In Vitro Cytotoxic Effects in Cancer Cells

“…The selectivity of M TMR-AuNPs (25 °C) and M TMSB-AuNPs (70 °C) on the three cancer (MCF, HepG2 and Caco-2) cells was within the selectivity index range from 6.5 to 82.2. The results corroborate with the finding of [ 53 ] that showed that biogenic AuNPs synthesized from the South African Galenia africana and Hypoxis hemerocallidea plants extracts showed that there was no significant reduction in viability of KMST-6 cell after 24 h treatment with AuNPs with concentrations up to 32 nM [ 16 ]. The same finding has been demonstrated by Patra [ 67 ], showing that AuNPs were non-toxic towards Hek293T cells.…”

“…Moreover, the presence of elements such as calcium and potassium can be due to the micronutrients in the TM extracts used in the synthesis. The weak signals for oxygen in the spectra may have originated from the biomolecules bound to the surface of the NPs [ 52 ], Cu from the support HRTEM grid and film and Co from the lenses of the microscope [ 16 ].…”

“…Moreover, utilizing plant extracts as reducing agents for the synthesis of AuNPs is advantageous owing to the availability of the plants and simplicity of the approach. Plant-mediated synthesis of AuNPs will not only allow large-scale production but will also reduce cost and time involved in the synthesis [ 16 ].…”

Green Synthesis of Gold Nanoparticles Capped with Procyanidins from Leucosidea sericea as Potential Antidiabetic and Antioxidant Agents

“…The extent of ZP is therefore, a subject of repulsion and attraction that has been used to estimate how long the nanoparticle dispersions would remain stable. The negative zeta-potential values obtained for the Au NPs fall in the range that is typical of stable colloidal dispersions [72]. The ZP measurement for the nanomaterials was repeated on the seventh day through to the fourteenth day showing only slight changes.…”

“…The method description of [72] was adopted. Slight changes were only in the monitoring period, which was 0, 12 and 24 h. The stability was evaluated as soon as the solutions were mixed with the nanoparticles and after incubation at 37 • C.…”