Mechanism and Antibacterial Activity of Gold Nanoparticles (AuNPs) Functionalized with Natural Compounds from Plants

Abstract

Recently, the biosynthesis of gold nanoparticles (AuNPs) has been widely studied and described. In the age of bacterial drug resistance, an intensive search for new agents with antibacterial properties or a new form of antibiotics with effective action is necessary. As a result, the antibacterial activity of AuNPs functionalized with natural compounds is being investigated more frequently. AuNPs biosynthesized with plant extract or functionalized with bioactive compounds isolated from plants could be particularly useful for pharmaceutical applications. The biosynthesized AuNPs are stabilized by an envelope, which may consist of flavonoids, phenolic acids, lipids and proteins as well as carbohydrates and vitamins. The composition of the natural coating affects the size, shape and stability of the AuNPs and is also responsible for interactions with the bacterial cell wall. Recently, several mechanisms of AuNP interactions with bacterial cells have been identified. Nevertheless, they are not yet well understood, due to the large diversity of plants and biosynthesized AuNPs. Understanding the antibacterial mechanisms allows for the creation of pharmaceutical formulations in the most useful form. Utilizing AuNPs functionalized with plant compounds as antibacterial agents is still a new concept. However, the unique physicochemical and biological properties of AuNPs emphasises their potential for a broad range of applications in the future.

Functionalization of niobium nitrogen-doped titanium dioxide (TiO2) nanoparticles with ethanolic extracts of Mentha arvensis

“…Additionally, some recent findings depict resonance in TiO 2 synthesis from ethanolic extracts of M. arvensis , where TiO 2 NPs emerged as spherical-shaped entities embodying dimensions within the size span of 60–80 nm [ 31 ]. Further, TiO 2 synthesized from the ethanolic leaves extract of M. arvensis is a captivating spherical and triangular garb, showcasing an average size of 60 nm.…”

“…Following this thermal treatment, a rapid cooling regimen ensued, succeeded by the incorporation of 2.5 mL of 10% trichloroacetic acid (C 2 HCl 3 O 2 ). The ensuing phase involved a centrifugal purification step, executed at 3,500 rpm for 12 min [ 31 ]. The ensuing pellet was systematically discarded, while the supernatant was harmoniously merged with an equal volume of double-distilled water and 0.1% (1 mL) ferric chloride (FeCl 3 ).…”

“…Consequently, this study is devoted to elucidating the functionalization of Niobium Nitrogen-Doped Titanium Dioxide (TiO 2 ) NPs by using M. arvensis ethanolic leaf extracts and delving into their antioxidant potential [ 30 ]. This endeavor aspires to contribute to our comprehension of the antioxidant attributes of Niobium Nitrogen-Doped Titanium Dioxide (TiO 2 ) NPs functionalized with M. arvensis ethanolic leaf extracts and their potential as a pioneering avenue for combatting oxidative stress [ 31 ].…”

Anti-inflammatory role of gold nanoparticles in the prevention and treatment of Alzheimer's disease

“…Therefore, AuNPs with LSPR peaks in the NIR region are more suitable for biomedical applications and have been intensively investigated for diagnostic imaging, drug-targeting delivery, and biosensors. 34 Secondly, the optical properties of AuNPs are also developed based on their SPR properties. Different wavelengths of AuNPs absorb different wavelengths of light, thus exhibiting different colors and photothermal effects.…”

Grewia asiatica leaves extract assisted green synthesis of gold nanoparticles and study of their antibacterial, antioxidant and photocatalytic potential

“…It becomes a strong competitor for silver. These NPs can effectively attack all types of bacteria and viruses compared to silver and other metals and are less hazardous and toxic to the environment when compared to other chemically synthesized nanoparticles (Timoszyk and Grochowalska 2022). Because of their resistance to surface oxidation, stability, exible surface characteristics, and low cytotoxicity, Au NPs are excellent for nanotechnologies such as drug delivery (Patel et al 2022).…”