Silver and gold nanoparticles from tannic acid: synthesis, characterization and evaluation of antileishmanial and cytotoxic activities

Abstract

Gold (Au0) and silver (Ag0) nanoparticles were synthesized using tannic acid (TA) as both reducing and stabilizer. Nanoparticles formation, stability, and interaction with TA were compared to citrate-coated nanoparticles and monitored by UV-Vis, zeta potential, and transmission electron microscopy. TA coating resulted in a red-shift and broadening of bands compared to citrate-coated nanoparticles (NPs-Cit). AgNPs-TA and AuNPs-TA are negatively charged with mean surface charge of -29.4 mV and -29.6 mV, respectively. TEM images showed polydispersety of AuNPs-TA (6-42 nm) and aggregation of AgNPs-TA (12-71 nm). In vitro assays of Leishmania amazonensis promastigotes showed an increment of antileishmanial activity for AgNPs-TA in relation to AgNPs-Cit, while AuNPs-TA and AuNPs-Cit did not affect the protozoas at tested concentrations. CC50 value for AgNPs-TA suggested that TA attenuates nanosilver toxicity comparatively to its precursor (Ag+). This investigation can contribute to the development of new, green, and fast produced drugs aiming at leishmaniasis treatment.

Biogenic synthesis of silver nanoparticles using Brazilian propolis

“…In the same figure, evaluating AgNP‐P as a function of time, in 24 hr (Figure a), it was possible to perceive the increase of the intensity of its absorbance, indicating a greater formation of the nanoparticles, as well as a displacement of the band of SPR for longer wavelengths, of 412 nm with 30 min, to 420 nm in 24 hr, similar to that obtained in literature with a shift from 414 nm (2 hr) to 422 nm (24 hr) . In general, these deviations refer to an increase in particle size whereas the increase in the peak width indicates a tendency to the polydispersity of the samples …”

“…33 In general, these deviations refer to an increase in particle size [38][39][40] whereas the increase in the peak width indicates a tendency to the polydispersity of the samples. 41 Such information was complemented by DLS, through analysis of the hydrodynamic diameter of the nanoparticles and the index of AgNP-P throughout 30 minutes, considered a value consistent with a monodispersed system. 42 Similar to the values found by other studies that evaluated Indian propolis with 113.6 nm and PDI 0.165.…”

Green synthesis of silver nanoparticles: biomolecule-nanoparticle organizations targeting antimicrobial activity

“…238 Lopes et al reported that green synthesized AgNPs using tannic acid (TA) officered antileishmanial activity. 239 El-khadragy et al reported clinical efficacy of biosynthesize AgNPs against Leishmania in in vivo rat model study. Biosynthesized spherical silver nanoparticle (116 nm) using Moringa oleifera extract resulted in a signicant reduction in the average size of leishmaniasis cutaneous lesions compared with untreated mice.…”

Facile Fabrication of Oxygen-Releasing Tannylated Calcium Peroxide Nanoparticles

“…Tannic acid (TA), a polyphenolic biomolecule, is a versatile surface modifier due to the presence of phenolic hydroxyl groups, aromatic rings, and galloyl groups [ 13 , 14 ]. In addition, the tendency of TA to coordinate with metal ions has been exploited to synthesize Ag and Au nanoparticles [ 15 , 16 ]. Most importantly, additional coordinate bridges are formed between the catechol moieties of TA and calcium ions of Ca-alginate nanoparticles [ 17 ].…”