l-Leucine for gold nanoparticles synthesis and their cytotoxic effects evaluation

Abstract

This work reports the preparation of water-soluble leucine capped gold nanoparticles by two single-step synthesis methods. The first procedure involves a citrate reduction approach where the citrate is used as reducing agent and leucine as capping/stabilizing agent. Different sizes of gold nanoparticles, citrate reduced and stabilized by leucine, Leu-AuNPs-C, with the mean diameters in the range of 21-56 nm, were obtained by varying the macroscopic parameters such as: concentration of the gold precursor solution, Au (III):citrate molar ratio and leucine pH. In the second procedure, leucine acts both as reducing and stabilizing agent, allowing us to obtain spherical gold nanoparticles, Leu-AuNPs, with a majority of 80 % (with the mean diameter of 63 nm). This proves that leucine is an appropriate reductant for the formation of water-soluble and stable gold nanoparticles colloids. The characterization of the leucine coated gold nanoparticles was carried out by TEM, UV-Vis and FT-IR analysis. The cytotoxic effect of Leu-AuNPs-C and Leu-AuNPs was also evaluated.

Amino Acid Functionalized Inorganic Nanoparticles as Cutting-Edge Therapeutic and Diagnostic Agents

“…Gold nanoparticles modified with leucine and lysine have less cytotoxicity in comparison to gold nanoparticles modified with glycine and aspartic acid (Figure e), at a concentration 50 μg/mL . This is contradictory to our preliminary knowledge.…”

“…The glutamate capped iron oxide is, therefore, beneficial over the pristine iron oxide nanoparticles in abating the tendency to produce reactive oxygen species. Gold nanoparticles modified with leucine 82 and lysine have less cytotoxicity in comparison to gold nanoparticles modified with glycine and aspartic acid (Figure 2e), at a concentration 50 μg/mL. 80 This is contradictory to our preliminary knowledge.…”

“…Lanthanides doped with ytterbium, gadolinium or erbium of the nonspherical particles can have a negative impact and may increase the toxicity of gold nanoparticles along with size. 82 The presence of sulfhydryl (−SH) group on cysteine (Table 2) may capture Ag + ions released, reducing the chance of cytotoxicity. Silica nanoparticles modified with arginine 90 are found to be cytotoxic at a concentration of 200 mg/mL.…”

“…The ideal size for initial maximum uptake by cells such as dendritic cells (DC) is 50 nm, which has been observed with gold, silver, and polystyrene nanoparticles. However, the difference in shape of the nonspherical particles can have a negative impact and may increase the toxicity of gold nanoparticles along with size …”

Gold Nanoparticles Synthesized with a Polyphenols-Rich Extract from Cornelian Cherry (Cornus mas) Fruits: Effects on Human Skin Cells

“…The colloids were stable for three weeks in solution (no aggregation was observed). Citrate-coated gold nanoparticles were obtained by the trisodium citrate reduction [17].…”