Synthesis of Au Nanoparticles in Natural Matrices by Liquid-Phase Plasma: Effects on Cytotoxic Activity against Normal and Cancer Cell Lines

Abstract

Wrapping of gold nanoparticles (AuNPs) with a biocompatible matrix, to gain AuNP colloids, is a general strategy to synthesize the AuNPs for biomedical purposes. This work reports the synthesis of AuNP colloids in the aqueous solution of several natural matrices using a liquid-phase plasma process. Two classes of natural substances used are sugars (including: glucose, fructose, and sucrose) and biopolymers (including: carboxymethyl cellulose, sodium alginate, and gelatin). All are negatively charged water-soluble substances that are claimed to be sources of energy for cells to grow and have a high potential to be compatible with them. The study has emerged since one question arises: “Do these matrices also promote the growth of cancer cells?” The synthesis is performed by generating plasma across a pair of electrodes immersed in an aqueous solution of a natural matrix containing a gold precursor (HAuCl4·3H2O). Two concentrations of the matrices (0.5 and 1.0% w/v) are used, and the plasma treatment times are varied (0, 10, and 30 min). The effect of the type and concentration of natural matrices as well as the plasma treatment time on the formation of AuNPs, along with their physical and chemical properties, including morphology, size, hydrodynamic diameter (d h), colloidal stability, and charge on the AuNP surface, is evaluated. We find that the charge of the AuNP surfaces could be altered by the plasma treatment. Eventually, cytotoxicity test results against normal (MRC-5) and cancer (H460 and HeLa) cell lines could not only answer our opening question but also suggest a rather complex response. Our findings indicate the great potential of the obtained AuNP colloids as a part of cancer therapy.

Solution Plasma Processing Single‐Atom Au1 on CeO2 Nanosheet for Low Temperature Photo‐Enhanced Mars–van Krevelen CO Oxidation

“…Second, in the MvK mechanism, the lattice oxygen participates in the CO oxidation and is essential to make the oxygen exchange loop closed. To address this issue, we labeled a portion of the lattice oxygen in the sample with the isotope 18 O, [39] named Au 1 /Ce 18 O 2 -H, to further verify the reaction mechanism (Figure 5b). After the addition of 13 CO, the presence of 18 O 13 C 16 O (M/Z = 47) in the product was detected by mass spectrum.…”

“…To address this issue, we labeled a portion of the lattice oxygen in the sample with the isotope 18 O, [39] named Au 1 /Ce 18 O 2 -H, to further verify the reaction mechanism (Figure 5b). After the addition of 13 CO, the presence of 18 O 13 C 16 O (M/Z = 47) in the product was detected by mass spectrum. No 18 O 13 C 16 O appeared in the product of the sample Au 1 /Ce 16 O 2 -H without 18 O labeling.…”

“…After the addition of 13 CO, the presence of 18 O 13 C 16 O (M/Z = 47) in the product was detected by mass spectrum. No 18 O 13 C 16 O appeared in the product of the sample Au 1 /Ce 16 O 2 -H without 18 O labeling. This proves that lattice oxygen in the CeO 2 -support indeed reacts with CO molecules during CO oxidation, which is consistent with the MvK mechanism.…”

Cuboid Cu(HBTC)(H2O)3 synthesis via plasma pretreatment of trimesic acid solution

“…Plasma with liquid has been applied in the synthesis of various materials like carbon materials [21,22] and metal nanoparticles [23,24] and also in the functionalization of nanomaterial surface. [25][26][27] Research on the synthesis of MOFs by plasma with liquid has been conducted recently [28,29] ; however, the effects of plasma, especially on organic ligands, have not yet been fully explained.…”

Synthesis of a metal–organic framework by plasma in liquid to increase reduced metal ions and enhance water stability

“…Plasma is a unique reaction eld and has the advantage of being able to reduce and functionalize species using electrons and radicals. These characteristics have been widely utilized even in liquid phase for the synthesis of various materials such as carbon materials 22,23 and metal nanoparticles 24,25 and for introducing functional groups in materials. 26 Using plasma, it may be possible to synthesize functional MOFs with reduced metal ions or additional functional groups.…”