Synthesis, Physicochemical Characterization, and Cytotoxicity Assessment of Rh Nanoparticles with Different Morphologies-as Potential XFCT Nanoprobes

Abstract

Morphologically controllable synthesis of Rh nanoparticles (NPs) was achieved by the use of additives during polyol synthesis. The effect of salts and surfactant additives including PVP, sodium acetate, sodium citrate, CTAB, CTAC, and potassium bromide on Rh NPs morphology was investigated. When PVP was used as the only additive, trigonal NPs were obtained. Additives containing Br− ions (CTAB and KBr) resulted in NPs with a cubic morphology, while those with carboxyl groups (sodium citrate and acetate) formed spheroid NPs. The use of Cl− ions (CTAC) resulted in a mixture of polygon morphologies. Cytotoxicity of these NPs was evaluated on macrophages and ovarian cancer cell lines. Membrane integrity and cellular activity are both influenced to a similar extent, for both the cell lines, with respect to the morphology of Rh NPs. The cells exposed to trigonal Rh NPs showed the highest viability, among the NP series. Particles with a mixed polygon morphology had the highest cytotoxic impact, followed by cubic and spherical NPs. The Rh NPs were further demonstrated as contrast agents for X-ray fluorescence computed tomography (XFCT) in a small-animal imaging setting. This work provides a detailed route for the synthesis, morphology control, and characterization of Rh NPs as viable contrast agents for XFCT bio-imaging.

Carbon Quantum Dots Conjugated Rhodium Nanoparticles as Hybrid Multimodal Contrast Agents

“…A series of Rh NPs were synthesized by using varying concentrations of Rh precursor ([Rh 3+ ]), while The synthesis of Rh NPs was accomplished via a green chemical route, where water was chosen as the solvent for the microwave (MW)-assisted hydrothermal synthesis. As a matter of fact, the synthesis of metallic, Rh-based NPs employing other synthesis meth-ods [12] has made the separation and purification steps nontrivial. The introduction of the sugar ligand, LODAN, provides abundant hydroxyl groups for the reduction reaction of the water-soluble Rh precursor, thus avoiding the use of organic solvents.…”

“…Recently, we have demonstrated the use of NP-based contrast agents for X-ray fluorescence computed tomography (XFCT) in preclinical research and for tumor detection using MoO 2 NPs, utilizing a liquid-metal-jet microfocus source [ 8 , 10 ]. Furthermore, we also validated the potential use of Rh- and Ru-based NPs as XFCT contrast agents, which have matching X-ray absorption profiles to the pencil beam X-ray source [ 11 , 12 , 13 ]. In order to improve the functionality and biocompatibility of the XFCT contrast agents, SiO 2 coating was introduced, where a fluorophore (Cy5.5) has been covalently attached to the SiO 2 matrix.…”

“…Rh nanostructures, including nanoshells, nanoframes and porous nanoplates, were recently reported through an inverse-directional galvanic replacement reaction [ 22 ]. Rh NPs synthesis was also reported through polyol reduction [ 11 , 12 ]. This approach, and other classical approaches, require multiple steps including synthesis, activation, isolation, and functionalization.…”

Design of Micro- and Nanoparticles: Self-Assembly and Application

“…Prof. Toprak’s scientific group suggested another example of the controlled synthesis of the nanoparticles [ 10 ]. The effect of the addition of a series of salts and surfactant additives (poly(vinyl pyrrolidone), sodium acetate, sodium citrate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and potassium bromide) on the morphology of Rh nanoparticles was investigated.…”

Optical and X-ray Fluorescent Nanoparticles for Dual Mode Bioimaging

“… 5 , 6 Furthermore, the potential use of Rh and Ru based NPs as XFCT contrast agents has also been demonstrated. 7 , 8 With an established library of potential contrast agents for XFCT, an increase in the functionality of the NPs is a natural step.…”