No abstract

In-depth kinetic insight into the catalytic reduction of nitrophenol pollutant using gold–carbon nanoparticles is described.

Gold nanoparticles coated with proteins have shown extraordinary biocompatibility which advanced to several nanomedicine engineering applications. We synthesized protein-coated gold nanoparticles using green and chemical reduction routes for cellular uptake study. In the current work, we coated gold-aryl nanoparticles of the type AuNPs-C 6 H 4-4-COOH with BSA, collagen, zein and lysozyme proteins. Both routes were carried out without phase-transfer catalysts or extraneous stabilizing agents. High crystallinity of the AuNPs synthesized by the green route can be seen in the transmission electron microscopy images. Osteosarcoma cancer cells are malignant bone tumors with abnormal cellular functions. Studies using MG-63 cells will provide mechanistic suggestions on the details of the amplification in tumors. We studied the cellular uptake of the bioconjugates by MG-63 osteosarcoma cells using laser confocal fluorescence microscopy (LCFM) and flow cytometry. In the LCFM study, BSA-AuNPs was uptaken most efficiently of all protein-coated gold nanoparticles synthesized by the green route. Zein and lysozyme coated nanoparticles, though small sizes, prepared by the green method were not efficiently uptaken by MG-63. The two nanoparticles are negatively charged and zein is also a hydrophobic coat. The difference in hydrophobicity and charge might have affected the internalization. All of those coated nanoparticles that were efficiently uptaken can potentially be used as diagnostic and therapeutic agents for osteosarcoma.

Binding DNA on nanoparticles was pursued to form nanoplatform for formation of non‐viral gene system. Carboxyl derivatized gold‐aryl nanoparticles can bind with biodegradable cationic polyelectrolytes such as polydiallyldimethylammonium chloride (PDADMAC). In our study, we used gold‐aryl nanoparticles (AuNPs) treated with PDADMAC to form conjugates with non‐thiol or non‐disulfide modified oligonucleotide DNA. Both AuNPs‐DNA and PDADMAC‐AuNPs‐DNA biomaterials were characterized using UV–Vis, dynamic light scattering (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and agarose gel electrophoresis. UV–Vis showed a red shift in the plasmon peak as compared with unconjugated AuNPs. DLS measurements also showed difference in the size of AuNPs‐DNA and PDADMAC‐AuNPs‐DNA. AFM and TEM results showed proper conjugation of DNA with AuNPs. Gel electrophoresis proved the presence of interaction between PDADMAC‐AuNPs and negatively charged DNA. The binding of DNA in the described bioconjugate enhanced its protection against nuclease degradation and prolonged its presence in the digestive environment of DNase‐I. From the results we expect that these biomaterials can be used in nanomedicine with emphasis on non‐viral gene system.

We synthesized protein-coated gold nanoparticles using green and chemical reduction routes for cellular uptake study. In the current work, we coated gold-aryl nanoparticles of the type AuNPs-C₆H₄-4-COOH with BSA, collagen, zein and lysozyme proteins. Both routes were carried out without phase-transfer catalysts or extraneous stabilizing agents. High crystallinity of the AuNPs synthesized by the green route can be seen in the transmission electron microscopy images. <a>Osteosarcoma cancer cells are malignant bone tumors with abnormal cellular functions. Studies using MG-63 cells will provide mechanistic suggestions on the details of the amplification in tumors. </a>We studied the cellular uptake of the bioconjugates by MG-63 osteosarcoma cells using laser confocal fluorescence microscopy (LCFM) and flow cytometry. In the LCFM study, BSA-AuNPs was uptaken most efficiently of all protein-coated gold nanoparticles synthesized by the green route. Zein and lysozyme coated nanoparticles, though small sizes, prepared by the green method were not efficiently uptaken by MG-63. The two nanoparticles are negatively charged and zein is also a hydrophobic coat. The difference in hydrophobicity and charge might have affected the internalization. All of those coated nanoparticles that were efficiently uptaken can potentially be used as diagnostic and therapeutic agents for osteosarcoma.