Stability-Enhanced Cisplatin Gold Nanoparticles As Therapeutic Anticancer Agents.

Using dendron chemistry, we developed stability enhanced, carboxylate surface modified (negatively charged dendron) AuNPs (Au-NCD). Since the carboxylate surface of Au-NCD is optimal for complexation with cisplatin (Pt) moieties, we further synthesized Pt loaded Au-NCD (Au-NCD/Pt) to serve as potential therapeutic anticancer agents. The size distribution, zeta potential and surface plasmon resonance of both Au-NCDs and Au-NCD/Pt were characterized via dynamic light scattering, scanning transmission electron microscopy and ultraviolet-visible spectrophotometry.

Polyethyleneimine/polyethylene glycol-conjugated gold nanoparticles as nanoscale positive/negative controls in nanotoxicology: testing in frog embryo teratogenesis assay- and mammalian tissue culture system.

Despite the great potential of using positively charged gold nanoparticles (AuNPs) in nanomedicine, no systematic studies have been reported on their synthesis optimization or colloidal stability under physiological conditions until a group at the National Institute of Standards and Technology recently succeeded in producing remarkably stable polyethyleneimine (PEI)-coated AuNPs (Au-PEI). This improved version of Au-PEI (Au-PEI25kB) has increased the demand for toxicity and teratogenicity information for applications in nanomedicine and nanotoxicology. In vitro assays for Au-PEI25kB in various cell lines showed substantial active cytotoxicity.

Photocatalytic activity of nanoparticles: the development of the standardized measurement for physiological conditions.

Recently a new International Standard for testing nanomaterial photocatalytic activity under physiological conditions was issued by Technical Committee 229 (Nanotechnologies) of the International Organization for Standardization (ISO 20814:2019 Nanotechnologies-Testing the photocatalytic activity of nanoparticles for NADH oxidation). The document offers a robust, high throughput photocatalytic assay using a bio-compatible indicator nicotinamide amide dinucleotide (NAD) and provides a screening tool to gauge nanomaterial potency for phototoxicity. This paper describes the measurement principles behind this assay, the scope of the standard and its validation through an interlaboratory comparison study using a traceable standard reference material (SRM 1898).

Quantitative Proteomic Analysis of Biogenesis-Based Classification for Extracellular Vesicles.

Extracellular vesicles (EVs) are traditionally divided into two major groups: (i) large vesicles originating from plasma membrane and called microvesicles, and (ii) small vesicles originating from the endoplasmic membrane and called exosomes. However, it is increasingly clear that the actual composition of a particular EV preparation cannot be adequately described with these two simple terms and is much more complex. Since the cell membrane origin of EVs predetermines their biological functions, the understanding of EV biogenesis is important for accurate interpretation of observed results.