Cadmium selenide (CdSe) quantum dots have gained increased attention for their potential use in biomedical applications. This has raised interest in assessing their toxicity. In this study, water-soluble, cysteine-capped CdSe nanocrystals with an average size of 15 nm were prepared through a one-pot solution-based method. The CdSe nanoparticles were synthesized in batches in which the concentration of the capping agent was varied with the aim of stabilizing the quantum dot core. The effects of the CdSe quantum dots on DNA stability, aggregation of blood platelets, and reducing activity of iron were evaluated in vitro . DNA damage was observed at a concentration of 200 μg/mL of CdSe quantum dots. Furthermore, the CdSe nanocrystals exhibited high reducing power and chelating activity, suggesting that they may impair the function of haemoglobin by interacting with iron. In addition, the CdSe quantum dots promoted aggregation of blood platelets in a dose dependent manner.

A novel, solution-based route to biocompatible, cysteine-capped gold–zinc telluride (Au–ZnTe) core–shell nanoparticles with potential in biomedical applications is described.

Purpose: To investigate the development of mammary tumours in female Sprague-dawley rats through a simple subcutaneous injection of human adenocarcinoma breast cells (MCF7) in combination with basement membrane matrix (BME

This study reports a solution based, low temperature route towards the synthesis of water soluble cysteine capped zinc telluride (ZnTe) nanoparticles under the influence of variations in pH and reaction time. The optical properties of the ZnTe nanoparticles display broad emission peaks ranging between 365-415 nm, which make them useful for imaging and biological labelling applications. Transmission electron microscopy (TEM) and high resolution TEM studies indicated that the particles are uniform in size and shape, however at the 2 hour reaction time interval the nanoparticle growth enters a transition phase where the morphology changes from nanospheres to nanorods. The formation of the ZnTe nanoparticles relative to reaction temperature, pH and time is typical of the oriented attachment growth mechanism. X-ray diffraction patterns confirmed the crystalline cubic phase. The surface charge of the functionalised ZnTe was also determined. The fluorescence properties and optical stability of the ZnTe nanoparticles in DNA plasmid pGEMT Easy were studied using fluorescence (365-395 nm filter) and phase-contrast (UV 2A 330-380 nm filter) microscopy techniques.

Novel gold-zinc telluride (Au-ZnTe) core-shell nanoparticles were synthesized to support surface modifications for enhanced drug delivery in cancer therapeutics. Knowledge of the biosafety and biocompatibility properties of these materials within biological systems is very limited and needs to be evaluated before their potential bio-applications may be demonstrated. We report the and bio-interactions of the Au-ZnTe nanoparticles, which were exposed to various human cancer and healthy cells, an immune simulation using peripheral blood mononuclear cells, followed by the analysis of cytokine expression. Acute exposure studies using low (50 μg ml), intermediate (500 μg ml) and high (1500 μg ml) concentrations of the Au-ZnTe particles were used to investigate histopathological effects in rats. Normal human mammary epithelial and colon cells in addition to human breast, prostate and colon cancer cells displayed cell viability between 86.4 ± 7.4% and 99.0 ± 3.6% when co-cultured with core-shell nanoparticles for 48 hours. Acute exposure studies using rat models displayed no significant changes in full blood counts, liver and kidney enzyme regulation and histopathology. These findings confirmed that Au-ZnTe core-shell nanoparticles display biosafety and biocompatibility features which can be exploited in future bio-applications.