Toxicity of azo-dyes combined with TiO2 nanoparticles

Azo-dyes are organices compounds frequesntly used for food colring for example in sweets. A characteristic feature of az-=dyes is the axo-group (-N=N) as part of the chromophore. In parallel, nanoparticles (NPs) are more and more used as food additives and this, the encoubter of NPs with azo-dyes is highly likely. In particular, TiO2 NPs are inciroporated into foods under the tearm E171

Nano-bio Interactions

Due to there extremely small size, nanoparticles display a unique set of characteristics, which differ significantly form bigger moieties. These characteristics also shape their interaction with biological entities. There large surface-to-volume area, for instance, makes particles in the nano- and micro-range very reactive. Clubmoss spores are an example of naturally occurring microparticles

Nanotechnology and azo-dyes in sweets

Nanotechnology is a fast growing field and consider as a key-technology of the 21st century. Nanoparticles are not only used in high-tech products or medical devices but are also more and more incorporated in food producers, for example in sweets. In addition, for food-coloring, azo-dyes are frequently used which makes an encounter of azo-dyes and nanoparticles unavoidable, The aim of this work was the isolation and characterisation of these dyes without including nanoparticles in a selected sweet product

Nanoparticle tracking analysis

Due to their extremely small size, nanoparticles cannot be analyses by conventional approaches such as light microscopy. To visualise particles in the nanoscale range, a combination of an ultra-microscope and a laser illumination unit has to be applied. This combinatory technique is called Nanoparticle Tracking Anlysis (NTA) and can be used of thr nalysis of particles in a size range of approximately 10 nm up to 1 μm in liquid suspension

Nano-chip for cancer diagnostics

Exosomes are vesicles with a size range of 30 to 50nm, which are secreted by a cell into its surroundings..

Active drug targeting

Over 100 years ago, Paul Ehrlich first proposed the side-chain theory to explain how living cells mount an immune response in reaction to an infection. His theory stated that upon the encounter of a threat, cells express side-chains to bind dangerous toxins. These side-chains, which he later named receptors, can break off the cell and circulate throughout the body (i.e. antibodies). Specific antibodies link to particular antigens in the same way that Emil Fischer proposed enzymes bind to their receptors, “as lock and key”. Ehrlich described these so-called “keys” or antibodies as “magic bullets”, which target toxins without harming the body. In recent years, research has focused on using antibodies not only for detection of infection, but also as aids for drug targeting. Thereby, antibodies are bound to the surface of carriers (e.g. nanoparticles) and facilitate a directed transport to a specific organ or site in the body. Aptamer- peptide- or folic acid-doped carriers furthermore have been shown to specifically target cancer cells. By using hydrophilic structures as carriers (e.g. polyethylene glycol), negative side effects resulting from the accumulation of innate proteins can be prevented. Currently, there are drug carriers in the pre-clinical development phase for the treatment of bowel cancer. Thereby, nano polymer capsules coated with a specific antibody are used to target a glycoprotein expressed on bowel cancer cells. The polymers have a size of approximately 500 nm and are produced with a so-called “layer-by-layer” procedure. Once the carrier has reached its target site, the drug needs to be released in a controlled manner. This can be facilitated, for example, by applying a magnetic field in the case of iron oxide particles. Once these particles are taken up by the cells, magnetic radiation can be used to excite the particles, resulting in the rupture of the cell and subsequent cell death

Medical applications based on nanotechnology

Poly-lactic-co-glycolic acid can form nanoparticles which can be applied in nanomedicine as delivery vehicle for therapeutic agents. Here the aim is to reduce negative side-effects and to obtain higher local concentrations at the site of action. This work is about determining the binding-capacity of PLGA nanoparticles to several substances, applying a small set of model proteins. Our aim was to find out, whether PLGA nanoparticles can transport drugs in order to make drug targeting in medicine easier. This would show us a new section of medicine with new ways of therapy methods

Gold and Silver - but safe?

Gold (Au) and silver (Ag) nanopartucles (NPs) are frequently used in medicine (drug delivery, wound dressings) but also more and more icorporated in every-day life products, such as functional clothing. Therfore, a comprehensive dafety assessment of such particles is essential. Teh aim of this work was the investigation of the suitability of standard DIN-EN-ISO protocolis for cytotoxicity assessment of NPs