28 December 2012

Quantum dots from worms

Earthworms turned into a factory for the production of quantum dots

Andrey Vasilkov, ComputerraYou have to be a real scientist to guess how to use earthworms not for fishing or even for obtaining vermicompost, but as living plants synthesizing nanoparticles with certain properties.

Recent studies have shown that the digestive system of earthworms can be used to obtain a biocompatible form of quantum dots.

Earthworm Lumbricus rubellus (photo: Dr. Jake G. Bundy)

Markers for luminescent diagnostics are widely used in modern medicine. In studies at the subcellular level, they should have the size of nanoparticles. Cadmium telluride (CdTe) is considered a promising material, but tellurium and cadmium themselves are quite toxic.

In order to reduce toxicity and improve distribution in tissues, it is necessary to develop an effective method for obtaining water-soluble forms. To do this, a group of researchers from King's College in London used earthworms of the species Lumbricus rubellus. They were placed for eleven days in soil enriched with salts of cadmium chloride and sodium tellurite.

In the process of feeding worms, cadmium telluride nanoparticles were formed. They selectively accumulated in the tissue surrounding the intestines of worms and performing the function of detoxification.

Chlorogenic tissue is a place of accumulation of cadmium telluride nanoparticles

The resulting quantum dots were isolated and then successfully used to visualize the structures of living cells. Under UV irradiation, they glowed green.

Example of images of laser scanning confocal microscopy
with luminescent cadmium telluride quantum dots
(photo: King's College London)

Additionally, it was found that the coating of cadmium telluride nanoparticles with polyethylene glycol makes it possible to observe their capture by macrophages.

The results of the work (Sturzenbaum et al., Biosynthesis of luminescent quantum dots in an earthworm) are published in the journal Nature Nanotechnology – VM.

Portal "Eternal youth" http://vechnayamolodost.ru28.12.2012

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