Tag Archives: Valerio Pruneri

Mite silk as the basis for a new nanobiomaterial

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For the record, this is spider mite silk (I have many posts about spider silk and its possible applications on this blog; just search ‘spider silk’)..

The international collaborative team includes a Canadian university in combination with a Spanish university and a Serbian university. The composition of the team is one I haven’t seen here before. From a December 17, 2020 news item on phys.org (Note: A link has been removed),

An international team of researchers has developed a new nanomaterial from the silk produced by the Tetranychus lintearius mite. This nanomaterial has the ability to penetrate human cells without damaging them and, therefore, has “promising biomedical properties”.

The Nature Scientific Reports journal has published an article by an international scientific team led by Miodrag Grbiç, a researcher from the universities of La Rioja (Spain), Western Ontario (Canada) and Belgrade (Serbia), in its latest issue entitled “The silk of gorse spider mite Tetranychus lintearius represents a novel natural source of nanoparticles and biomaterials.”

In it, researchers from the Murcian Institute for Agricultural and Food Research and Development (IMIDA), the Barcelona Institute of Photonic Sciences, the University of Western Ontario (Canada), the University of Belgrade (Serbia) and the University of La Rioja describe the discovery and characterisation of this mite silk. They also demonstrate its great potential as a source of nanoparticles and biomaterials for medical and technological uses.

A December 17, 2020 Universidad de La Rioja press release (also on EurekAlert), which originated the news item, further explains the research,

The interest of this new material, which is more resistant than steel, ultra flexible, nano-sized, biodegradable, biocompatible and has an excellent ability to penetrate human cells without damaging them, lies in its natural character and its size (a thousand times smaller than human hair), which facilitates cell penetration.

These characteristics are ideal for use in pharmacology and biomedicine since it is biocompatible with organic tissues (stimulates cell proliferation without producing toxicity) and, in principle, biodegradable due to its protein structure (it does not produce residues).

Researcher Miodrag Grbi?, who heads the international group that has researched this mite silk, highlights “its enormous potential for biomedical applications, as thanks to its size it is able to easily penetrate both healthy and cancerous human cells”, which makes it ideal for transporting drugs in cancer therapies, as well as for the development of biosensors to detect pathogens and viruses.

THE ‘RIOJANO BUG’

Tetranychus lintearius is an endemic mite from the European Atlantic coast that feeds exclusively on gorse (Ulex europaeus). It is around 0.3 mm in size, making it smaller than the comma on a keyboard, while the strength of its silk is twice as high as standard spider silk.

It is a very rare species that has only been found so far in the municipality of Valgañón (La Rioja, Spain), in Sierra de la Demanda. It was located thanks to the collaboration of Rosario García, a botanist and former dean of the Faculty of Science and Technology at the University of La Rioja, which is why researchers call it “the Rioja bug” (“El Bicho Riojano”).

The resistance of the silk produced by Tetranychus lintearius is twice that of spider silk, a standard material used for this type of research, and stronger than steel. It also has advantages over the fibres secreted by the silkworm due to its higher Young’s modulus, its electrical charge and its smaller size. These characteristics, along with its lightness, make it a promising natural nanomaterial for technological uses.

This finding is the result of work carried out by the international group of researchers led by Miodrag Grbi?, who sequenced the genome of the red spider Tetranychus urticae in 2011, publishing the results in Nature: https://www.nature.com/articles/nature10640.

Unlike the red spider (Tetranychus urticae), the gorse mite (Tetranychus lintearius) produces a large amount of silk. It has been reared in the laboratories of the Department of Agriculture and Food of the University of La Rioja, under the care of Professor Ignacio Pérez Moreno, allowing research to continue. Red spider silk is difficult to handle and has a lower production rate.

Here’s a link to and a citation for the 2020 paper,

The silk of gorse spider mite Tetranychus lintearius represents a novel natural source of nanoparticles and biomaterials by Antonio Abel Lozano-Pérez, Ana Pagán, Vladimir Zhurov, Stephen D. Hudson, Jeffrey L. Hutter, Valerio Pruneri, Ignacio Pérez-Moreno, Vojislava Grbic’, José Luis Cenis, Miodrag Grbic’ & Salvador Aznar-Cervantes. Scientific Reports volume 10, Article number: 18471 (2020) DOI: https://doi.org/10.1038/s41598-020-74766-7 Published: 28 October 2020

This paper is open access.

Research into phase changes in solids and control

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A July 28, 2015 news item on ScienceDaily describes some practical reasons for research into phase changes from the Institute of Photonic Sciences (ICFO) in Spain in collaboration with Firtz-Haber-Institut der Max-Planck-Gesellschaft,

Rewritable CDs, DVDs and Blu-Ray discs owe their existence to phase-change materials, those materials that change their internal order when heated and whose structures can be switched back and forth between their crystalline and amorphous phases. Phase-change materials have even more exciting applications on the horizon, but our limited ability to precisely control their phase changes is a hurdle to the development of new technology.

A July 28, 2015 ICFO news release (also on EurekAlert), which originated the news item, describes the problem and the researchers’ solution,

One of the most popular and useful phase-change materials is GST, which consists of germanium, antimony, and tellurium. This material is particularly useful because it alternates between its crystalline and amorphous phases more quickly than any other material yet studied. These phase changes result from changes in the bonds between atoms, which also modify the electronic and optical properties of GST as well as its lattice structure. Specifically, resonant bonds, in which electrons participate in several neighboring bonds, influence the material’s electro-optical properties, while covalent bonds, in which electrons are shared between two atoms, influence its lattice structure. Most techniques that use GST simultaneously change both the electro-optical and structural properties. This is actually a considerable drawback since in the process of repeating structural transitions, such as heating and cooling the material, the lifetime of any device based on this material is drastically reduced.

In a study recently published in Nature Materials, researchers from the ICFO groups led by Prof. Simon Wall and ICREA Prof. at ICFO Valerio Pruneri, in collaboration with the Firtz-Haber-Institut der Max-Planck-Gesellschaft, have demonstrated how the material and electro-optical properties of GST change over fractions of a trillionth of a second as the phase of the material changes. Laser light was successfully used to alter the bonds controlling the electro-optical properties without meaningfully altering the bonds controlling the lattice. This new configuration allowed the rapid, reversible changes in the electro-optical properties that are important in device applications without reducing the lifetime of the device by changing its lattice structure. Moreover, the change in the electro-optical properties of GST measured in this study is more than ten times greater than that previously achieved by silicon materials used for the same purpose. This finding suggests that GST may be a good substitute for these commonly used silicon materials.

The results of this study may be expected to have far-reaching implications for the development of new technologies, including flexible displays, logic circuits, optical circuits, and universal memory for data storage. These results also indicate the potential of GST for other applications requiring materials with large changes in optical properties that can be achieved rapidly and with high precision.

Here’s a link to and a citation for the paper,

Time-domain separation of optical properties from structural transitions in resonantly bonded materials by Lutz Waldecker, Timothy A. Miller, Miquel Rudé, Roman Bertoni, Johann Osmond,  Valerio Pruneri, Robert E. Simpson, Ralph Ernstorfer, & Simon Wall. Nature Materials (2015)
doi:10.1038/nmat4359 Published online 27 July 2015

This paper is behind a paywall.