Tag Archives: Swedish University of Agricultural Sciences

Damaging coronavirus with mineral nanoparticles paves way to new disinfection technology

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A January 30, 2025 news item on phys.org announces research from Sweden and Estonia that could lead to a new way of disinfecting surfaces against the coronavirus and other similar viruses,

A new way to neutralize coronavirus and other membrane-surrounded viruses has been discovered by researchers from the Swedish University of Agricultural Sciences [SLU] and the University of Tartu [Estonai]. Certain mineral nanoparticles were found to damage the membrane of the virus, making it less able to enter human cells. The mode of action that is demonstrated has not been discussed in previous research. The technology works at room temperature and also in the dark, offering a range of benefits for disinfecting surfaces, air and water.

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A January 30, 2025 Swedish University of Agricultural Sciences press release, which originated the news item, provides a little more detail about the research,

”Using this new knowledge, it should be easy to create surfaces with antiviral properties by simply spraying them with aqueous solutions of suitable nanoparticles* and letting them dry. It should also be easy to design cost-effective filters to purify contaminated air and water,” says Professor Vadim Kessler from SLU who has led the work.

The recent COVID-19 pandemic has led to an intense search for new types of treatments and disinfection methods that can be used in outbreaks of viral diseases of this type. One area that has received much attention is nanotechnology, as tiny particles of certain metals and metal oxides have been shown to have anti-viral properties.

Now, researchers from SLU and the University of Tartu in Estonia have studied the outcome when certain types of mineral nanoparticles come into contact with a coronavirus, and they discovered a mode of action that has not been proposed before.

“We now understand what properties such particles need to have to be effective against the coronavirus, and this is a very important step forward,” says Vadim Kessler.

Coronaviruses belong to a type of virus that has an outer envelope, a lipid membrane. It turned out that nanoparticles of sand minerals such as titanium oxide bind very strongly to phospholipids in this membrane. This damages the membrane and leads to the release of viral genetic material, thereby making the virus less able to infect cells.

A major advantage is that this happens at room temperature and that it does not require any kind of activation. Previously, it was believed that mineral nanoparticles could only destroy viruses by producing so-called reactive oxygen species, which would require illumination with UV light.

The study thus suggests that surfaces coated with titanium nanoparticles can destroy enveloped viruses such as coronaviruses and influenza viruses without needing to be activated by UV light, and thus can work in dark spaces. Other small metal oxides that bind strongly to phospholipids, such as iron and aluminum oxides, could work in the same way. Another possible application could be to purify contaminated water in emergencies by adding a nanopreparation and allowing the resulting gel to settle.

“The particles we produce are not dangerous to the human body,” adds Angela Ivask, who is Professor of Genetics at the University of Tartu. “We have tested them on several cell lines to assure this.”

*Nanoparticles are extremely small and can sometimes have properties that are completely different compared to larger particles of the same material.

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

Molecular mechanisms behind the anti corona virus activity of small metal oxide nanoparticles by Björn Greijer, Alexandra Nefedova, Tatiana Agback, Peter Agback, Vambola Kisand, Kai Rausalu, Alexander Vanetsev, Gulaim A. Seisenbaeva, Angela Ivask, and Vadim G. Kessler. Nanoscale, 2025,17, 3728-3738 DOI: https://doi.org/10.1039/D4NR03730H

This paper is open access.

Of musical parodies, Despacito, and evolution

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What great timing, I just found out about a musical science parody featuring evolution and biology and learned of the latest news about the study of evolution on one of the islands in the Galapagos (where Charles Darwin made some of his observations). Thanks to Stacey Johnson for her November 24, 2017 posting on the Signals blog for featuring Evo-Devo (Despacito Biology Parody), an A Capella Science music video from Tim Blais,

Now, for the latest regarding the Galapagos and evolution (from a November 24, 2017 news item on ScienceDaily),

The arrival 36 years ago of a strange bird to a remote island in the Galapagos archipelago has provided direct genetic evidence of a novel way in which new species arise.

In this week’s issue of the journal Science, researchers from Princeton University and Uppsala University in Sweden report that the newcomer belonging to one species mated with a member of another species resident on the island, giving rise to a new species that today consists of roughly 30 individuals.

The study comes from work conducted on Darwin’s finches, which live on the Galapagos Islands in the Pacific Ocean. The remote location has enabled researchers to study the evolution of biodiversity due to natural selection.

The direct observation of the origin of this new species occurred during field work carried out over the last four decades by B. Rosemary and Peter Grant, two scientists from Princeton, on the small island of Daphne Major.

A November 23, 2017 Princeton University news release on EurekAlert, which originated the news item, provides more detail,

“The novelty of this study is that we can follow the emergence of new species in the wild,” said B. Rosemary Grant, a senior research biologist, emeritus, and a senior biologist in the Department of Ecology and Evolutionary Biology. “Through our work on Daphne Major, we were able to observe the pairing up of two birds from different species and then follow what happened to see how speciation occurred.”

In 1981, a graduate student working with the Grants on Daphne Major noticed the newcomer, a male that sang an unusual song and was much larger in body and beak size than the three resident species of birds on the island.

“We didn’t see him fly in from over the sea, but we noticed him shortly after he arrived. He was so different from the other birds that we knew he did not hatch from an egg on Daphne Major,” said Peter Grant, the Class of 1877 Professor of Zoology, Emeritus, and a professor of ecology and evolutionary biology, emeritus.

The researchers took a blood sample and released the bird, which later bred with a resident medium ground finch of the species Geospiz fortis, initiating a new lineage. The Grants and their research team followed the new “Big Bird lineage” for six generations, taking blood samples for use in genetic analysis.

In the current study, researchers from Uppsala University analyzed DNA collected from the parent birds and their offspring over the years. The investigators discovered that the original male parent was a large cactus finch of the species Geospiza conirostris from Española island, which is more than 100 kilometers (about 62 miles) to the southeast in the archipelago.

The remarkable distance meant that the male finch was not able to return home to mate with a member of his own species and so chose a mate from among the three species already on Daphne Major. This reproductive isolation is considered a critical step in the development of a new species when two separate species interbreed.

The offspring were also reproductively isolated because their song, which is used to attract mates, was unusual and failed to attract females from the resident species. The offspring also differed from the resident species in beak size and shape, which is a major cue for mate choice. As a result, the offspring mated with members of their own lineage, strengthening the development of the new species.

Researchers previously assumed that the formation of a new species takes a very long time, but in the Big Bird lineage it happened in just two generations, according to observations made by the Grants in the field in combination with the genetic studies.

All 18 species of Darwin’s finches derived from a single ancestral species that colonized the Galápagos about one to two million years ago. The finches have since diversified into different species, and changes in beak shape and size have allowed different species to utilize different food sources on the Galápagos. A critical requirement for speciation to occur through hybridization of two distinct species is that the new lineage must be ecologically competitive — that is, good at competing for food and other resources with the other species — and this has been the case for the Big Bird lineage.

“It is very striking that when we compare the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major, the Big Birds occupy their own niche in the beak morphology space,” said Sangeet Lamichhaney, a postdoctoral fellow at Harvard University and the first author on the study. “Thus, the combination of gene variants contributed from the two interbreeding species in combination with natural selection led to the evolution of a beak morphology that was competitive and unique.”

The definition of a species has traditionally included the inability to produce fully fertile progeny from interbreeding species, as is the case for the horse and the donkey, for example. However, in recent years it has become clear that some closely related species, which normally avoid breeding with each other, do indeed produce offspring that can pass genes to subsequent generations. The authors of the study have previously reported that there has been a considerable amount of gene flow among species of Darwin’s finches over the last several thousands of years.

One of the most striking aspects of this study is that hybridization between two distinct species led to the development of a new lineage that after only two generations behaved as any other species of Darwin’s finches, explained Leif Andersson, a professor at Uppsala University who is also affiliated with the Swedish University of Agricultural Sciences and Texas A&M University. “A naturalist who came to Daphne Major without knowing that this lineage arose very recently would have recognized this lineage as one of the four species on the island. This clearly demonstrates the value of long-running field studies,” he said.

It is likely that new lineages like the Big Birds have originated many times during the evolution of Darwin’s finches, according to the authors. The majority of these lineages have gone extinct but some may have led to the evolution of contemporary species. “We have no indication about the long-term survival of the Big Bird lineage, but it has the potential to become a success, and it provides a beautiful example of one way in which speciation occurs,” said Andersson. “Charles Darwin would have been excited to read this paper.”

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

Rapid hybrid speciation in Darwin’s finches by Sangeet Lamichhaney, Fan Han, Matthew T. Webster, Leif Andersson, B. Rosemary Grant, Peter R. Grant. Science 23 Nov 2017: eaao4593 DOI: 10.1126/science.aao4593

This paper is behind a paywall.

Happy weekend! And for those who love their Despacito, there’s this parody featuring three Italians in a small car (thanks again to Stacey Johnson’s blog posting),