Panagiotis Kastritis, Greek scientist who revolutionized cryogenic electron microscopy

The President of Hot4Cryo talks about the latest technology that is now also coming to Greece.

For most people outside biology and related academia, the term cryo-electron microscopy logically means nothing at all. Let's look at it in rough lines.

Cryogenic electron microscopy is a modern technology that allows scientists to view specimens that have been cooled to extremely low temperatures, with great precision, in order to preserve their structure.

doctor. Panagiotis Kastritis is an assistant professor of “Cryo Electron Microscopy of Membrane Protein Complexes” at the Institute of Biochemistry and Biotechnology at Martin Luther University in Germany and also a research associate at the Institute of Chemical Biology of the National Research Foundation. Talk to the reader.

As of March 2023, he is also Head of the European Hot4Cryo programme, worth €2.5 million, the ultimate goal of which is to bring this technology for the first time to Greece and more generally to South-Eastern Europe. To be more precise, to transfer knowledge of the use of this technology and in our country.

This specific funding is highly competitive and is offered exclusively to world-renowned scientists in order to transfer technologies to “developing” countries in the EU, which currently includes Greece, due to the protracted crisis. Let's take things from the beginning.

What is a cryogenic electron microscope?

“This particular technology helps us take images with tremendous resolution, meaning thanks to it you can see not only cells and their structure, but even individuals.”

This was basically one of the first things Mr. Castretz said to me as he tried to explain to me what this previously unknown technology was to which he had devoted a large part of his life.

But how long has this technology been around?

“The electron microscope technique is a very old method. It was born in Germany in the 1930s, and thanks to it we know what we know about cells and how they are structured. Just think of the pictures of cells in biology textbooks.”
So far so good, but how is a cryogenic electron microscope different from a pure electron microscope? “Cryo electron microscopy is a more modern method. In this you freeze your sample in order to preserve its structure. The electrons have very high energies and destroy the sample. So if you freeze it, the damage will be much less. Quite simply because the electrons are interacting with a solid and not with “Liquid. So you're basically protecting her.”

The result is that this revolutionary technological method provides us with more accurate imaging of our samples. In order to have scale and impact in various fields, this particular technology won the Nobel Prize in Chemistry in 2017.

Before continuing with the rest, let us assume that Panagiotis Kastritis studied and obtained his degree from the Biology Department of the National University and Kapodistria University in Athens. He went outside to take some measurements, and reality finally kept him there, even if it wasn't in his plans. He now runs his laboratories in Germany and at the National Research Foundation.
It focuses on studying how molecules inside the cells of living organisms interact, and these interactions determine the function of the cell. I asked him if he would be able to do the things he does today if he had stayed in Greece.

“What we do abroad, at least, we cannot do in Greece. If that happens, it will only be done through partnerships. But this method also concerns me, I who live abroad and alone cannot do anything I do.” And here he tells me something very interesting that we tend to forget when we think science works other times.

“Research is no longer a researcher working in a lab 24 hours a day in shifts waiting to get the perfect results and making a breakthrough out of nowhere to get a Nobel Prize. Research is now an incredibly collaborative process. You have to be communicative, talking to people, until you get a response.” For all these ideas and find people who will work with you.”

The Hot4Cryo?

We return to the cryogenic electron microscope and its relationship to Greece. In order to proceed with this process, expensive tools are needed that are installed in specially designed spaces. As you understand from the context, these tools do not exist either in Greece or in the wider region of southeastern Europe. This is where Mr. Kastritis and the Hot4Cryo project come in.

“At the moment, there are no such microscopes in Greece nor in Southeastern Europe in general, but they will come because the management of the National Research Foundation has requested significant funding. Therefore I am responsible for bringing knowledge from Germany, establishing the electron microscope laboratory and training scientists to become experts in this “In the same way,” Mr. Castretz tells me.

“The European Environment Institute, a unique research centre, received this funding from the Greece 2.0 project and the European Investment Bank,” he adds. With the money it received, EIE chose to renovate the building (it is a particularly impressive building, but it dates back to 1958) but also to invest in Modern and unique research equipment. Both the refurbishment and the equipment include microscope rooms as well as the microscopes themselves.

Cryogenic electron microscopes at the Castretz Laboratory in Germany. EIE will bring the latest generation of this type of microscopes to Greece. | © Castritis Laboratory, 2024

What is the point of Hot4Cryo in writing?

“The first goal is to accelerate the integration, installation and use of the cryogenic electron microscopes that will enter the EIE. The second goal is to communicate the project, so that scientists in Greece and abroad can come and measure their samples in the selected cryogenic electron microscopes. The main goal is one: to conduct pioneering and competitive biological research on “Global level.”

Benefits of technology in our daily lives

Let's see again what the cryogenic electron microscope offers us? “The applications are so many. Just think that all the images that exist to understand how a cell is built are from this method. This method provides us with very basic knowledge of cell and structural biology. In other words, what the 3D cytoskeleton looks like, that is, it helps us understand what matter is.” “

The advancement of knowledge about matter is, and should be, an end in itself for sciences like biology. At the same time, of course, there are also very specific applications. “The most important example I can give you is the coronavirus. We were hearing different things about the claim that there is no coronavirus. So we took samples and saw the virus. All these illustrations that are on the Internet or that appear in the media are based on scientific data mainly from electron microscopy.” “Right now, we know the structure of the coronavirus in tremendous detail.”

“So, if you know how the two pieces of the puzzle fit together, you can also take them apart. So electron microscopy helps understand structures during infection. Knowing this, we design drugs that prevent the virus from entering our cells.” Applications can also be found in biotechnology and many other fields. In fact, computing plays a big role in our data analysis: since we analyze tens of thousands of images in each experiment, it requires huge storage space (on the order of petabytes), modern graphics cards, and the latest hardware. Latest machine learning/artificial intelligence algorithms.

At the conclusion of our discussion, having understood much more than I expected when I first saw the term, I asked Panagiotis Kastritis if there was anything he would like us to add. He wanted to emphasize once again that scientific research is now a much more collaborative process than we think. The cryogenic electron microscope itself is a very good example because imaging a substance with great resolution is a very important step in understanding its function.

Image source: Castrets Laboratory, 2024