Although the pandemic seems to be fading from our memories, millions of people are still affected by COVID-19! Today, it is estimated that around 65 million people suffer from long COVID. Nearly four years after the first cases, evidence on the causes of long COVID is rapidly accumulating through research and leads to treatments. However, numerous treatment trials are ongoing and promising results are already being achieved.
Another fact is that people experience different prolong COVID symptoms. Therefore, it is expected that no single approach to treatment will work for everyone. Perhaps the solution to this is personalized medicine...
There are still many questions left to be answered: Could low levels of certain hormones explain fatigue and brain fog? Could the persistence of the virus help us understand what's really going on? Is there a way to protect ourselves from long COVID?
A few months after SARS-CoV-2 began spreading around the world in early 2020, reports began to emerge that some people were experiencing persistent symptoms. The term "long COVID" was first coined in May 2020. Symptoms of long COVID include more than 200 symptoms, ranging from headaches, brain fog, fatigue or weakness after even a small amount of activity, to depression and gastrointestinal issues. Since then, much has become clear about this once mysterious condition, but researchers still have a long way to go. A study conducted in October of this year by Paul Elliott of Imperial College London, which followed more than 242,000 adults, found that the average duration of symptoms of COVID-19 infection was 1.3 weeks. This seems to be consistent with many previous analyses that show most people recover within a few weeks. However, it was found that 67.5% of the patients continued to have symptoms after 12 weeks and 5.2% after one year. On the other hand, a study conducted in Switzerland followed 1,106 unvaccinated adults who caught SARS-CoV-2 and found that 22.9 of the participants still had long COVID symptoms after 6 months and 617.2 after 2 years.
It is estimated that approximately 200 million people will experience long COVID in the next decade, almost equal to the number of people who currently have heart disease. However, it is also known that the risk of long COVID is associated with the virus variant. For example, approximately 11% of people infected with the old delta variant and 4.5% of those infected with the omicron variant that started spreading in late 2021 experience long COVID.
Women are also at higher risk of developing long COVID than men, as are unvaccinated people and people with pre-existing conditions like asthma and rheumatoid arthritis. Scientists are also considering genetics as a factor. To investigate this, researchers compiled data from 24 studies that included about 6,500 people diagnosed with long COVID, along with more than a million participants as controls. In an analysis that combined data from 11 of these studies, the researchers identified a specific region of the genome that they believe is associated with a roughly 1.6-fold higher chance of developing long COVID. This segment of DNA is located near a gene called FOXP4, which is active in the lungs and other organs.
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Tiny robots made from human cells heal damaged tissue
Scientists have developed tiny robots made from human cells that can repair damaged nerve tissue. These tiny robots, called "Antrobots" and made using human tracheal cells, are thought to be used in personalized medicine in the future.
Michael Levin, a developmental biologist at Tufts University and the leader of the study, made the first robots four years ago. He and his colleagues combined embryonic heart and skin cells from the African clawed frog (Xenopus laevis) to create tiny robots that can crawl and even swim, with tiny cilia and move back and forth. However, these robots, called xenobots, have limited application in medicine because they are not derived from human cells and therefore the human immune system would reject such amphibian-based biorobots.
So, Levin's doctoral student, Gizem Gümüşkaya, began the new study with cells lining the trachea, obtained from anonymous donors of varying ages and genders.
The researchers focused on these types of cells because they are relatively easy to access because of their work on COVID-19 and lung disease, and more importantly, they believe they can be made mobile. Tracheal cells are covered in hair-like projections called cilia that sway back and forth. These projections help the cells push out small particles that usually enter the lungs' airways.
The researchers also planned to use the cells' structures as tiny paddles to power and move the organoid.
Gümüşkaya created a rat-made model of the tracheal cells, which is similar to the microenvironment in the body, where cell-cell interactions take place. After two weeks, the cells had multiplied and formed small spheres, but the cilia were inside the spheres and therefore could not be used for movement. The researchers then grew the cells in a less viscous solution for a week. This solution had certain properties that made the cilia point outward. These cilia acted like oars on a boat for the tiny spheres. The researchers found that some of the anthrobots, each containing several hundred cells, swam in straight lines, some in circles or arcs, and some moved erratically.
To test the therapeutic potential of the anthrobots, Levin and his colleagues placed a few of them in a small petri dish. There, the anthrobots came together to form a "superrobot." The researchers placed this super robot on a layer of damaged nerve tissue. The layer of neurons under the super robot healed completely within three days. Gizem Gümüşkaya says this is surprising because the antrobot cells perform this repair function without requiring any genetic modification. Levin, Gümüşkaya and their colleagues, who published their work in the journal Advanced Science on November 30, think that in the future, antrobots made from a person's own tissue, with or without genetic engineering, could be used to open blood vessels, break down mucus or deliver drugs. By combining different types of cells and exploring other stimuli, it will also be possible to develop robots made from biological materials, which have potential applications even in sustainable construction and space exploration.