In what could be next crucial discovery, scientists from the US have developed a new, high-tech device that can clear infections from blood, even those caused by unknown pathogens.
Researchers suggests that the technology was inspired by the human spleen, and it can get rid the blood of nearly every infection from Escherichia coli to Ebola. The research findings are published in the journal Nature Medicine.
Blood Infections and Sepsis:-
Blood infections are extremely difficult to treat and can lead to sepsis – an extreme immune response that can be fatal. Sepsis occurs when a patient’s immune system overreacts to a bloodstream infection, triggering a chain reaction that can cause inflammation, blood clotting, organ damage, and death. It can arise from a variety of infections, including appendicitis, urinary tract infections, skin or lung infections, as well as contaminated intravenous lines, surgical sites, and catheters.
More than half of the time, doctors don’t know what causes these blood infections, and they have to rely on broad-scale antibiotics in an attempt to treat the original infections.
Identifying the specific pathogen responsible for sepsis can take several days, and in most patients the causative agent is never identified. If doctors are unable to pinpoint which types of bacteria or fungi are causing the infection, they treat sepsis patients empirically with broad-spectrum antibiotics but these often fail in many cases and they can have devastating side-effects. This isn’t always effective, and can lead to antibiotic resistance.
New artificial “bio-spleen”, developed by a team of researchers led by Donald Ingber from Harvard University’s Wyss Institute for Biologically Inspired Engineering in Boston, promises to filter the blood and get rid of these infections more effectively.
How it works?
The device’s power lies in a special, magnetic-nanobead filter. To create the filter, the scientists took magnetic nanobeads and coated them with a modified version of a protein called mannose-binding lectin (MBL). This protein is found in humans and it binds to sugar molecules on the surface of more than 90 different bacteria, viruses and fungi, including the toxins that dead bacteria release, which can trigger sepsis.
As a patient’s blood passes through the bio-spleen, these MBL-coated magnetic nanobeads bind to the majority of pathogens. A magnet in the artificial spleen then pulls the beads and the bacteria and viruses they’re attached to out of the blood, leaving the blood purified and ready to be pumped back into the patient.
The device has now been tested on rats infected with either E. coli or Staphylococcus aureus. Five hours after infection, 89% of the rats whose blood had been filtered through the bio-spleen were still alive, compared to only 14% of those who were not treated. Impressively, the scientists found that the device had removed more than 90% of the bacteria from the rats’ blood.
Scientists also found that, the rats whose blood had been filtered also had less inflammation in their lungs and other organs, suggesting they would be less prone to sepsis.
The team then tested the bio-spleen on five litres of blood, which is the volume in the average human being and found that within five hours, the device could remove most pathogens.
According to Dr. Ingber the degree of efficacy of this device is probably enough to control an infection. Once the bio-spleen has removed most pathogens from the blood, antibiotics and the immune system can fight off remaining traces of infection such as pathogens lodged in the organs.
Research team added that, the bio- spleen could also be used to treat viral infections such as HIV and Ebola, and testing as now begun in pigs.
Dr. Nigel Klein, an infection and immunity expert at University College London in the UK, suggests that he expects the bio- spleen could be trialled in humans within a couple of years.