Novel Blood Purification Technique Eliminates Antibiotic-Resistant Bacteria via Artificial Clots

Extracorporeal hemoadsorption has seen limited success in treating bacteremia, primarily due to the lack of an effective strategy for ensuring bacterial cells are adequately brought into contact with surfaces and the absence of universal substances for capturing bacteria. Now, a newly developed extracorporeal device can remove various intact bacteria from whole blood by utilizing microfluidic bacterial margination and engineered cell-depleted thrombus (CDT) surfaces with bacterial adhesin receptors.

A research team from Ulsan National Institute of Science & Technology (UNIST, Ulsan, South Korea) has introduced a novel blood purification technology that captures and eliminates bacteria from the bloodstream using artificial clot-like surfaces. This device works similarly to dialysis, extracting infected blood from the body, adsorbing bacteria onto the artificial thrombi, and then returning the purified blood to the patient. The technology was developed based on insights into the dynamics of blood flow. In circulating blood, red blood cells, which are flexible, tend to migrate towards the center of the flow, while stiffer platelets are pushed towards the walls of the vessels—a process called margination. The researchers theorized that bacteria, which share similar rigidity to platelets, could be captured using this same mechanism. The device’s design and blood flow parameters were optimized to enhance bacterial margination and removal.

The newly developed extracorporeal blood purification device (eCDTF) incorporates a spiral structure within its central tube, where artificial blood clots are embedded. These artificial thrombi, composed of plasma proteins without any cellular components like white blood cells, attract and trap bacteria flowing through the tube. This innovation could lead to new treatments for life-threatening infections, including sepsis, even those caused by antibiotic-resistant bacteria. According to a study published in the journal Advanced Science, the eCDTF was able to effectively remove over 90% of major pathogenic bacteria, including both Gram-positive and Gram-negative strains such as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), along with antibiotic-resistant strains and bacteria sourced from human feces.

Preclinical testing further confirmed its effectiveness. In experiments with rats infected with methicillin-resistant Staphylococcus aureus (MRSA), just three hours of extracorporeal circulation significantly lowered blood bacterial counts and inflammatory markers. Major organs, such as the liver and spleen, which are common sites for bacterial infection, also showed a marked reduction in bacterial load. Remarkably, while all untreated control rats succumbed within seven days, rats treated once with the device achieved a survival rate of around 33%, and those treated twice had a 100% survival rate.

“This technology can directly eliminate a wide range of pathogenic bacteria without the use of antibiotics, potentially transforming the treatment of bloodstream infections such as bacteremia and sepsis,” said UNIST Professor Joo H. Kang who led the research team. “If not treated promptly, bloodstream infections can escalate into sepsis, causing widespread inflammation and organ failure. Our device offers a promising new approach to intervene early and effectively.”

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