Published on Monday June 7, 2010
Researchers from Drexel University and the University of Brighton in the U.K. have reported the complete removal of TNF-α, IL-1β, and IL-6, three of the proteins responsible for sepsis, from human blood, in a paper published online in Biomaterials. Authors include Yury Gogotsi, Trustee Chair Professor, and former members of his Nanomaterials Group, Saujanya Yachamaneni, Gleb Yushin, and Sun-Hwa Yeon.
Sepsis is a major health threat, with a mortality rate of 40-80%. Sepsis occurs when proteins called cytokines (IL-1β, IL-6, IL-8, and TNF-α), released by the immune system in response to infection, create an intense state of systemic inflammation, which damages healthy tissue and can lead to organ failure. The annual incidence of sepsis has been estimated at 400 thousand cases in the United States and 20 million cases worldwide. The absence of efficient drug-based therapies makes this physiological response to infection one of the major burdens of healthcare systems, costing over €7.6 billion and $17 billion per year in Europe and the U.S., respectively.
Few sepsis treatments have reported significant effects on cytokine plasma concentrations. Alternative methods of selected inflammatory cytokine removal, such as continuous hemofiltration and hemodiafiltration, have been studied over the last few decades. In vitro continuous plasma filtration coupled with adsorption by charcoal, various resins, and carbonized powders, have achieved the removal efficiency of IL-1β, IL-6, and IL-8 in the range of 94-100%. However, the concentration of TNF-α, which has larger molecular dimensions than others, could only be decreased by 20-80% because the membranes or adsorbents used were not specifically designed to maximize adsorption.
The U.S./U.K. team has developed an innovative method that allows the creation of carbon adsorbents with the desired pore size. This method uses selective etching of inorganic crystalline carbides to produce "carbide-derived carbons" (CDC). Previous results obtained by the Drexel/Brighton team using this method indicated 100% removal of IL-1β, IL-6, and IL-8, and 92% removal of TNF-α within one hour (Biomaterials, 27 (2006) 5755).
Now, by adjusting the surface chemistry and starting particle size of the carbide material (Ti2AlC), the team reports removal of TNF-α at a rate of 99.7-100%. The nano-engineered adsorbents with a tailored porosity outperformed any other materials or methods in the efficiency of cytokine adsorption.
This technology has been transferred to Y-Carbon, Inc., which is developing tunable nanoporous materials for high-performance industrial and commercial application.