Event Abstract Back to Event Evaluation of an interleukin-8 conjugated extracorporeal neutrophil reprogramming device for the treatment of acute inflammatory disorders Alexander Malkin1, 2, Kai Singbartl3, John A. Kellum2, 4 and William J. Federspiel1, 2, 4, 5 1 University of Pittsburgh, Department of Bioengineering, United States 2 University of Pittsburgh, McGowan Institute for Regenerative Medicine, United States 3 Penn State Hershey, Department of Anesthesiology, United States 4 University of Pittsburgh, Department of Critical Care Medicine, United States 5 University of Pittsburgh, Department of Chemical Engineering, United States Introduction: As one of the first responders to sites of inflammation, neutrophils play a critical role in the progression of acute inflammatory conditions such as sepsis. High quantities of neutrophils migrating to remote organs such as the lungs has been associated with increased morbidity and mortality by initiating multiple organ dysfunction or immune paralysis in septic patients. The migration and activation of neutrophils is regulated by CXCR-1 and CXCR-2, g-protein coupled receptors that bind to interleukin-8 (CXCL-8) [1]. It is hypothesized that exposure to high levels of immobilized CXCL-8 within an extracorporeal device will attenuate neutrophil migratory response. In this study, a method for immobilization of CXCL-8 on the inner lumen of AN69 dialyzer fibers was developed and constructed into a prototype extracorporeal device. Additionally, the device was evaluated by measuring CXCR-1 and CXCR-2 neutrophil surface receptor expression after human blood perfusion. Materials and Methods: First, amine modified AN69 dialyzer fibers (Gambro) were potted into a polycarbonate housing. Module ends were trimmed to open the fiber inner lumen. An NHS activated polyethylene-glycol spacer was immobilized on the inner lumen. CXCL-8 was then conjugated using NHS/EDC linkage. A control module used bovine serum albumin in place of CXCL-8. Fresh human whole blood was recirculated through the device for 90 minutes. A positive control was created by adding 1ug/ml soluble CXCL-8 to whole blood. Blood samples were collected at 45 and 90 minutes for analysis of CXCR-1 and CXCR-2 expression using flow cytometry. Results and Discussion: The soluble CXCL-8 positive control induced 24% and 94% downregulation of CXCR-1 and CXCR-2 respectively when compared to baseline blood, indicating complete migratory shutoff [2]. In the CXCL-8 modified module, neutrophil surface receptor expression of CXCR-1 and CXCR-2 decreased by 50% and 90%. CXCR-2 downregulation in this module closely tracked the positive control, indicating change in neutrophil migratory phenotype. The BSA modified control module induced less than 10% variation from baseline blood, demonstrating downregulation in the CXCL-8 module was due to the immobilized chemokine. Conclusion: An effective method for immobilization of CXCL-8 on the inner lumen of AN69 dialyzer fibers was developed. Furthermore, the CXCL-8 modified prototype module induced downregulation of CXCR-1 and CXCR-2 neutrophil surface receptors when perfused with human whole blood. Functionally, it is anticipated that CXCR-1 and CXCR-2 downregulation will reduce neutrophil migration and associated damage in acute inflammatory disorders. Further testing is being conducted to evaluate the functional response of reprogrammed neutrophils to a chemotactic gradient. Gambro Industries for supplying amine functionalized dialyzer fibers