[A DC-iDEP-based fast and high-resolution method for detection of LPS tolerance of RAW264.7 macrophages and screening of therapeutic agents].

Sepsis is a leading life-threatening problem in intensive care medicine. The recent studies have given insights into the transition from inflammation to long-term immunosuppression in sepsis. This condition might cause physiological changes that comprise the lipopolysaccharide (LPS) tolerance. Most studies about the LPS tolerance focus on the reduced ability of macrophages to secrete pro-inflammatory cytokines. Although this method has identified various molecular changes, it remains ambiguous since changes in the whole cell population are measured as an average and markers are required for cell recognition. A fast and label-free method is in demand to detect cell tolerance and screen therapeutic agents that might reverse the process. In this study, direct current insulator-based dielectrophoresis (DC-iDEP) was used to characterize the biophysical properties (EKMr) of inflamed cells, LPS-tolerant cells, and cells treated with therapeutic agents. The results showed that the EKMr of these cells was 4.28×10⁸, 3.13×10⁸, and 4.25×10⁸ V/m², respectively, suggesting that the established method was useful in distinguishing LPS-tolerant cells. The device holds the promise to be applied in medical diagnosis and medicine screening.