Using Cell Lensing and Nanosensor Chemical Cytometry to Characterize the Efflux Heterogeneity of Immune Cell Populations

Cellular immune heterogeneities play a critical role in the progression and prevention of cardiovascular or neurodegenerative diseases. Thus, a tool that can profile the dynamic antigenic responses of different immune cell populations in terms of their chemical efflux and biophysical properties can enhance our understanding of past and future unknown microorganisms and diseases. Herein, we have developed a technique called Nanosensor Chemical Cytometry (NCC), that utilizes an optical nanosensor array embedded within microfluidics to interrogate chemical species efflux from individual cells in real-time. The NCC technique takes advantage of the cell itself as an informative Gaussian lens, projecting both the nIR emission of the single-walled carbon nanotube sensors as well as various cellular physical properties. Different nanosensor integration methods were investigated to optimize the signal readout.<br/><br/>Using the NCC technique, we have profiled both the heterogeneity of nitric oxide (NO) efflux from macrophage populations and hydrogen peroxide (H₂O₂) efflux from monocyte populations. The technique was able to profile immune heterogeneities at attomolar sensitivity in a completely non-destructive and real-time manner with a throughput rate of ~600 cells/hr. In addition, new phenotype correlations between real-time extracellular immune responses and multiple biophysical properties (cell size, eccentricity, RI) of cell populations were investigated with exact numerical values and distribution statistics. This work provides an efficient strategy for the chemical analysis of cell populations in manufacturing and biopharmaceutical engineering.