Capillary-assisted microfluidic biosensing platform captures single cell secretion dynamics in nanoliter compartments

Publication date: Available online 19 February 2020Source: Biosensors and BioelectronicsAuthor(s): Amin Hassanzadeh-Barforoushi, Majid Ebrahimi Warkiani, David Gallego-Ortega, Guozhen Liu, Tracie BarberAbstractCancer cells continuously secrete inflammatory biomolecules which play significant roles in disease progression and tumor metastasis toward secondary sites. Despite recent efforts to capture cancer cells' intercellular secretion heterogeneity using microfluidics, the challenges in operation of these systems as well as the complexity of designing a biosensing assay for long-term and real-time measurement of single cell secretions have become grand research barriers. Here, we present a new capillary-based microfluidic biosensing approach to easily and reliably capture ∼500 single cells inside isolated dead-end nanoliter compartments using simple pipette injection, and quantify their individual secretion dynamics at the single cell resolution over a long period of culture (∼16 h). We first present a detailed investigation of the fluid mechanics underlying the formation of nanoliter compartments in the microfluidic system. Based on the measurement of single cell capture efficiency, we employ a one-step FRET-based biosensor which monitors the single cancer cells' protease activity. The sensor reports the fluorescent signal as a product of amino acid chain cleavage and reduction in its quenching capability. Using the single cell protease secretion data, we identified mo...
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research