Microfluidic Chip with Integrated Electrophoretic Immunoassay for Investigating Cell–Cell Interactions

Abstract

Microfluidics have been used to create "body-on-chip" systems to mimic in vivo cellular interactions with a high level of control. Most such systems rely on optical observation of cells as a readout. In this work we integrated a cell-cell interaction chip with online microchip electrophoresis immunoassay to monitor the effects of the interaction on protein secretion dynamics. The system was used to investigate the effects of adipocytes on insulin secretion. Chips were loaded with 190 000 3T3-L1 adipocytes and a single islet of Langerhans in separate chambers. The chambers were perfused at 300-600 nL/min so that adipocyte secretions flowed over the islets for 3 h. Adipocytes produced 80 μM of nonesterified fatty acids (NEFAs), a factor known to impact insulin secretion, at the islets. After perfusion, islets were challenged with a step change in glucose from 3 to 11 mM while monitoring insulin secretion at 8 s intervals by online immunoassay. Adipocyte treatment augmented insulin secretion by 6-fold compared to controls. The effect was far greater than comparable concentrations of NEFA applied to the islets demonstrating that adipocytes release multiple factors that can strongly potentiate insulin secretion. The experiments reveal that integration of chemical analysis with cell-cell interaction can provide valuable insights into cellular functions.

A Parallel Perifusion Slide From Glass for the Functional and Morphological Analysis of Pancreatic Islets

“…Furthermore, new processes to fabricate microfluidic channels from glass make this material attractive ( Wang et al, 2018 ). Islet on chip systems made from glass have been successfully fabricated and applied to investigate islet physiology and hormone secretion ( Dishinger et al, 2009 ; Lu et al, 2018 ). However, these systems were only partially made from glass and not ideally customized for parallel multi-parametric live-cell monitoring.…”

“…Nevertheless, pancreas-on-chip systems made from glass described in the literature do not yet combine all these desirable features in a practical system for diabetes research. One reason for that is that these systems are only partially made from glass ( Lu et al, 2018 ; Shik Mun et al, 2019 ). Monolithic glass chips allow for rapid prototyping, show low unselective drug absorption, low autofluorescence and high transparency ( Piruska et al, 2005 ; Schwerter et al, 2016 ; van Meer et al, 2017 ).…”

Microfluidic and Paper-Based Devices for Disease Detection and Diagnostic Research

“…Single islet and adipocytes were loaded in the chip, which resulted in an increase of insulin secretion by the adipocytes. They found that this was due to the release of non-esterified fatty acids, as assessed by electrophoretic immunoassay [ 109 ]. Natural killer (NK) cells act by using cell-to-cell interactions to kill target cells, an approach currently under investigation in cancer cell immunotherapy.…”

Characterization of Microchannel Replicability of Injection Molded Electrophoresis Microfluidic Chips

“…The microfluidic chip is a technology platform that integrates sample preparation, reaction, separation, detection, and other processes by controlling fluid flow in microchannels [1,2,3]. Since the first demonstration in 1990 [4,5], microfluidic chip electrophoresis (MCE) has developed rapidly with important applications in many areas, such as life sciences, biology, medicine, food, and environmental monitoring [6,7,8,9,10]. This method for protein analysis is automated, which allows for rapid separation, and high sensitivities and efficiencies [11,12,13,14,15].…”