Abstract

Automated 3D Cell-Based Assays Using a Novel Flowchip System

Evan Cromwell, President & CEO, Protein Fluidics

There is an increasing interest in using three-dimensional (3D) cell structures for modeling tumors, organs, and tissue to accelerate translation research. Significant progress has been made in formation of such structures to recapitulate the in vivo environment but performing complex assays with them can be challenging.  Organoids can be subject to loss or damage from pipettes during common steps such as media exchange, supernatant sampling, or immunofluorescence staining.  We present here results from automated organoid assays using a Pu·MA System for research in oncology therapeutics, single organoid secretion, and metabolite sampling.  The system uses a novel flowchip that contains organoid samples connected to multiple reservoirs via microfluidic channels.  Assay reagents are transferred in and out of the sample well without loss of or damage to the organoids.  The bottom of the sample chamber is thin optically clear plastic compatible with high resolution fluorescence imaging.  The whole system can be kept in an incubator allowing long term cellular assays to be performed.  In a first example, effects of anti-cancer drugs on cancer spheroids were assayed using high content imaging.  Confocal imaging allowed 3D resolution of spheroid structures and complex analysis of cytotoxic effects.  In addition, conditioned media was removed and analyzed for VEGF.  In a second example, triple negative breast cancer (TNBC) patient-derived organoids were used for disease modeling.  This novel assay system using microfluidics enables automation of 3D cell-based cultures that mimic in vivo conditions, performs multi-dosing protocols and multiple media exchanges, provides gentle and convenient handling of spheroids and organoids, and allows a wide range of assay detection modalities.