Analysis of Reproducibility and Robustness of a Renal Proximal Tubule Microphysiological System OrganoPlate® 3-lane 40 for In Vitro Studies of Pharmacokinetics and Toxicodynamics
Microphysiological systems are a promising new experimental tool for drug and chemical safety evaluation. These models are rapidly evolving, and concerns exist about the reproducibility, robustness and relative benefits when compared to traditional in vitro cultures. This study used OrganoPlate® 3-lane 40, a microfluidics-based model of the renal proximal tubule and compared it to multi-well static cultures using a number of human renal proximal tubule epithelial cell (RPTEC) types. We followed previously published protocols but adapted them to the varying cell proliferation rates of different RPTECs; primary cells required up to 7 days in culture before experiments, while some immortalized cell lines could be used in 3 days. Function of various tubule-specific transporters, permeability of small molecules (cisplatin, tenofovir and perfluorooctanoic acid) and fluorescent dextrans (60-150 kDa), basal and chemical-effected gene expression, and cell viability were tested. Different RPTEC types and culture conditions (OrganoPlate® 3-lane 40 vs multi-well plates) were compared. We found that there are advantages offered by OrganoPlate® 3-lane 40 as compared to multi-well cultures – presence of media flow, albeit intermittent, and fairly high throughput. However, this model appears to offer only limited (e.g., MRP-mediated transport) advantages in terms of either gene expression or transporter function when compared to the multi-well plate culture conditions. It can also be used to study cellular uptake and direct toxic effects of small molecules; still, it may have limited utility for studies of pharmaco-/toxico-kinetics because drug transport between blood and tubule compartments is considerably affected by the gel barrier. Overall design: Comparative gene expression profiling analysis of TempO-Seq data for RPTEC cells using different platforms, cells that over-expressed certain transporter proteins, and chemical treatment conditions.