AUTHOR=Huchthausen Julia , König Maria , Escher Beate I. , Henneberger Luise 

TITLE=Experimental exposure assessment for in vitro cell-based bioassays in 96- and 384-well plates

JOURNAL=Frontiers in Toxicology

VOLUME=5

YEAR=2023

URL=https://www.frontiersin.org/journals/toxicology/articles/10.3389/ftox.2023.1221625

DOI=10.3389/ftox.2023.1221625

ISSN=2673-3080

ABSTRACT=<p><italic>In vitro</italic> cell-based bioassays have great potential for applications in the human health risk assessment of chemicals. The quantification of freely dissolved concentrations (<italic>C</italic><sub>free</sub>) in <italic>in vitro</italic> assays is essential to generate reliable data for <italic>in vitro</italic>-to-<italic>in vivo</italic> extrapolation. Existing methods for the quantification of <italic>C</italic><sub>free</sub> are limited to low-throughput microtiter plates. The present study is a proof of principle for the applicability of a solid-phase microextraction (SPME) method for the determination of <italic>C</italic><sub>free</sub> in the peroxisome proliferator-activated receptor gamma (PPARγ) bioassay run in 384-well plates with 80 µL medium per well. The effect concentrations obtained from 384-well plates were compared with those obtained from 96-well plates in a previous study. Nominal effect concentrations obtained using 96- and 384-well plates agreed with each other within a factor of three, and freely dissolved effect concentrations agreed within a factor of 6.5. The good degree of agreement in the results from both plate formats proves the general applicability of the SPME method for the determination of <italic>C</italic><sub>free</sub> for bioassays in 384-well plates, making the present study a first step toward exposure assessment in high-throughput bioassays.</p>