48th LaMer Special Seminar is going to be held on June 23, 2023.

Date:  June 23, 2023

Time: 14:30 – 15:30 p.m., Online

■Title：High-throughput exposure assessment in cell-based in vitro bioassays

■Lecturer：Luise Henneberger,Ph.D.

                 Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ,

                 Leipzig, Germany 

Admission is free. If you would like to attend, please register in advance using the link below.

After registration, you will receive an e-mail confirming your participation in the seminar.

https://us06web.zoom.us/meeting/register/tZUsceqhqj0iEtGLCYdPCmlrJL0X9hnDJKoO

Abstract:

The chemical dose in cell-based in vitro bioassays is subject to various degradation and loss processes such as volatilization, binding to and reaction with cell culture medium components, diffusion into well plate plastics and cellular uptake and metabolism. Consequently, the nominal concentration added to the assay system may differ by orders of magnitude from the effective concentration. The freely dissolved concentration in the assay medium (C_free) is considered a better dose metric and various in vitro exposure (disposition) models have been developed to calculate C_free. Recently, our group has also implemented a automated method for experimental determination of C_free in 96-well plate format to overcome several limitations of existing in vitro exposure models related to chemicals that show non-linear protein binding or that are degraded during the bioassay. The approach uses a commercially available 96-pin solid-phase microextraction device and can be applied to a broad range of test chemicals from hydrophilic to hydrophobic and from neutral to ionizable organic chemicals including also perfluoroalkyl substances (PFAS) and chemical mixtures. This seminar will introduce you to the working principle of the method and how it can be applied to measure C_free in bioassay medium aliquots, plasma protein binding and degradation rate constants of unstable test chemicals. The usefulness of high-throughput exposure assessment will be further demonstrated in two recently conducted case studies with (I) highly protein-bound chemicals (PFAS) and (II) reactive chemicals (acrylamides).

Biography:

Dr. Luise Henneberger leads the team “Bioassay exposure assessment” in the Department of Cell Toxicology at the Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany. After finishing her diploma in food chemistry at the Martin Luther University Halle-Wittenberg in 2012, Luise was working as a research assistant and later as a PhD student at the UFZ in the Department of Analytical Environmental Chemistry. Her dissertation focussed on the equilibrium sorption of ionogenic organic chemicals (IOCs) to selected proteins, like serum albumin and structural protein. From 2015-2020 she was working in the Department of Cell Toxicology in two industry-funded research projects on the improved quantitative exposure assessment in cell-based bioassays and the development and implementation of methods for quantitative in vitro-to-in vivo extrapolation (QIVIVE).