EU Science Hub

Special issue of Toxicology in Vitro dedicated to a late JRC colleague

Schematic representation of the fate processes within an in vitro test system
©EU, 2017
Dec 21 2017

JRC scientists have commemorated their late JRC colleague, Dr Jose-Manuel Zaldívar Comenges, by publishing a series of six papers on the Virtual Cell Based Assay a special issue of the journal Toxicology in Vitro.

The virtual cell based assay (VCBA) is a mathematical model that simulates the time-dependent fate and effects of chemicals in an in vitro test system. It can be used to support the design and interpretation of in vitro toxicity studies, and to improve the safety assessment of chemicals without the need for animal testing. The VCBA was originally developed by Dr Jose-Manuel Zaldívar Comenges, a senior scientist at the JRC, who sadly passed in 2012 following a period of illness. Subsequently, JRC scientists and partners in the EU funded COSMOS project extended the original VCBA model, and evaluated its applicability in toxicology and chemical safety assessment.

The VCBA is an integrated model composed of:

  • a) a fate and transport model;
  • b) a cell partitioning model;
  • c) a cell growth and division model; and
  • d) a cell toxicity and effects model.

It simulates the free concentration of a chemical in the in vitro test medium, taking into account processes such as protein and lipid binding, evaporation, and migration to plastic. It also simulates the concentration reaching cellular compartments, and the resulting effects on cell growth and division (and thus cell toxicity).

The VCBA can be integrated with physiologically based kinetic (PBK) models to extrapolate effects observed in vitro to the whole organism, thereby contributing to the chemical risk assessment of chemicals.

The special issue on the VCBA consists of six papers, which follow a tribute to Dr Zaldívar Comenges.

The biophysical and mathematical foundations of the original VCBA are described in the first paper (Zaldívar Comenges et al.), and various extensions such as the inclusion of additional cellular compartments are described in the second paper (Worth et al.).

Practical applications of the VCBA in toxicology and chemical safety assessment are described by Paini et al in the third and fourth papers.

Since the development of automated software tools is an important step in harmonising and expediting the chemical safety assessment process, the VCBA has been implemented into a KNIME workflow, as described in the fifth paper by Sala Benito et al. 

In the sixth and final paper, Graepel and Lamon et al. take stock of progress in the development and application of VCBA, and offer a perspective for the future.

 

Read more in:

JRC wide hidden block