High-throughput metabolic toxicity screening using magnetic biocolloid reactors and LC-MS/MS

Area of Science:

• Biochemistry
• Toxicology
• Analytical Chemistry

Background:

• Genotoxicity screening is crucial for chemical safety assessment.
• Existing methods can be costly and time-consuming.
• Metabolic activation is key to understanding chemical-induced DNA damage.

Purpose of the Study:

• To develop an inexpensive, high-throughput genotoxicity screening method.
• To utilize magnetic particles as biocolloid reactors for chemical bioactivation and DNA adduct formation.
• To couple this method with liquid chromatography-mass spectrometry for sensitive adduct detection.

Main Methods:

• Magnetic particles coated with cytosol/microsome/DNA films were used in a 96-well plate format.
• Enzymes within the films bioactivated chemicals, forming reactive metabolites.
• Metabolites covalently bound to DNA, forming nucleobase adducts, which were analyzed by LC-MS/MS.

Main Results:

• The method successfully identified major DNA adducts from ethylene dibromide, N-acetyl-2-aminofluorene, and styrene.
• DNA adduct formation rates correlated well with the rodent genotoxicity metric TD(50).
• Magnetic particles facilitated rapid sample preparation and analysis.

Conclusions:

• This novel method offers a cost-effective and high-throughput approach for genotoxicity screening.
• It provides valuable chemical structure information complementary to traditional toxicity bioassays.
• The technique shows promise for early-stage chemical safety evaluation and drug development.