Bioelution, Bioavailability, and Toxicity of Cobalt Compounds Correlate

Area of Science:

• Environmental Science
• Toxicology
• Materials Science

Background:

• Cobalt substances are vital in numerous technologies, necessitating accurate toxicological prediction.
• Assessing the toxicity of novel or understudied cobalt compounds is essential.

Purpose of the Study:

• To evaluate the correlation between in vitro bioaccessibility and in vivo toxicity of inorganic cobalt substances.
• To identify reliable predictors for cobalt bioavailability and systemic toxicity.

Main Methods:

• Tested 6 inorganic cobalt substances for in vitro bioelution in simulated gastric and intestinal fluids.
• Conducted in vivo blood kinetics, mass balance, and oral toxicity tests (acute and repeated dose).
• Correlated in vitro bioaccessibility with in vivo bioavailability and toxicity outcomes.

Main Results:

• High in vitro bioaccessibility strongly correlated with high in vivo bioavailability and toxicity.
• Low in vitro bioaccessibility correlated with low in vivo bioavailability and toxicity.
• In vitro bioelution in simulated gastric fluid precisely predicted oral repeated dose toxicity differences.

Conclusions:

• In vitro bioelution in simulated gastric fluid is a reliable predictor of in vivo bioavailability and oral systemic toxicity for inorganic cobalt substances.
• Bioelution data facilitate grouping and read-across for hazard and risk assessment of cobalt compounds.
• Solubility, particularly gastric bioelution, serves as a conservative yet valuable tool for evaluating cobalt substance toxicity.