Standardization of Intratracheal Instillation Study of Manufactured Nanomaterials

Abstract

Intratracheal (IT) instillation is a useful method for screening and hazard identification of inhaled materials, including manufactured nanomaterials. However, many variables regarding sample preparation, experimental equipment, and technical procedures influence results from studies involving IT instillation, and a standard procedure has not yet been validated internationally. These drawbacks prevent accurate comparison of hazard information obtained from different test facilities. In this chapter, we summarize representative IT instillation procedure and present acceptable ranges at which various procedural components do not affect the results. Issues requiring consideration prior to experimentation include the preparation of the dose suspension, appropriate vehicle, and delivery device. In addition, practical aspects of the testing procedure including appropriate forms of anesthesia, animal positioning during IT instillation, intubation methodology, and dosing volume, rate, and frequency are addressed, and recommended endpoints for hazard identification are described. Furthermore, an example recommended procedure for reproducible IT instillation is provided. Technical guidance for reproducible procedures, e.g., a Standard Operating Procedure, is pivotal for the standardization of IT instillation studies, and this chapter contributes validated technical information. In conclusion, IT instillation is poised to occupy an important position regarding hazard screening of manufactured nanomaterials.