FDA Postdoctoral Fellowship - Metabolic Activation of Nitrosamine Impurities

About the role

The FDA Office and Location: A research opportunity is available immediately with the Food and Drug Administration (FDA), The National Center for Toxicological Research (NCTR) located in Jefferson, Arkansas.

Research Project

This fellowship will focus on investigating the metabolism of nitrosamine drug substance-related impurities (NDSRIs) and its potential impact on mutagenicity and carcinogenicity to address critical FDA regulatory knowledge gaps regarding drug safety. You will collaborate with an interdisciplinary team of scientists to elucidate metabolic activation pathways of structurally complex NDSRIs, with a particular emphasis on DNA adduct formation, using in vitro metabolic systems and mammalian cell models. These studies will provide mechanistic insights into the structure-activity relationships underlying the mutagenic and carcinogenic potency of NDSRIs. The research activities will also support improvements in (quantitative) structure-activity relationship ([Q]SAR) modeling and enhance the FDA’s ability to conduct regulatory safety assessments of NDSRIs in affected drug products.

Learning Objectives

• Under the guidance of the mentor, you will receive hands-on training in mechanistic study design, experimental execution, and systematic evaluation in the fields of drug metabolism and chemical carcinogenesis.
• Educational activities will include:
• Gaining experience with in vitro metabolism studies using liver S9 fractions, microsomes, and mammalian cell culture systems.
• Learning to characterize major intermediates and metabolites using high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and/or proton nuclear magnetic resonance spectroscopy (1H-NMR).
• Developing skills in the identification and quantification of DNA adducts formed by NDSRIs in S9/microsomal incubations with DNA and in cell culture systems, using 1H-NMR and LC-MS/MS.
• Presenting research findings at scientific conferences and publishing results in peer-reviewed journals.

Mentor

The mentor for this opportunity is Qiangen Wu (qiangen.wu@fda.hhs.gov). If you have questions about the nature of the research, please contact the mentor.

Anticipated Appointment Start Date

October/November 2026. Start date is flexible and will depend on a variety of factors.

Appointment Length

The appointment will initially be for one year, but may be renewed upon recommendation of FDA and is contingent on the availability of funds.

Level of Participation

The appointment is full time.

Participant Stipend

The participant will receive a monthly stipend commensurate with educational level and experience.

Citizenship Requirements

This opportunity is available to U.S. citizens, Lawful Permanent Residents (LPR), and foreign nationals. Non-U.S. citizen applicants should refer to the Guidelines for Non-U.S. Citizens Details page of the program website for information about the valid immigration statuses that are acceptable for program participation.

Qualifications

• The qualified candidate should be currently pursuing or have received a doctoral degree in the one of the relevant fields.
• Degree must have been received within the past five years, or anticipated to be received by 12/31/2026.
• I am a U.S. citizen, or I have lived in the United States for at least 36 out of the past 60 months. (36 months do not have to be consecutive.)
• I have read the FDA Ethics Requirements.