The Institute of Environmental Science (CML) at Leiden University is looking for an enthusiastic and highly motivated PhD-candidate who is eager to study the ecotoxicological safety of nano-embedded medicines and their degradation products.
Description of research:
The application of nanotechnology in medicine, provides tremendous opportunities either to improve existing therapies or enable entirely new treatments for a range of debilitating diseases, including cancer and genetic disorders. Especially in the field of drug delivery, nanomedicines (NM) have shown effectiveness by increasing the therapeutic index of existing drugs or enabling macromolecular drugs to overcome biological barriers. Despite these success stories, there are still quite some roadblocks that limit the full potential and breadth of NM in treating a variety of diseases. From the perspective of (eco)toxicology we are talking mainly about substances that are problematic in light of their poor degradability, high toxicity or tendency to accumulate at non-targeted sites. The Environmental Risk Assessment framework developed within our group gives tools to determine exposure as well as potential effects, allowing risk characterization.
What you will do:
We will establish a workflow for the investigation of the release and potential short-term and long-term impacts of nanomedicines and their degradation products on a representative battery of non-target species (e.g. culturable microbes from a representative host, some standard low tier laboratory species like daphnids, algae). Experiments on fate within the relevant exposure medium, as well as uptake and effects will be executed. The assessment will follow a tiered approach adding realism and complexity into the testing: from standard OECD lab tests to disentanglement of mechanisms of toxicity including biotransformation and degradation of nanomedicines towards a quantitative assessment with more complex testing, enhancing the human and ecological relevance. This tiered approach gives support to environmental risk assessment for these new classes of medicines from the design phase onwards. It should integrate awareness and risk-benefit considerations.
Key responsibilities:
- Complete a PhD thesis within the official appointment duration of four year
- Investigate novel nano-embedded carriers of medicines and publish about dose-effect relationships and mechanisms of uptake, biodistribution and effects.
- Collaborate with a variety of stakeholders, so that together standardized workflows and understanding can be established.
- Discuss your work in our group meetings, incorporate feedback, and give input to others
- Assist in writing the deliverables of the tiered approach for the determination of nanomedicine environmental impact based on your scientific achievements.
Your experience and profile:
- Completed or soon-to-be completed MSc in the environmental or biological sciences. or related fields in the natural sciences (e.g., computational, mathematics, earth sciences, physics) with an interest in ecology and evolution
- Demonstrated experience with mathematical modelling, and an ability to learn new concepts and (computational) methods as needed
- Affinity with scientific computer programming (e.g., R) and experimental work
- Proficient communication skills in spoken and written English
Application
Apply here: https://www.universiteitleiden.nl/en/vacancies/2025/q4/16055-phd-candidate-in-ecotoxicology. Please ensure that you upload the following additional documents, quoting the vacancy number:
- Curriculum Vitae
- Cover letter (max 2 pages.)
Deadline: Sunday, 16th of November 2025
Enquiries about the PhD position can be made to Martina Vijver (vijver@cml.leidenuniv.nl).