Environmental and human risk assessment of polymer nanocarriers: a review on current analytical challenges and promising approaches

Polymer nanocarriers (PNCs) are designed to deliver active ingredients in pharmaceuticals, food science and agricultural applications and it is essential to ensure their safety towards environmental and human health. Most research and guidance documents on the fate and effect of nanoparticles primarily focus on metal and metal oxide nanomaterials, while nanosafety research on organic nanomaterials is still in the early stages. This review aims to address a set of critical questions that currently prevent the risk assessment of PNCs. Our focus is on the analytical challenges associated with the detection, quantification and characterisation of PNCs in environmental and biological matrices. By addressing the key questions related to the durability, degradability and biological barrier-crossing properties of PNCs, we critically assess the analytical techniques used across different sectors. Our goal is to highlight the strengths and limitations of these analytical methods for the risk assessment of PNCs and to emphasize the significant overlap in the applications of PNCs across various sectors. We also discuss the urgent need for further research to scientifically advance analytical strategies for PNCs, which are essential for supporting responsible innovation in nanotechnology, ensuring the safety of both human and environmental health.