Immortalized human cells to model atrial fibrillation in vitro
Niels Harlaar is a PhD Candidate at the Laboratory of Experimental Cardiology at the Leiden University Medical Center. Here, under the supervison of prof. dr. D.A. Pijnappels and dr. A.A.F. de Vries, he focusses on the conditional immortalization of human atrial cardiomyocytes for (among many other applications) in vitro modelling of atrial fibrillation. He has successfully generated, characterized and applied this technique of these conditionally immortalized human atrial myocyte lines to model atrial fibrillation in vitro.
Niels won the Hugo van Poelgeest prize 2022 for excellent research to replace animal testing.
Click here for more information on the Laboratory of Experimental Cardiology.
New

Projects and initiatives
HealthToxicology
The NAM Navigator: A unique repository for information on the validation and acceptance of New Approach Methodologies
The NAM navigator is an innovative knowledge portal to navigate you to and through valuable information on the development, standardization, validation and acceptance of New Approach Methodologies (NAM). The NAM Navigator acts as an online guide that provides specific information needed in each of these steps, thereby increasing the broad use of animal-free innovations. Follow the link in the video to start navigating!

Projects and initiatives
HealthToxicologyIn vitroIn silico
VHP4Safety project
The safety testing of chemicals and pharmaceuticals traditionally relies on animal studies. However, these raise ethical concerns and often fail to accurately predict human responses. New scientific developments offer opportunities to build a Virtual Human Platform (VHP) for safety assessment, a platform that enables assessment based solely on human physiology and biology, integrating data from in vitro and in silico models. This video explains how we are developing the VHP through an interdisciplinary approach. Read the paper in the videolink or visit or VHP4Safety (https://vhp4safety.nl/) for more information.

Innovation examples
HealthToxicologyIn silico
AI agents for safer science: How AI is Changing Chemical Risk Assessment
This video introduces a novel approach to chemical safety, where intelligent digital agents guided by large language models support scientists in making faster, more transparent decisions. By automating complex workflows and integrating tools like the OECD QSAR Toolbox, these agentic systems help prioritise research, reduce reliance on animal testing, and pave the way for safer, more sustainable innovation.

Innovation examples
ToxicologyPolicy
User Research in developing the virtual human platform
Digital tools can support the phasing out of animal-based tests and data in chemical risk assessment. This is one of the core promises of the Virtual Human Platform. The potential contribution of digitalization is linked to the acceptance and adoption of tools, methods, and data by stakeholders in several societal sectors. To facilitate the integration of stakeholders in the configuration of digital tools, Dr. Isaac Ortega Alvarado and colleagues gather insights from risk assessors in their role as users. Risk assessors are the ones who actualize chemical risk assessment and its standards through their practices. With this perspective, this research contributes to understanding the development and implementation of digital tools as embedded in social processes of construction and reception.