Bioengineers at Queen Mary University of London have made a major advance in creating lab-based models that closely mimic the complexity of living human organs - offering a promising alternative to animal testing.

The team develops organ-on-a-chip technology, where human cells are cultured inside tiny plastic devices designed to replicate the structure and function of real tissues. In their latest study, published in the Journal of Tissue Engineering, researchers unveiled innovative methods that significantly enhance the realism of these models, bringing them even closer to mimicking actual human tissue.

At the heart of this breakthrough is a new way to guide how cells grow and behave by controlling the precise spatial distribution of growth factors - molecules that direct cell activity. Using this approach, the team successfully recreated multiple types of tissue within a single model, including the interfaces where different tissues meet - critical zones for understanding both health and disease.

“The tissues in our bodies are incredibly complex, and recreating this complexity in the lab has always been a challenge,” said Dr Tim Hopkins, lead researcher on the study. “Organ-on-a-chip technology offers a better way to model human tissue, but until now we lacked the tools to capture the full intricacy of real biological systems. Our technique - using growth factor gradients - lets us more accurately mimic the environment cells experience in the body, helping them behave just as they would in real tissue.”

What makes this advance particularly impactful is its versatility. The method can be applied to a wide variety of tissues and commercial organ-on-a-chip platforms, opening the door to broader use in biomedical research. It could dramatically improve how scientists study disease mechanisms and evaluate new therapies - while also reducing reliance on animal testing, which often fails to accurately predict human responses.

“This work could transform how we study disease and test drugs,” said Professor Martin Knight, Co-Director of Queen Mary’s Centre for Predictive in vitro Models. “It has the potential to accelerate the development of safer, more effective treatments and reduce our dependence on animal models.”

To demonstrate their method, the researchers used a growth factor known as bone morphogenetic protein-2 (BMP-2)—key to bone formation. By engineering gradients of BMP-2 within the chips, they guided human stem cells to form bone-like tissue adjacent to cartilage-like tissue, mimicking natural bone development.

The research was supported by grants from the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), the Biotechnology and Biological Sciences Research Council (BBSRC), and the Engineering and Physical Sciences Research Council (EPSRC). The team continues to work closely with industry partners to expand organ-on-a-chip technology, developing models for a wide range of human organs and diseases.