A new lab-grown lung model | Replacing Animal Research

The Problem 

We are constantly exposed to airborne particles from sources like vehicle exhaust and dusty workplaces. Most particles are harmless, and we can easily clear them from our lungs, but repeated exposure to toxic particles like coal dust or asbestos can cause chronic lung disease.

Rapid growth in nanotechnology has introduced large numbers of nanomaterials —particles far smaller than the width of a single strand of human hair—into products and workplaces. As their use increases, so does human exposure, especially during manufacturing, causing concern about how these new, tiny particles might affect the lungs.

For current safety testing, regulators currently rely on internationally agreed animal tests, which involve exposing groups of rats or mice to the substance in the air for weeks or months and then examining their lungs and other organs. Altogether, testing a single nanomaterial to the level required for regulatory decision making can use around 280 rodents. Although these studies are classed as “mild” in terms of suffering, some animals may experience more serious effects if the substance causes inflammation, scarring, or even tumours over time.

New, alternative, non-animal methods to assess the potential health effects of NMs are urgently needed.

The Project

Fiona’s team created a prototype model by bioprinting a polymer honeycomb scaffold They then added an ultrathin electrospun membrane, a microscopic mesh of fine fibres, which provides a delicate surface for human cells to grow on, mimicking the natural environment of the body.

The first version used an animal-derived gelatine membrane that successfully supported endothelial cells and fibroblasts. This project aims to develop a fully animal‑product‑free model by replacing the gelatine membrane with alginate, a natural substance extracted from the cell walls of certain types of seaweed.

To achieve this, the electrospinning process needs to be optimised, and methods to improve cell attachment to alginate will be explored. These optimisation steps form the main objectives of the proposal and are essential for developing a new, advanced alternative for testing the toxicity of inhaled nanomaterials.

In a real human lung, oxygen has to pass through a wall that is thinner than a strand of silk to get from the air into your blood. To mimic this, Fiona’s team has built a “cell-sandwich” using a flexible membrane:

Alveolar epithelial cells: These are the cells that line the inside of your lung’s air sacs.
Endothelial cells: These are the cells that line the tiny blood vessels wrapped around your lungs.

By growing these two different types of cells on opposite sides of a thin, stretchy membrane, the team has created a “living” barrier.

Instead of testing chemicals on a flat plastic dish—which doesn’t behave like a human body, this model allows the “air-side” cells and “blood-side” cells to talk to each other.

This offers a far more accurate picture of how inhaled particles might pass from the inside of the lung into the bloodstream.

The system will be tested with a number of known nanomaterials to demonstrate the potential for the model to successfully predict their toxicity. Fiona’s team will also design standardised instructions for model construction and its correct use, which she hopes will also promote the wider adoption of the model by others.

The Potential

Making new technologies easily accessible to other researchers builds confidence across the scientific community in New Approach Methodologies as appropriate alternatives to animal testing.

The team will work directly with relevant professional groups, such as the British Toxicology Society and the UK NanoSafety Group, where Fiona is already an active member, to share progress, gather feedback, and explore how this model could be built into existing decision‑making processes for assessing inhalation hazards.