A 3-D laboratory method has been developed to test asthma and allergy medications that mimics what happens in the body, according to researchers at the American Chemical Society (ACS). The findings, says ACS, could help reduce the need for animal testing, which can be a costly, laborious and ethically challenging.

The study, which was published in Molecular Pharmaceutics, reports that previously, researchers used 2-D tests that required applying the drug to a layer of human cells in a lab dish. However, according to lead author Amir Ghaemmaghami, using a 2-D model isn’t an adequate way to tell how a medicine will work in a whole animal or a whole person.

“The development of more complex in vitro models for the assessment of novel drugs and chemicals is needed because of the limited biological relevance of animal models to humans as well as ethical considerations,” wrote Ghaemmaghami and his team. “Although some human-cell-based assays exist, they are usually 2-D, consist of single cell type, and have limited cellular and functional representation of the native tissue.”

As a result, Ghaemmaghami and his team used biomimetic porous electrospun scaffolds to develop an immunocompetent 3-D model of the human respiratory tract comprised of three key cell types present in upper airway epithelium. The three cell types, namely, epithelial cells (providing a physical barrier), fibroblasts (extracellular matrix production), and dendritic cells (immune sensing), were initially grown on individual scaffolds and then assembled into the 3-D multicell tissue model.

Their test includes three types of human cells that are typically in a person’s airway. In the body, these cells are close together and are involved in the development of respiratory conditions. The 3-D model reacted just like an actual person’s airway when exposed it to allergens and bacterial extract. As a result, the authors note that the model has the potential to reduce the need for some animal testing of new drugs for respiratory conditions.

“This model provides an easy to assemble and physiologically relevant 3-D model of human airway epithelium that can be used for studies aiming at better understanding lung biology, the cross-talk between immune cells, and airborne allergens and pathogens as well as drug delivery,” the authors concluded.