In the labs of CIC biomaGUNE in Bilbao, researchers have engineered particles so small they mimic the very substance that lines your lungs and lets you breathe. These pulmonary surfactant nanoparticles—built from the same lipids and proteins your body naturally produces—carry antifibrotic drugs directly to diseased lung tissue, offering a gentler path forward for the millions living with pulmonary fibrosis.
Pulmonary fibrosis is a relentless disease: lung tissue scars progressively, becoming thickened and stiff, making each breath harder than the last. Smoking, occupational exposure to dust and chemicals, chemotherapy, radiotherapy, and even viral diseases like COVID-19 can trigger it. Yet conventional treatments, administered orally, come with significant side effects that can be almost as difficult as the disease itself. This is why Dr. Susana Carregal and her team at the Molecular and Functional Biomarkers group took a different approach—one inspired by the lung's own defenses.
"The lung is filled with pulmonary surfactant; this is the interface where the exchange between air and fluid takes place," Dr. Carregal explained. The insight was elegant: instead of fighting the lung's natural barriers, why not work with them? By encapsulating the antifibrotic drug in nanoparticles made from pulmonary surfactant itself, the researchers created a delivery system the lungs would recognize as a friend rather than a foreign invader. When administered by inhalation, these particles distribute more evenly throughout the lung tissue and lodge where they're needed most.
The results are striking. In mouse models, 90% of the administered nanomedicine remained trapped in the lungs—far higher retention than conventional treatments allow. This means less drug reaches the liver and other organs, dramatically reducing the side effects that make current pulmonary fibrosis treatment so challenging. The researchers also simplified and automated the synthesis method using microfluidics, a technique that manages fluids at microscopic scale with extraordinary precision. This produces nanomedicines with tightly controlled size, direct encapsulation of the drug, and remarkable consistency—making the treatment both reproducible and ready for standardization.
The study, published in Advanced Healthcare Materials, represents more than just incremental progress. Dr. Carregal notes that the new synthesis method "opens up new avenues for developing inhaled treatments for lung diseases." The achievement lies not in inventing something entirely foreign to the body, but in learning to speak the lung's own language. By preserving the native proteins and lipids of pulmonary surfactant and its biophysical functionality, the team created a biomimetic platform—one that works with the body's own biology rather than against it.
For patients with pulmonary fibrosis, this could mean lower doses, fewer side effects, and a treatment that targets diseased tissue directly rather than circulating systemically. For the field of respiratory medicine more broadly, it signals a shift toward smarter drug delivery: understanding that sometimes the best way forward is to mimic what evolution has already perfected. The research demonstrates that innovation in medicine often comes not from fighting nature, but from listening to it.