Model carrier microparticles for inhaled medicines developed with high-precision 3D laser printing

They are barely thicker than a human hairyet – they could significantly improve the effectiveness of inhaled medications: carrier particles in dry powder inhalers transport the active ingredient and ensure it can be efficiently inhaled into the lungs. How well this works depends strongly on their shape.

A team led by Professor Regina Scherliesss at Kiel University (CAU) has now, for the first time, produced tiny carrier particles with precisely defined geometries and used them to investigate the role of particle shape in the inhalation process – employing a highly precise 3D printing technique.

The researchers discovered that particle shape has a marked impact on the amount of active ingredient that can be inhaled. Of the four designs tested, one variant performed significantly better than the others. The results have been published in Communications Materials.

An innovative 3D printing method made it possible to produce millions of precisely shaped particles in series. Two-photon polymerization is a process that operates with nanometer resolution. A laser selectively activates tiny points in the material, which immediately harden.

For each of the four designs tested, the team produced more than 2 million identical particles. They then combined the particles with a model drug, as in real inhalation formulations.

Image source: Communications Materials, Kiel University.