Development of a prototype of an aerosolization device for dry powders to improve in vitro cell-based assays in the context of lung delivery

Jorge F. Pontes^1,2, Hermínio P. Diogo³, Eusébio Conceição⁴, Flávia Musacchio¹,

Rui M. Borges dos Santos^1,4 & Ana Grenha^1,4

 ¹Centre for Marine Sciences, Universidade do Algarve, Campus de Gambelas, Faro, 8005-139, Portugal

²Centre for Biomedical Research, Universidade do Algarve, Campus de Gambelas, Faro, 8005-139, Portugal

³University of Lisbon, Instituto Superior Técnico, Centro de Química Estrutural, Av. Rovisco Pais, 1049-001 Lisbon, Portugal

⁴Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus Gambelas, Faro, 8005-139, Portugal

Summary

The lung has been, for the past years, subject of intense research for local and systemic drug delivery approaches.  However, robust correlations between in vitro and in vivo results are often impaired, as in vitro experiments frequently have limitations mimicking lung conditions, especially when involving cell-based studies. This work proposes a 3D-printed device for aerosolization of dry powders over cells in culture, thus better resembling the conditions of aerosolization occurring in vivo. The proposed device comprises two parts, the weighing head, and the main body. Dry powders are weighed in the weighing head, which is then sealed to the main body.  Next, compressed air is injected into the device, dragging the powder onto a plate, which fits the bottom of the main body.
The plate is a suitable surface for cell culture. Dry powders (polysaccharide-based microparticles) were tested using the device, leading to an aerosolization yield up to 51%, which was observed to depend on the tested dry powder.  The dry powder deposition profile is currently being evaluated using a Quartz-Crystal Microbalance, which replaces the plate at the bottom of the device’s main body. These experiments entail a more precise determination of the mass of aerosolized powders by analysing the differences in the vibration frequencies of a quartz crystal, thus allowing to assess the deposition profile. Although preliminary, the results show that the developed device may comprise an affordable solution for in vitro testing of dry powders when aerosolization over a surface is required.