Development of Inhaled Platelet-based Therapy to Repair Damaged Lungs  

Ziru Xu, Ben Forbes, Simon Pitchford & Magda Swedrowska

King’s College London, Institute of Pharmaceutical Science, London SE1 9NH, UK

Summary

As the first defence line in the lungs, the epithelium can be damaged by infections, inflammation, toxic compounds, and trauma. It is critical to recover a healthy epithelial barrier after lung injury. Platelets produce many different types of growth factors which promote cell growth and tissue regeneration. The aim of this project was to investigate the regenerative role of platelet extract on lung alveolar epithelial cells and the potential for development into an inhaled medicine. To gain the extract, platelets were subjected to ultrasound sonication to release their cell contents. Cell proliferation assays using A549 cells showed that sonicated platelet extract enhanced alveolar epithelial cell growth in a time- and concentration- dependent manner. The extract also accelerated closure of a scratched wound on the monolayer of A549 cells. When nebulised with an Aerogen Pro^® mesh nebuliser, the extract produced an aerosol with a fine particle fraction below 5 µm of ca. 50% and no loss of activity in bioassay. In conclusion, sonicated platelet extract was effective at promoting alveolar epithelial cell growth and can be nebulised to form a bioactive respirable aerosol.

Key Message

Lung injury is associated with high morbidity and mortality and there are currently limited pharmacological options for treatment. Platelet-derived therapy has proven a regenerative action in non-respiratory disease, and this work describes the production of formulation that will enable proof-of-concept testing for application in lung injury.