Quantifying the effects of nintedanib treatment on bleomycin-induced pulmonary fibrosis mice model in vivo using a novel synchrotron-based imaging method

<bold>Background:</bold> Using our recently developed synchrotron-based x-ray diffraction enhance imaging (DEI)-based multiple-image radiography (MIR) imaging method, we investigated the anti-fibrotic effects of nintedanib (NDN) in bleomycin (BLM)-induced fibrosis in C57BL/6 mice <italic>in vivo</italic>. The animals were exposed to two treatment protocols: continuous (treatment starting before bleomycin challenge) and therapeutic (starting from day 9 after bleomycin challenge, when fibrosis is established) and studied over a 4 weeks period. <bold>Methods:</bold> Intratracheal administration of BLM (2.0 unit/kg) was used to trigger pulmonary fibrosis. Daily NDN treatment (30 mg/kg) via oral gavage was administered for both continuous (n=6) and therapeutic (n=7) treatments. The effect of NDN was compared to untreated control groups: BLM (n=16) and phosphate-buffered saline (PBS, n=6) groups. <bold>Results:</bold> The continuous NDN usage fully prevented the establishment of fibrosis. Similarly, therapeutic NDN treated mice had a reduction in lung parenchyma damage caused by the BLM challenge and lead to faster resolution of fibrosis (Fig 1). <bold>Summary:</bold> Synchrotron-based DEI-MIR provides a novel tool to quantitatively assess the treatment of idiopathic pulmonary fibrosis (IPF) in an animal model of IPF <italic>in vivo</italic>, which could be used to evaluate future therapies in IPF. <fig><object-id>erj;64/suppl_68/PA857/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>