Photoswitchable Nanoparticles for High-Contrast Photoacoustic Microscopy to Image Inflammation in Microvasculature – AZOTICS

The recent rise of high-resolution and depth imaging techniques like photoacoustic microscopy (PA) stimulates novel research areas in biology. In vivo tracking of immune cells, signaling inflammation and severe pathologies thereof, is one of them and attracts great interest. The AZOTICS project thus aims at addressing the current PA microscopy limitations by fabricating innovative biocompatible elastomeric nanolabels relying on azo photochromes. Photostimulated actuation mechanisms will help amplify the PA contrast based on thermal expansion. The photoinduced mechanical deformations of single nano-objects will be assessed at the nanoscale using atomic force microscopy in order to propose a rationale for the performance of photoacoustic probes beyond their sole optical absorption ability. Their PA imaging capability will be validated through an in vitro, in cellulo and in vivo continuum of studies involving macrophage staining, microfluidic systems mimicking microvasculature, and models of acute inflammatory activated in mice. The interdisciplinary AZOTICS consortium gathers experts in chemistry, physics and optics from Nantes and Grenoble, having already tightly worked together and being keen to share their knowledge in order not only to address unexplored fundamental questions but also to propose innovative photoacoustic systems for in vivo imaging.