Real-time in vivo imaging of rodent brain response to hypoperfusion enabled by remotely controlled elastomeric micro-balloons

Current preclinical models of ischemic stroke in mice do not permit simultaneous and continuous in vivo brain imaging during the peri-stroke period, therefore missing critical pathophysiological events that could be pivotal for stroke management at the early stage. Here we report remote control of the blood flow of cerebral arteries in live mice continuously at different states to induce stroke in a precise, reliable, and reversible manner. The sub-millimeter scale micro-balloons can expand more than four times their initial diameter, featuring a monolithic elastomeric wall with selectively stiffened regions for controlled inflation and elasticity depending on the target vessels. By allowing for the control of common carotid artery diameter through a cuff pressing against the artery, the micro-balloon recapitulates clinically relevant haemodynamics in a mouse model of global brain ischemia, evidenced by real-time imaging of the brain through intravital microscopy and magnetic resonance imaging. The presented micro-balloons hold significant potential to improve the treatment of stroke patients for minimally invasive intervention and in vivo imaging of the pathophysiological events in the peri-stroke phase.