Probing Lung Function at High Spatiotemporal Resolution Using a Novel Crystal Ribcage

: Real-time, cellular resolution imaging is essential for probing the highly dynamic functions of the lung at the interface of physics, biology, and immunology. CT and MRI modalities have low spatial resolution, and histological approaches provide only snapshots of fixed lungs with little temporal information. Existing intravital imaging approaches cannot include and manipulate the physical and spatiotemporal changes involved in respiratory function. Here, we describe the development of a platform, termed “Lung E x”, to visualize and mechanistically probe the dynamics of a functioning lung at optical resolutions. Lung E x is equipped with a novel transparent ribcage, termed “crystal” ribcage, that provides physiological conditions for a functioning lung and allows high-resolution and real-time optical imaging of nearly the entire lung surface. This imaging capability is obtained while Lung E x preserves the complex 3-D architecture, cellular diversity, and integrative function of the ex vivo ventilated and perfused lung at near in vivo conditions. Utilizing Lung E x in health and key lung diseases such as metastasis, pneumonia, and fibrosis, we probed a wide range of lung dynamic functions and remodeling at multiple spatial scales including alveolar deformation and elasticity, circulation-respiration coupling at the capillary level, cellular deformation, immune cell motility, and vascular transport. By modulating the biophysical environment of Lung E x, we discovered that intravascular