During this award period we have researched and constructed a multi-modal imaging platform allowing for non-destructive analysis of vascular tissues scaffolds/constructs and have begun the validation of this platform in two study models. Our current platform integrates unique optical imaging and spectroscopy technologies with advanced ultrasound techniques. The optical component is designed to provide a rapid assessment of vascular constructs biochemical features with high molecular sensitivity as well as to imaging the construct microstructure with very high resolution. The ultrasound component is designed to image rapidly the construct morphology as well as to measure the construct mechanical properties or local elastic properties that subsequently can be correlated with construct functionality. Moreover, we have developed a 3D printed system for production and cellular repopulation of vessels. Additionally, we have developed two model systems for assessment of cellular interaction with their supporting tissue environment – the extracellular matrix niche. These model systems have been utilized to assess the effect of the extracellular matrix niche on behavior of human stem cells. Importantly, we have demonstrated that different extracellular matrix niches are capable of modulating stem cell growth and function. We have further demonstrated that the bimodal non-invasive imaging platform developed under this proposal has high sensitivity for assessing small differences in extracellular matrix niche. The developed bimodal system therefore has potential for monitoring presence of seeded cells and the effect such cells on turnover of their extracellular matrix environment.