Traditional Posters: Body Imaging

2694. Quantitative MRI Assessment of Matrix Development in Cell-Seeded Natural Urinary Bladder Smooth Muscle Tissue-Engineered Constructs

Hai-Ling Margaret Cheng^1,2, Syed S. Islam³, Yasir Loai³, Roula Antoon³, Marine Beaumont¹, Walid A. Farhat<sup>3

1</sup>Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; ²Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; ³Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada

Cell-seeded natural tissue scaffolds hold promise for tissue-engineering large organs (e.g. the urinary bladder matrix for regenerating different tissue types). However, our understanding of cell-natural matrix interaction is limited, and its influence on MRI characterization is unknown. This study explores quantitative MRI at 1.5 T for investigating cell-matrix interaction and matrix development in a smooth muscle cell-seeded bladder model. Competing with cell presence was matrix degradation due to cell-released collagenase, noted for the first time and perhaps unique to natural matrices. Quantitative T1, T2, and diffusion measurements are consistent with collagen breakdown, with multicomponent T2 providing the best specificity.