Development of quantum dot mediated cell image deformetry for microscale tissue deformation measurement

Since biological tissues are composed of cells, extracellular matrix, and interstitial fluid, freezing of biological tissues induces complex cell-fluid-matrix interaction. Quantitative understanding of this cell-fluid-matrix interaction is crucial to the design and optimization of a wide variety of cryomedicine applications. However, quantitative measurement of the interaction is extremely challenging due to the lack of reliable non-invasive measurement techniques during freezing and thawing. In the present study, a new measurement technique was developed to dynamically measure microscale tissue deformation during freezing/thawing and its feasibility was demonstrated. In this method, which is named "Cell Image Deformetry" (CID), engineered tissues with pre-labeled cells with quantum dots are imaged under a fluorescence microscope. Then, the tissue deformation is evaluated by cross-correlating cell locations between sequential microscopic images with known time intervals based on the particle image velocimetry (PIV) data processing technique.