Multimodal optical coherence microscopy, mechano-microscopy, and fluorescence microscopy for three-dimensional characterization of multicellular spheroids

Multicellular spheroids are a powerful model to study biochemical and biophysical interactions between cancer cells during growth and progression. However, little is known about how the biomechanics of the three-dimensional (3-D) microenvironment control cancer cell behaviors due to the lack of enabling technologies that can measure 3-D subcellular-scale elasticity and co-register it with the morphology and function of cells in a 3-D microenvironment. Here, we propose a multimodal imaging system that integrates an optical coherence microscopy-based subcellular mechano-microscopy system with a multi-channel confocal fluorescence microscopy system. Using this multimodal imaging system, we scan non-metastatic MCF7 breast cancer cell spheroids encapsulated in gelatin methacryloyl (GelMA) hydrogels and co-register 3-D intra-spheroid elasticity with subcellular structures, such as nuclei and cell membranes.