Label-free 3-D molecular imaging of living tissues using Raman Spectral Projection Tomography

Stepula, E.; Walther, A. R.; Mehrotra, D.; Jensen, M.; Yuan, M. H.; Pedersen, S. V.; Gentleman, E.; Albro, M. B.; Hedegaard, M. A. B.; Bergholt, M. S.

doi:10.1101/2023.09.23.559025

bioRxiv · 10.1101/2023.09.23.559025

Label-free 3-D molecular imaging of living tissues using Raman Spectral Projection Tomography

Stepula, E.·Walther, A. R.·Mehrotra, D.·Jensen, M.·Yuan, M. H.·Pedersen, S. V.·Gentleman, E.·Albro, M. B.·Hedegaard, M. A. B.·Bergholt, M. S.

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Abstract

The ability to image tissues in three-dimensions (3-D) with label-free molecular contrast at mesoscale would be a valuable capability in biology and biomedicine. Here, we introduce Raman spectral projection tomography (RSPT) for volumetric molecular imaging with sub-millimeter spatial resolution. We have developed a RSPT imaging instrument capable of providing 3-D molecular contrast in transparent and semi-transparent samples. A computational pipeline for multivariate reconstruction was established to extract label-free spatial molecular information from Raman projection data. We demonstrate imaging and visualization of phantoms of various complex shapes with label-free molecular contrast. Finally, we apply RSPT as a novel tool for imaging of molecular gradients and extracellular matrix heterogeneities in fixed and live tissue-engineered constructs and explanted native tissues. RSPT imaging opens new possibilities for label-free molecular monitoring of tissues.

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Stepula, E., Walther, A. R., Mehrotra, D., Jensen, M., Yuan, M. H., Pedersen, S. V., Gentleman, E., Albro, M. B., Hedegaard, M. A. B., Bergholt, M. S.. 2023-09-24. Label-free 3-D molecular imaging of living tissues using Raman Spectral Projection Tomography. https://doi.org/10.1101/2023.09.23.559025

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