Fingerprint Raman spectroscopy for identification of hydration-dependent Brillouin shift variations in brain tumor tissue

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

The Brillouin shift is a measure of the longitudinal elastic modulus, which is both sensitive to changes in water content and elasticity of the solid part of cells and tissues. Raman spectroscopy can be combined with Brillouin spectroscopy to provide biochemical information. In this study, the Raman signal intensity in the fingerprint region was evaluated to extract additional information about tissue hydration and relate it to the Brillouin shift. Simultaneous and colocalized confocal Brillouin and Raman spectroscopy was performed with laser excitation at 780 nm. Solutions of relevant biomolecules (albumin and sucrose) and gels (gelatin and agarose) with different concentrations up to 30 % as well as glioblastoma organoids and human brain tissue were probed, and the Raman intensity in the spectral region 800 – 1500 cm⁻¹ and Brillouin shift was investigated. A strong linear correlation was found between Raman signal intensity, mass concentration and Brillouin shift for all analyzed solutions and gels, while different mixtures with the same total concentrations had similar Raman intensities. Different degrees of correlation were found between Brillouin shift and Raman intensity on GBM organoids, human brain tissue (epileptic hippocampus) and brain tumor (meningioma), indicating different contributions of tissue hydration and biomechanics to the Brillouin shift. In conclusion, combining fingerprint Raman spectroscopy with Brillouin microscopy is not only useful for extracting biochemical information that highlights changes in Brillouin parameters, but may also provide insight into the effects of local hydration driving the changes of Brillouin shift.

Details

Original languageEnglish
Article number103866
Number of pages9
JournalVibrational Spectroscopy
Volume141
Publication statusPublished - Nov 2025
Peer-reviewedYes

External IDs

ORCID /0000-0001-5084-1180/work/197964616
ORCID /0000-0002-0633-0321/work/197964709
ORCID /0000-0001-5283-0290/work/197964861

Keywords

ASJC Scopus subject areas

Keywords

  • Brain tumors, Brillouin shift, Glioblastoma, Hydrogels, In vitro models, Raman intensity, Water content