Micro-Raman Spectroscopy of Extracellular Vesicles Derived from Stored Blood Components: Towards Label-Free Molecular Characterization
Mithun N1 and Santhosh Chidangil 1,2
1.Centre of Excellence for Biophotonics, Manipal Institute of Applied Physics, Manipal Academy of Higher Education, Manipal, Karnataka, India
2.Department of Physics, JSS Science and Technology University, Mysuru, Karnataka, India
Abstract
Extracellular vesicles (EVs) isolated from stored red blood cells and platelet concentrates were characterized using Micro-Raman spectroscopy. Distinct molecular fingerprints revealed differences in protein and lipid composition, while the absence of hemoglobin signatures in RBC-derived EVs indicated selective molecular packaging. The study highlights Micro-Raman spectroscopy as a rapid, label-free tool for EV characterization.
In the present study, we demonstrate the application of Micro-Raman spectroscopy for the molecular characterization of extracellular vesicles isolated from packed red blood cells (PRBCs) and platelet concentrates (PCs) during storage. EVs were isolated using polyethylene glycol (PEG)-based precipitation and characterized by nanoparticle tracking analysis (NTA), which confirmed mean particle sizes of approximately 120 nm for RBC-derived EVs and 170 nm for platelet-derived EVs. Raman spectra were acquired using a lab assembled micro-Raman system, enabling non-destructive biochemical analysis without the need for labels or molecular probes [1].
Distinct Raman signatures corresponding to proteins, lipids, and membrane-associated biomolecules were observed in both EV populations. Unlike their parent red blood cells, RBC-derived EVs exhibited negligible hemoglobin-specific Raman bands, indicating selective molecular packaging during vesicle formation. Comparative spectral analysis further revealed biochemical differences between RBC- and platelet-derived EVs, reflecting their unique cellular origins and biological functions. These findings demonstrate the capability of Micro-Raman spectroscopy to sensitively probe the molecular composition of nanoscale extracellular vesicles [2].
Conclusion: Micro-Raman spectroscopy provides a rapid, label-free platform for extracellular vesicle characterization. Combined with complementary analytical techniques, it holds significant promise for developing EV-based biomarkers for transfusion medicine and disease diagnosis.
References:
[1] Van Niel G, d'Angelo G, Raposo G. Shedding light on the cell biology of extracellular vesicles. Nature Reviews Molecular Cell Biology. 2018;19(4):213-28
[2] Mithun N, Lukose J, Mohan G, Shastry S, Chidangil S. Single cell spectroscopy of red bloodcells in intravenous crystalloid fluids. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2021;257:119726.
Speaker
Dr. Santhosh Chidanghil
JSS Science and Technologhy University
India
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