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Updated: Nov 7, 2025
An Integrated Raman Spectroscopy and Mass Spectrometry Platform to Study Single-Cell Drug Uptake, Metabolism, and Effects
Published on: January 9, 2020
Investigation of squalene-doxorubicin distribution and interactions within single cancer cell using Raman
Hassan Rammal1, Almar Al Assaad1, Franco Dosio2
1Translational BioSpectrocopy, BioSpecT, EA 7506, Université de Reims, Faculté de Pharmacie, Reims, France.
Abstract:
Intracellular distribution of doxorubicin (DOX) and its squalenoylated (SQ-DOX) nanoparticles (NPs) form in murine lung carcinoma M109 and human breast carcinoma MDA-MB-231 cells was investigated by Raman microspectroscopy. Pharmacological data showed that DOX induced higher cytotoxic effect than SQ-DOX NPs. Raman data were obtained using single-point measurements and imaging on the whole cell areas. These data showed that after DOX treatment at 1 μM, the spectral features of DOX were not detected in the M109 cell cytoplasm and nucleus. However, the intracellular distribution of SQ-DOX NPs was higher than DOX in the same conditions. In addition, SQ-DOX NPs were localized into both cell cytoplasm and nucleus. After 5 μM treatment, Raman bands of DOX at 1211 and 1241 cm-1 were detected in the nucleus. Moreover, the intensity ratio of these bands decreased, indicating DOX intercalation into DNA. However, after treatment with SQ-DOX NPs, the intensity of these Raman bands increased. Interestingly, with SQ-DOX NPs, the intensity of 1210/1241 cm-1 ratio was higher suggesting a lower fraction of intercalated DOX in DNA and higher amount of non-hydrolyzed SQ-DOX. Raman imaging data confirm this subcellular localization of these drugs in both M109 and MDA-MB-231 cells. These finding brings new insights to the cellular characterization of anticancer drugs at the molecular level, particularly in the field of nanomedicine.
Insights
Squalenoylated doxorubicin nanoparticles show enhanced intracellular distribution and nuclear localization compared to free doxorubicin in cancer cells, offering new insights into nanomedicine delivery.
Area of Science:
- Nanomedicine
- Molecular Spectroscopy
- Cancer Biology
Background:
- Doxorubicin (DOX) is a potent chemotherapy drug with limitations in targeted delivery.
- Squalenoylated doxorubicin (SQ-DOX) nanoparticles (NPs) were developed to improve DOX delivery.
- Understanding intracellular drug distribution is crucial for optimizing cancer therapy.
Purpose of the Study:
- To investigate the intracellular distribution of DOX and SQ-DOX NPs in cancer cells.
- To compare the cellular uptake and localization of free DOX versus SQ-DOX NPs.
- To elucidate the molecular interactions of SQ-DOX NPs with cellular components, particularly DNA.
Main Methods:
- Raman microspectroscopy was employed for single-point measurements and imaging.
- Murine lung carcinoma M109 and human breast carcinoma MDA-MB-231 cells were used.
- Cells were treated with varying concentrations of DOX and SQ-DOX NPs.
Main Results:
- SQ-DOX NPs exhibited higher intracellular distribution and nuclear localization than free DOX.
- Free DOX was not detected in M109 cell cytoplasm and nucleus at 1 μM.
- Raman data suggested reduced DOX intercalation into DNA with SQ-DOX NPs compared to free DOX.
Conclusions:
- SQ-DOX NPs demonstrate superior cellular uptake and nuclear delivery compared to free DOX.
- Raman microspectroscopy provides molecular-level insights into nanomedicine-drug interactions.
- These findings advance the understanding of anticancer drug behavior at the cellular level for nanomedicine applications.
