title: Surface-enhanced Raman scattering reveals adsorption of mitoxantrone on plasma membrane of living cells.
abstract: Surface-enhanced Raman scattering (SERS) spectroscopy was applied to analyze mitoxantrone (MTX) adsorption on the plasma membrane microenvironment of sensitive (HCT-116 S) or BCRP/MXR-type resistant (HCT-116 R) cells. The addition of silver colloid to MTX-treated cells revealed an enhanced Raman scattering of MTX. Addition of extracellular DNA induced a total extinction of MTX Raman intensity for both cell lines, which revealed an adsorption of MTX on plasma membrane. A threefold higher MTX Raman intensity was observed for HCT-116 R, suggesting a tight MTX adsorption in the plasma membrane microenvironment. Fluorescence confocal microscopy confirmed a relative MTX emission around plasma membrane for HCT-116 R. After 30 min at 4 degrees C, a threefold decrease of the MTX Raman scattering was observed for HCT-116 R, contrary to HCT-116 S. Permeation with benzyl alcohol revealed a threefold decrease of membrane MTX adsorption on HCT-116 R, exclusively. This additional MTX adsorption should correspond to the drug bound to an unstable site on the HCT-116 R membrane. This study showed that SERS spectroscopy could be a direct method to reveal drug adsorption to the membrane environment of living cells.
authors.affiliation: Unité MéDIAN CNRS UMR 6142, IFR53, UFR de Pharmacie, 51 rue Cognacq-Jay, 51096 Reims, France.
authors.forename: G
authors.initials: G
authors.lastname: Breuzard
authors.forename: J-F
authors.initials: JF
authors.lastname: Angiboust
authors.forename: P
authors.initials: P
authors.lastname: Jeannesson
authors.forename: M
authors.initials: M
authors.lastname: Manfait
authors.forename: J-M
authors.initials: JM
authors.lastname: Millot
mesh_terms: D000327:Adsorption; D000970:Antineoplastic Agents / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008942:Mitoxantrone / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D000970:Antineoplastic Agents; D008942:Mitoxantrone