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We designed, synthesized, and characterized a Raman nanoprobe made of dye-sensitized single-walled carbon nanotubes (SWCNTs) that can selectively target biomarkers of breast cancer cells. The nanoprobe is composed of Raman-active dyes encapsulated inside a SWCNT, whose surface is covalently grafted with poly(ethylene glycol) (PEG) at a density of ∼0.7% per carbon. Using α-sexithiopheneand β-carotene-derived nanoprobes covalently bound to an antibody, either anti-E-cadherin (E-cad) or anti-keratin-19 (KRT19), we prepared two distinct nanoprobes that specifically recognize biomarkers on breast cancer cells. Immunogold experiments and transmission electron microscopy (TEM) images are first used to guide the synthesis protocol for higher PEG−antibody attachment and biomolecule loading capacity. The duplex of nanoprobes was then applied to target E-cad and KRT19 biomarkers in T47D and MDA-MB-231 breast cancer cell lines. Hyperspectral imaging of specific Raman bands allows for simultaneous detection of this nanoprobe duplex on target cells without the need for additional filters or subsequent incubation steps. Our results confirm the high reproducibility of the nanoprobe design for duplex detection and highlight the potential of Raman imaging for advanced biomedical applications in oncology.

-/low and ALDH1 expression represents a subpopulation of BCSC (breast cancer stem cell). Several three-dimensional (3D) in vitro culturing cancer cells have been used to stimulate BCSC phenotype. The present study aimed to evaluate 3D cell culture in alginate matrix and the CD44, CD24 and ALDH1 mRNA levels of BCSC markers. The 3D culture was performed using MDA-MB-231 breast cancer cell line on alginate matrix 1.2% in RPMI medium. Expression of BCSC markers was evaluated by Real Time PCR (Polymerase Chain Reaction) comparing 3D to 2D culture. The 3D cultures increase of CD44 and CD24 mRNA levels and induce ALDH1 expression comparing to 2D culture. The data suggest that 3D alginate matrix alters the mRNA levels of genes involved in the phenotypic characteristics of BCSC.Key word: 3D alginate culture, CD44, CD24, ALDH1, breast cancer.

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