title: Sialic Acid-Imprinted Fluorescent Core-Shell Particles for Selective Labeling of Cell Surface Glycans.
abstract: The expression of cell surface glycans terminating with sialic acid (SA) residues has been found to correlate with various disease states there among cancer. We here report a novel strategy for specific fluorescence labeling of such motifs. This is based on sialic acid-imprinted core-shell nanoparticles equipped with nitrobenzoxadiazole (NBD) fluorescent reporter groups allowing environmentally sensitive fluorescence detection at convenient excitation and emission wavelengths. Imprinting was achieved exploiting a hybrid approach combining reversible boronate ester formation between p-vinylphenylboronic acid and SA, the introduction of cationic amine functionalities, and the use of an NBD-appended urea-monomer as a binary hydrogen-bond donor targeting the SA carboxylic acid and OH functionalities. The monomers were grafted from 200 nm RAFT-modified silica core particles using ethylene glycol dimethacrylate (EGDMA) as cross-linker resulting in a shell thickness of ca. 10 nm. The particles displayed strong affinity for SA in methanol/water mixtures (K = 6.6 × 10(5) M(-1) in 2% water, 5.9 × 10(3) M(-1) in 98% water, B(max) ≈ 10 μmol g(-1)), whereas binding of the competitor glucuronic acid (GA) and other monosaccharides was considerably weaker (K (GA) = 1.8 × 10(3) M(-1) in 98% water). In cell imaging experiments, the particles selectively stained different cell lines in correlation with the SA expression level. This was further verified by enzymatic cleavage of SA and by staining using a FITC labeled SA selective lectin.
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Sudhirkumar
authors.initials: S
authors.lastname: Shinde
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Zahra
authors.initials: Z
authors.lastname: El-Schich
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Atena
authors.initials: A
authors.lastname: Malakpour-Permlid
authors.affiliation: Chemical and Optical Sensing Division, Federal Institute for Materials Research and Testing (BAM) , 12200 Berlin, Germany.
authors.forename: Wei
authors.initials: W
authors.lastname: Wan
authors.affiliation: Department of Translational Medicine, Lund University , SE-20502 Malmö, Sweden.
authors.forename: Nishtman
authors.initials: N
authors.lastname: Dizeyi
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Reza
authors.initials: R
authors.lastname: Mohammadi
authors.affiliation: Chemical and Optical Sensing Division, Federal Institute for Materials Research and Testing (BAM) , 12200 Berlin, Germany.
authors.forename: Knut
authors.initials: K
authors.lastname: Rurack
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Anette
authors.initials: A
authors.lastname: Gjörloff Wingren
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden.
authors.forename: Börje
authors.initials: B
authors.lastname: Sellergren
mesh_terms: D045744:Cell Line, Tumor; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D019158:N-Acetylneuraminic Acid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010069:Oxadiazoles / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D010069:Oxadiazoles; D011134:Polysaccharides; D019158:N-Acetylneuraminic Acid