title: Live-cell-permeant thiophene fluorophores and cell-mediated formation of fluorescent fibrils.
abstract: In our search for thiophene fluorophores that can  overcome the limits of currently available organic dyes in live-cell staining, we synthesized biocompatible dithienothiophene-S,S-dioxide derivatives (DTTOs) that were spontaneously taken up by live mouse embryonic fibroblasts and HeLa cells. Upon treatment with DTTOs, the cells secreted nanostructured fluorescent fibrils, while cell viability remained unaltered. Comparison with the behavior of other cell-permeant, newly synthesized thiophene fluorophores showed that the formation of fluorescent fibrils was peculiar to DTTO dyes. Laser scanning confocal microscopy of the fluorescent fibrils showed that most of them were characterized by helical supramolecular organization. Electrophoretic analysis and theoretical calculations suggested that the DTTOs were selectively recognized by the HyPro component of procollagen polypeptide chains and incorporated through the formation of multiple H-bondings.
authors.affiliation: NNL-CNR Nanoscience Institute, Università del Salento, Via Arnesano, 73100 Lecce, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Palamà
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Maria
authors.forename: Ilenia
authors.initials: I
authors.lastname: Viola
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fabiano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gigli
authors.forename: Cristian
authors.initials: C
authors.lastname: Bettini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Barbarella
mesh_terms: D000818:Animals; D005347:Fibroblasts / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D013876:Thiophenes