BACKGROUND: Suitable fluorophores are the core of fluorescence imaging. Among the most exciting, yet controversial, labels are quantum dots (QDs) with their unique optical and chemical properties, but also considerable toxicity. This hinders QDs applicability in living systems. Surface chemistry has a profound impact on biological behavior of QDs. This study describes a two-step synthesis of QDs formed by CdTe core doped with Schiff base ligand for lanthanides [Ln (Yb3+, Tb3+ and Gd3+)] as novel cytocompatible fluorophores. RESULTS: Microwave-assisted synthesis resulted in water-soluble nanocrystals with high colloidal and fluorescence stability with quantum yields of 40.9-58.0%. Despite induction of endocytosis and cytoplasm accumulation of Yb- and TbQDs, surface doping resulted in significant enhancement in cytocompatibility when compared to the un-doped CdTe QDs. Furthermore, only negligible antimigratory properties without triggering formation of reactive oxygen species were found, particularly for TbQDs. Ln-doped QDs did not cause observable hemolysis, adsorbed only a low degree of plasma proteins onto their surface and did not possess significant genotoxicity. To validate the applicability of Ln-doped QDs for in vitro visualization of receptor status of living cells, we performed a site-directed conjugation of antibodies towards immuno-labeling of clinically relevant target-human norepinephrine transporter (hNET), over-expressed in neuroendocrine tumors like neuroblastoma. Immuno-performance of modified TbQDs was successfully tested in distinct types of cells varying in hNET expression and also in neuroblastoma cells with hNET expression up-regulated by vorinostat. CONCLUSION: For the first time we show that Ln-doping of CdTe QDs can significantly alleviate their cytotoxic effects. The obtained results imply great potential of Ln-doped QDs as cytocompatible and stable fluorophores for various bio-labeling applications.

• Klíčová slova
• Cellular labeling, Cytotoxicity, Inorganic fluorophore, Nanocrystal, Surface dopant,
• MeSH
• analýza jednotlivých buněk metody   MeSH
• fluorescenční barviva toxicita   MeSH
• kvantové tečky toxicita   MeSH
• lanthanoidy chemie   MeSH
• lidé MeSH
• mikrovlny MeSH
• nádorové buněčné linie MeSH
• optické zobrazování metody   MeSH
• povrchové vlastnosti MeSH
• Schiffovy báze chemie   MeSH
• sloučeniny kadmia toxicita   MeSH
• telur toxicita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cadmium telluride MeSH Prohlížeč
• fluorescenční barviva MeSH
• lanthanoidy MeSH
• Schiffovy báze MeSH
• sloučeniny kadmia MeSH
• telur MeSH

1-(1H-Benzimidazol-2-yl)-N-(1H-benzimidazol-2-ylmethyl)methanamine (abb) and 2-(1H-benzimidazol-2-ylmethylsulfanylmethyl)-1H-benzimidazole (tbb) have been prepared and characterized by elemental analysis. These bis(benzimidazoles) have been further used in combination with trithiocyanuric acid for the preparation of complexes. The crystal and molecular structures of two of them have been solved. Each nickel atom in the structure of trinuclear complex [Ni3(abb)3(H2O)3(μ-ttc)](ClO4)3·3H2O·EtOH (1), where ttcH3 = trithiocyanuric acid, is coordinated with three N atoms of abb, the N,S donor set of ttc anion and an oxygen of a water molecule. The crystal of [(tbbH2)(ttcH2)2(ttcH3)(H2O)] (2) is composed of a protonated bis(benzimidazole), two ttcH2 anions, ttcH3 and water. The structure is stabilized by a network of hydrogen bonds. These compounds were primarily synthesized for their potential antimicrobial activity and hence their possible use in the treatment of infections caused by bacteria or yeasts (fungi). The antimicrobial and antifungal activity of the prepared compounds have been evaluated on a wide spectrum of bacterial and yeast strains and clinical specimens isolated from patients with infectious wounds and the best antimicrobial properties were observed in strains after the use of ligand abb and complex 1, when at least 80% growth inhibition was achieved.

• Klíčová slova
• benzimidazole, biological activity, coordination compounds, single crystal X-ray diffraction, trimercaptotriazine, trithiocyanuric acid,
• MeSH
• antiinfekční látky chemie   farmakologie   MeSH
• benzimidazoly chemie   farmakologie   MeSH
• inhibiční koncentrace 50 MeSH
• mikrobiální testy citlivosti MeSH
• molekulární modely MeSH
• molekulární struktura * MeSH
• triaziny chemie   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antiinfekční látky MeSH
• benzimidazoly MeSH
• bis-benzimidazole MeSH Prohlížeč
• triaziny MeSH
• trithiocyanuric acid MeSH Prohlížeč