title: Cube-octameric silsesquioxane-mediated cargo peptide delivery into living cancer cells.
abstract: Cube octameric silsesquioxanes (COSS) are among the smallest nanoparticles known to date with a diameter of only 0.7 nm. We describe a COSS-based delivery system which allows for the drug targeting in human cells. It comprises a siloxane core with seven pendant aminopropyl groups and a fluorescently labeled peptidic ligand attached to one cage corner via a reversible disulfide bond to ensure its intracellular release. Bimodal amplitude-modulated atomic force microscopy (AFM) experiments revealed the formation of dendritic COSS structures by a self-assembly of single particles on negatively charged surfaces. Nuclear targeting was demonstrated in HeLa cells by selective binding of released p21(Cip1/Waf1)-derived cargo peptide to PCNA, a protein involved in DNA replication and repair.
authors.affiliation: Clemens-Schöpf Institute of Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Petersenstr. 22, 64287 Darmstadt, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hörner
authors.forename: Sebastian
authors.initials: S
authors.lastname: Fabritz
authors.forename: Henry D
authors.initials: HD
authors.lastname: Herce
authors.forename: Olga
authors.initials: O
authors.lastname: Avrutina
authors.forename: Christian
authors.initials: C
authors.lastname: Dietz
authors.forename: Robert W
authors.initials: RW
authors.lastname: Stark
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Cardoso
authors.forename: Harald
authors.initials: H
authors.lastname: Kolmar
mesh_terms: D002851:Chromatography, High Pressure Liquid; D016503:Drug Delivery Systems; D006367:HeLa Cells; D006801:Humans; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry; D017646:Organosilicon Compounds / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*
chemical_list: D017646:Organosilicon Compounds; D010455:Peptides; D018809:Proliferating Cell Nuclear Antigen; D000644:Quaternary Ammonium Compounds; C018408:3-(trimethoxysilyl)propyldimethyloctadecylammonium