title: Luminescent rhenium and ruthenium complexes of an amphoteric poly(amidoamine) functionalized with 1,10-phenanthroline.
abstract: A new amphoteric copolymer, PhenISA, has been obtained by copolymerization of 4-(4'-aminobutyl)-1,10-phenanthroline (BAP) with 2-methylpiperazine and bis(acrylamido)acetic acid (BAC) (6% of phenanthroline-containing repeating units). The copolymer showed excellent solubility in water, where it self-aggregated to give clear nanoparticle suspensions (hydrodynamic diameter = 21 ± 2 nm, by dynamic light scattering (DLS) analysis). The phenanthroline pendants of the polymer stably coordinated either Re(CO)(3)(+) or Ru(phen)(2)(2+) fragments, affording luminescent Re-PhenISA, Re-Py-PhenISA, and Ru-PhenISA polymer complexes, emitting from triplet metal-to-ligand charge transfer ((3)MLCT) excited states (with λ(em) = 608, 571, and 614 nm, respectively, and photoluminescence quantum yields Φ(em) = 0.7%, 4.8%, and 4.1%, in aerated water solution, respectively). DLS analyses indicated that the polymer complexes maintained the nanosize of PhenISA. All the complexes were stable under physiological conditions (pH 7.4, 0.15 M NaCl) in the presence of an excess of the ubiquitous competitor cysteine. In vitro viability assays showed no toxicity of Re-Py-PhenISA and Ru-PhenISA complexes, at concentrations in the range of 0.5-50 μM (calculated on the metal-containing unit), toward HEK-293 (human embryonic kidney) cells. A preliminary investigation of internalization in HEK-293 cells, by means of fluorescence confocal microscopy, showed that Ru-PhenISA enters cells via an endocytic pathway and, subsequently, homogeneously diffuse within the cytoplasm across the vesicle membranes.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy. daniela.maggioni@unimi.it
authors.forename: Daniela
authors.initials: D
authors.lastname: Maggioni
authors.forename: Fabio
authors.initials: F
authors.lastname: Fenili
authors.forename: Laura
authors.initials: L
authors.lastname: D'Alfonso
authors.forename: Daniela
authors.initials: D
authors.lastname: Donghi
authors.forename: Monica
authors.initials: M
authors.lastname: Panigati
authors.forename: Ivan
authors.initials: I
authors.lastname: Zanoni
authors.forename: Roberta
authors.initials: R
authors.lastname: Marzi
authors.forename: Amedea
authors.initials: A
authors.lastname: Manfredi
authors.forename: Paolo
authors.initials: P
authors.lastname: Ferruti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Alfonso
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ranucci
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018613:Microscopy, Confocal; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010618:Phenanthrolines / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D049408:Luminescent Agents; D009942:Organometallic Compounds; D010618:Phenanthrolines; C531249:Poly(amidoamine); D011073:Polyamines; D012211:Rhenium; D012428:Ruthenium; C025205:1,10-phenanthroline