RESUMO
This paper describes on the interaction studies of carbonyl heterobimetallic compounds of Ru(II)/Fe(II) containing polypyridyl ligands, with general formula ct-[RuCl(CO)(N-N)(dppf)]PF6, N-Nâ¯=â¯1,10-phenanthroline (phen) 5; dipyrido[3,2-f:2',3'-h]quinoxaline (dpq) 6; dipyrido[3,2-a:2',3'-c]phenazine (dppz) 7; dipyrido[3,2-f:2',3'-h]quinoxalino[2,3-b]quinoxaline (dpqQX) 8 and dppfâ¯=â¯1,1'-bis(diphenylphosphino) ferrocene], with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA). Also, it describes the cellular viability assays of these complexes in tumorigenic and non-tumorigenic cell lines. The carbonyl complexes 5-8 and their respective precursors with formula cis-[RuCl2(N-N)(dppf)], N-Nâ¯=â¯phen (1), dpq (2), dppz (3) and dpqQX (4), were characterized by elemental analysis and spectroscopic techniques (FTIR, UV-vis, 1H and 31P{1H} NMR). Also, a cyclic voltammetry study was performed for all complexes. The crystal structure of the complex 3 is presented and discussed. Spectrofluorimetric titrations shows spontaneous and strong interaction of 5-8 with BSA, through a static quenching mechanism, resulting in binding constants in the order of 104-106â¯Lâ¯mol-1, at 310â¯K. Viscosity measurements and circular dichroism spectra prompts interactions of 5-8 with ct-DNA via non-classical intercalations or by an electrostatic pathway. MTT assays in breast tumor cells MDA-MB-231 and in non-tumorigenic cells MCF-10A and V79-4â¯cell lines revealed IC50 values ranging from 0.19 to 1.11⯵molâ¯L-1, 1.07-3.18⯵molâ¯L-1 and 1.29-3.85⯵molâ¯L-1 respectively, for complexes 5-8.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Ferro/química , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Piridinas/química , Rutênio/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética , Cricetinae , DNA/metabolismo , Humanos , Ligantes , Células MCF-7 , Modelos Moleculares , Conformação Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/metabolismo , Soroalbumina Bovina/metabolismoRESUMO
We describe herein a novel type of monodisperse water-soluble magnetite nanoparticle coated with pheomelanin using an environmentally-friendly approach in aqueous medium. The results indicate superparamagnetic behaviour at room temperature and show improved negative contrast in T2-weighted MRI with a transverse relaxivity of 218 mM(-1) s(-1).
