PAMAM dendrimers functionalized with ruthenium nitrosyl as nitric oxide carriers

摘要

The functionalization of three generations of polyamidoamine (PAMAM G0, G2 and G3) dendrimers with the NO-donor trans-[Ru(NO)(NH_3)_4(ina)](BF_4)_3 (ina = isonicotinic acid) is reported. PAMAMs were modified through a peptide-type bond between the carboxyl group of the ina ligand and the dendrimer superficial amines. Compounds were characterized by FT-IR, UV-Vis, CV, DPV, ~1H NMR, ICP-OES, and the structure of the complextrans-[Ru(NO)(NH_3)_4(ina)](BF_4)(SiF_6)?H_2O was determined by single crystal X-Ray analysis. The experimental data indicated the immobilization of 4, ~8 and ~27 nitrosyl complexes on the G0, G2 and G3 dendrimer's surface, respectively, which corresponds to ~1.0-1.43 lmol NO per mg of dendrimer. FT-IR, UV-Vis and electrochemical assays suggest that the functionalization of PAMAM did not alter the coordination sphere of the ruthenium nitrosyl complex neither the formal reduction potential of Ru~(II)NO~+/Ru~(II)NO~0 coupleregarding to the complex not attached to PAMAM. The NO release in these compounds, through light irradiation (k = 355 nm) and one-electron reduction (Eu~(2+)), was