RESUMO
Zinc-tetracarboxy-phthalocyanine (ZnPc(COOH)4) was synthesized by a melting method and basic hydrolysis. A ZnPc(COOH)4/Fe3O4/Ch composite was prepared by immobilization of ZnPc(COOH)4 onto Fe3O4/chitosan nanoparticles by a simple immersion method. The photophysical properties were studied using UV-vis spectrophotometry, fluorescence spectroscopy and time-correlated single photon counting (TCSPC) in different aqueous solutions. The UV-vis spectra of the ZnPc(COOH)4/Fe3O4/Ch composite displays absorption by the aromatic rings, with a Q band exhibited at λ max = 702 nm. Moreover, the ZnPc(COOH)4/Fe3O4/Ch composite exhibits long triplet-state lifetimes of 1.6 µs and 12.3 µs, crucial for application as a photosensitizer. A triplet quantum yield of 0.56 for the ZnPc(COOH)4/Fe3O4/Ch composite in DMSO/H2O was achieved. FTIR showed that the conjugation of ZnPc(COOH)4 with Fe3O4/chitosan nanoparticles was achieved by electrostatic interaction.
RESUMO
This paper focuses on the linking of zinc phthalocyanine (ZnPc) to N-vinylpyrrolidone (N-VP): acryloyl chloride (ClAC) copolymer. The synthesis of binary N-VP:ClAC copolymer was performed by the radical polymerization method and then grafted to ZnPc by the Friedel Crafts acylation reaction. We have developed a water-soluble ZnPc:ClAC:N-VP photosensitizer with a narrow absorption band at 970 nm, fluorescence at λem = 825 nm and the decay fluorescence profile with 3-decay relatively longer times of 1.2 µs, 4.6 µs, and 37 µs. The concentration-dependent dark cytotoxicity investigated in normal fibroblasts (NHDF), malignant melanoma (MeWo), adenocarcinoma (HeLa), and hepatocellular carcinoma (HepG2) cell lines incubated to increased concentrations of ZnPc:ClAC:N-VP (up to 40 µM) for 24 h in the dark show low cytotoxicity. Maximum cell viability in HeLa and HepG2 tumor cell lines was observed.
