RESUMO
Mosquitoes are significant vectors, responsible for transmitting serious infectious diseases, including the recent epidemics of global significance caused by, for example, Zika, Dengue and Chikungunya viruses. The chemical insecticides in use for mosquito control are toxic and ineffective due to the development of resistance to them. The new approach to reduce mosquito population by releasing genetically modified males to cause female infertility is still under environmental safety evaluation. Photodynamic insecticides (PDI) have long been known as a safe and effective alternative by using dyes as the photosensitizers (PS) for activation with light to generate insecticidal singlet oxygen and reactive oxygen species. This approach warrants re-examination with advances in the chemical synthesis of novel PS, e.g. phthalocyanines (PC). Nine PC were compared with five porphyrin derivatives and two classic PS of halogenated fluoresceins, i.e. cyanosine and rose bengal experimentally for photodynamic treatment (PDT) of the larvae of laboratory-reared Aedes mosquitoes and their cell lines. Groups of 2nd instar larvae were first exposed overnight to graded concentrations of each PS in the dark followed by their exposure to dim light for up to 7 hours. Larvae of both experimental and control groups were examined hourly for viability based on their motility. Monolayers of mosquito cells were similarly PS-sensitized and exposed briefly to light at the PS-specific excitation wavelengths. Cell viability was assessed by MTT reduction assays. Of the 16 PS examined for photodynamic inactivation of the mosquito larvae, effective are three novel PC, i.e. amino-Si-PC1 and -PC2, anilinium Zn-PC3.4, pyridyloxy Si-PC14 and two porphyrin derivatives, i.e. TPPS2 and TMAP. Their EC50 values were determined, all falling in the nanomolar range lower than those of rose bengal and cyanosine. All PS effective in vivo were also found to dose-dependently inactivate mosquito cells photodynamically in vitro, providing cellular basis for their larvicidal activities. The present findings of novel PC with effective photodynamic larvicidal activities provide fresh impetus to the development of PDI with their established advantages in safety and efficacy. Toward that end, the insect cell lines are of value for rapid screening of new PC. The optimal excitability of PC with insect-invisible red light is inferred to have the potential to broaden the range of targetable insect pests.
Assuntos
Indóis/farmacologia , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Aedes/efeitos dos fármacos , Animais , Indóis/metabolismo , Inseticidas/metabolismo , Isoindóis , Larva/efeitos dos fármacos , Mosquitos Vetores/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologiaRESUMO
An unsymmetrical phthalocyanine conjugated with an RGDyK moiety (6) was synthesized and characterized. Its photophysical properties, including electronic absorption, fluorescence emission (ΦF = 0.20), singlet oxygen quantum yield (ΦΔ = 0.63) and two-photon absorption cross section (TPACS) at different wavelengths were studied. The in vitro cell study data demonstrate that this Pc conjugate possesses significantly high cellular uptake toward the ανß3 positive DU145 prostate cancer cells along with an efficient photocytotoxicity (IC50 = 0.04 µM), showing this compound is one of the most promising photosensitizers for targeting photodynamic therapy (PDT) of cancer.
Assuntos
Indóis/química , Oligopeptídeos/química , Fotoquimioterapia , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Humanos , Técnicas In Vitro , Isoindóis , Espectroscopia de Ressonância Magnética , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
To demonstrate the effect of axial ligands on the structure-activity relationship, a series of axially substituted silicon phthalocyanines (SiPcs) have been synthesized with changes to the axial ligands. The reactivity of the axial ligand upon shielding by the phthalocyanine ring current, along with their stability, photophysical, and photodynamic therapy (PDT) activities were compared and evaluated for the first time. As revealed by single-crystal XRD analysis, rotation of the axial -OMe ligands was observed in SiPc 3, which resulted in two molecular configurations coexisting synchronously in both the solid and solution states and causing a split of the phthalocyanine α protons in the (1)H NMR spectra that is significantly different from all SiPcs reported so far. The remarkable photostability, good singlet oxygen quantum yield, and efficient in vitro photodynamic activity synergistically show that compound 3 is one of the most promising photosensitizers for PDT.
Assuntos
Indóis/química , Indóis/farmacologia , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Indóis/síntese química , Ligantes , Estrutura Molecular , Compostos de Organossilício/síntese química , Fármacos Fotossensibilizantes/síntese química , Oxigênio Singlete/química , Relação Estrutura-AtividadeRESUMO
A hydrophilic near-infrared (NIR) photosensitizer featuring a naphthalocyanine core and peripheral carboxylate acid groups was synthesized and characterized. Its photophysical and photochemical properties were studied and compared with phthalocyanine. Due to the extended π-conjugation, both the Q band and fluorescence emit of this naphthalocyanine bathochromically shift to NIR region. It also exhibits superior NIR photodynamic efficiency to phthalocyanine as evidenced by high efficiency in generating singlet oxygen (ΦΔ=0.66) and in vitro phototoxicity toward Hela human cervical cancer cells. Therefore, this novel naphthalocyanine could potentially be a NIR photosensitizer for photodynamic therapy.
Assuntos
Raios Infravermelhos , Compostos Organometálicos/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Células HeLa , Humanos , Microscopia de Fluorescência , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/químicaRESUMO
Nestlike 3D ZnO porous structures with size of 1.0-3.0 µm have been synthesized through annealing the zinc hydroxide carbonate precursor, which was obtained by a one-pot hydrothermal process with the assistance of glycine, Na(2)SO(4), and polyvinyl pyrrolidone (PVP). The nestlike 3D ZnO structures are built of 2D nanoflakes with the thickness of ca. 20 nm, which exhibit the nanoporous wormhole-like characteristic. The measured surface area is 36.4 m(2)g(-1) and the pore size is ca. 3-40 nm. The unique nestlike 3D ZnO porous structures provided large contacting surface area for electrons, oxygen and target gas molecules, and abundant channels for gas diffusion and mass transport. Gas sensing tests showed that the nestlike 3D ZnO porous structures exhibit excellent gas sensing performances such as high sensitivity and fast response and recovery speed, suggesting the potential applications as advanced gas sensing materials.