RESUMO
New multifunctional nanospheres have been designed and synthesized through a green and facile strategy, which could be readily used in multi-modality tumor imaging through near-infrared fluorescence (NIRF) imaging, magnetic resonance imaging (MRI) and computed tomography (CT) imaging. Such nanospheres are made of porous superparamagnetic Zn1/3Fe8/3O4 nanosphere cores covered by a thin layer shell of Ag clusters. While the shell of Ag clusters provides efficient NIRF imaging, the Zn1/3Fe8/3O4 nanosphere cores allow external magnetic manipulation and readily facilitates their utilization for MRI and CT imaging.
RESUMO
Human life toll by cancer, one of the highest among most dreaded diseases in advanced societies, could be reduced by implementing evidence-based strategies for its prevention, early diagnosis and assessment of the progress and suitability of therapies by fast and non-invasive methods. In this contribution, a novel strategy is reported for highly sensitive recognition and in vivo imaging of cancer cells taking advantage of their spontaneous ability to generate silver nanoclusters (NCs) with high near-infrared fluorescence emission by intracellular reduction of innocuous silver salts. Both ex vivo experiments comparing cancer cell models to normal cells and in vivo imaging of subcutaneous xenografted tumor (cervical carcinoma model) in nude mice established the validity of this strategy for precise and selective imaging of cells and tumors. Furthermore, it was observed that the spontaneous self-generation of Ag NCs by tumors in their inside led to drastic reduction of their sizes and often to complete remission, thus providing important hope for new therapy strategies based on cheap and readily available agents.
Assuntos
Antineoplásicos/farmacologia , Carcinoma/diagnóstico , Diagnóstico por Imagem/métodos , Nanopartículas Metálicas/química , Nitrato de Prata/química , Neoplasias do Colo do Útero/diagnóstico , Animais , Antineoplásicos/síntese química , Carcinoma/patologia , Carcinoma/terapia , Linhagem Celular Tumoral , Feminino , Glutationa/química , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Espectroscopia de Luz Próxima ao Infravermelho , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/terapia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
This article demonstrates a versatile method to prepare the hollow PbS nanospheres via the template method. First, the latex poly (vinyl benzyl chloride) (PVBC) nanoparticles were synthesized by the radical polymerization, followed by the atom transfer reversible polymerization of lead (II) dimethacrylate (Pb (MA)2) on the surfaces of the latex nanoparticles. Then, the ethanethioamide was reacted with the nanoparticles to afford the PbS. By calcination at 600°C for 6 h, the template was removed to obtain the hollow PbS nanospheres. The structure, morphology and optical properties of the hollow PbS nanospheres were carefully investigated. The received hollow PbS nanospheres could be used for the controlled release of phenol after absorbing phenol solution.
RESUMO
Multidrug resistance (MDR) of bacteria is still an unsolved serious problem to threaten the health of human beings. Developing new antibacterial agents, therefore, are urgently needed. Herein, we have explored the possibility to design and synthesize some novel antibacterial agents including ferrocene-substituted carborane derivative (Fc(2)SBCp(1)) and have evaluated the relevant antibacterial action against two clinical common MDR pathogens (i.e., Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa) in vitro and in vivo. The results demonstrate that in vitro antimicrobial activity of Fc(2)SBCp(1) could be gradually transformed into a bactericidal effect from a bacteriostatic effect with the increasing concentration of the active carborane derivative, which can also prevent biofilm formation at concentrations below MIC (i.e., minimal inhibitory concentration). Biocompatibility studies indicate that there exists no/or little toxic effect of Fc(2)SBCp(1) on normal cells/tissues and leads to little hemolysis. In vivo studies illustrate that the new carborane derivative Fc(2)SBCp(1) is highly effective in treating bacteremia caused by S. aureus and P. aeruginosa as well as interstitial pneumonia caused by S. aureus. This raises the possibility for the potential utilization of the new ferrocene-substituted carborane derivatives as promising antibacterial therapeutic agents against MDR bacterial infections in future clinical applications.