RESUMO
Inadvertent photosensitizer-activation and singlet-oxygen generation hampers clinical application of photodynamic therapies of superficial tumors or subcutaneous infections. Therefore, a reversible photoswitchable system was designed in micellar nanocarriers using ZnTPP as a photosensitizer and BDTE as a photoswitch. Singlet-oxygen generation upon irradiation didnot occur in closed-switch micelles with ZnTPP/BDTE feeding ratios >1:10. Deliberate switch closure/opening within 65-80 min was possible through thin layers of porcine tissue in vitro, increasing for thicker layers. Inadvertent opening of the switch by simulated daylight, took several tens of hours. Creating deliberate cell damage and prevention of inadvertent damage in vitro and in mice could be done at lower ZnTPP/BDTE feeding ratios (1:5) in open-switch micelles and at higher irradiation intensities than inferred from chemical clues to generate singlet-oxygen. The reduction of inadvertent photosensitizer activation in micellar nanocarriers, while maintaining the ability to kill tumor cells and infectious bacteria established here, brings photodynamic therapies closer to clinical application.
Assuntos
Nanoestruturas/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Oxigênio Singlete/metabolismo , Células 3T3 , Animais , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Feminino , Células HeLa , Humanos , Lactonas/química , Camundongos , Camundongos Endogâmicos BALB C , Micelas , Fármacos Fotossensibilizantes/administração & dosagem , Polietilenoglicóis/química , Porfirinas/química , Oxigênio Singlete/química , Espectrofotometria Ultravioleta , Zinco/químicaRESUMO
Making the substrates form highly dense, homogeneous, and stable hotspots regions is important for the sensitive detection of surface-enhanced Raman spectroscopy (SERS). A new strategy based on solvent-induced (SI) SERS substrate to form a stable interval of the hotspot for detection was explored and the enhancement factor (EF) of our SERS substrates could reach about 1.4 × 109. By preferential adsorption of alcohol solutions by Q-Sepharose microsphere (QSS) in mixed water and alcohol solutions, the size of QSS@AuNPs was dynamically adjusted and the spacing between gold nanoparticles (AuNPs) was adjusted to keep the substrate in the optimal hotspot mode for the sensitive detection of SERS in the liquid state. As a real application case, such a SI-SERS strategy was employed to determine SCN- in saliva and a limit of detection (LOD) of about 10-10 M could be achieved.
Assuntos
Ouro/química , Nanopartículas Metálicas/química , Saliva/química , Sefarose/química , Tiocianatos/análise , Humanos , Microesferas , Tamanho da Partícula , Solventes/química , Análise Espectral Raman , Propriedades de SuperfícieRESUMO
Long-term exposure to nicotine causes a variety of human diseases, such as lung damage/adenocarcinoma, nausea and vomiting, headache, incontinence and heart failure. In this work, as a surface-enhanced Raman scattering (SERS) substrate, zinc oxide (ZnO) tips decorated with gold nanoparticles (AuNPs) are fabricated and designated as ZnO/Au. Taking advantage of the synergistic effect of a ZnO semiconductor with morphology of tips and AuNPs, the ZnO/Au-based SERS assay for nicotine demonstrates high sensitivity and the limit of detection 8.9 × 10-12 mol/L is reached, as well as the corresponding linear dynamic detection range of 10-10-10-6 mol/L. Additionally, the signal reproducibility offered by the SERS substrate could realize the reliable determination of trace nicotine in saliva.
Assuntos
Nanopartículas Metálicas , Nicotina/análise , Óxido de Zinco , Ouro , Humanos , Reprodutibilidade dos Testes , Saliva/química , Análise Espectral RamanRESUMO
Using agarose coated gigaporous polystyrene microspheres as a base support, a novel anion exchanger (DEAE-AP) has been developed after functionalization with diethylaminoethyl chloride. The gigaporous structure, static adsorption behavior, and chromatographic properties of DEAE-AP medium were characterized and compared with those of commercially available resin DEAE Sepharose Fast Flow (DEAE-FF). The results implied that there existed some through pores in DEAE-AP microspheres, which effectively reduced resistance to stagnant mobile phase mass transfer by inducing convective flow of mobile phase in the gigapores of medium. As a consequence, the column packed with DEAE-AP exhibited low column backpressure, high column efficiency, high dynamic binding capacity and high protein resolution at high flow velocity up to 2600cm/h. In conclusion, all the results suggested that the gigaporous absorbent is promising for high-speed protein chromatography.