Song Shen,Lin Wu,Jiejie Liu,Meng Xie,Haijun Shen,Xueyong Qi,Yongmin Yan,Yanru Ge,Yi Jin
To facilitate targeting drug delivery and combined therapy, we develop titanium dioxide-encapsulated Fe 3 O 4 nanoparticles (Fe 3 O 4 @TiO 2 NPs). Titanium dioxide (TiO 2 ), which is employed as a sonosensitizer for sonodynamic therapy (SDT), can also be used for the loading of doxorubicin (DOX). The fabricated Fe 3 O 4 @TiO 2 NPs exhibit pH-dependent loading and release of doxorubicin (DOX) in vitro. After incubation with cancer cells, reactive oxygen species (ROS) are generated efficiently upon the irradiation of ultrasound. In the biodistribution experiments, extremely high in vivo tumor accumulation of Fe 3 O 4 @TiO 2 NPs and long-time retention effect are observed. Compared with chemotherapy or sonodynamic treatment alone, the combined therapy demonstrated a synergistic effect, resulting in stronger cytotoxicity and higher therapeutic efficacy. Thus, the constructed NPs are endowed with multifunctions which allow them to selectively deliver combinatorial therapeutic payload to tumor with enhanced therapeutic effectiveness and minimal side effects.
In recent years, nanoscale particles have been applied in the utilisation of solar energy due to their excellent properties. In light of the multiple functions of composite nanoparticles, some solar-assisted systems have been developed and exhibited comprehensive photoelectric and photo-thermal transformation effects. However, the presence of nanoparticles in these systems can cause secondary pollution and severely limit large-scale application of the solar technology. Herein we developed a recyclable photo-thermal conversion and purification system based on Fe 3 O 4 nanoparticles decorated with TiO 2 nanoparticles, which could be separated from water under the action of a magnetic force. Under the solar illumination power of 1 sun (1 sun = 1000 W·m −2 ), thermal receiver efficiency of 76.4% and Rhodamine B degradation efficiency of 85% were obtained with a 0.1 g/L Fe 3 O 4 @TiO 2 nanofluid. With the increase of the solar illumination power, the degradation efficiency has been increased to 94%. The recovery rate and efficiency could be controlled by adjusting the magnetic field strength and the magnetic property of Fe 3 O 4 @TiO 2 nanoparticles. This study provides an approach to not only significantly reduce material consumption in the design of solar devices, but also to realise broad solar energy applications for water purification and photo-thermal conversion.
Quantitative detection of phospholipids at the single cell level remains in challenge. Herein, the TiO 2 -coated Fe 3 O 4 nanoparticles were synthesized to selectively enrich trace phospholipids from single cell, which were then eluted using 1.5% ammonia/methanol (w/w) for sensitive detection by electrospray ionization mass spectrometry . Under the optimal experimental conditions, eighteen phospholipids in single cell samples were detected and identified by MS/MS experiments. The limit-of-detections (LODs) were 0.012 μ g/L for phosphatidylcholine (PC, 34:1) and 0.014 μ g/L for phosphatidylcholine (PC, 36:2) in PBS matrix, with the linear range of 0.05–50 μ g/L ( R 2 ≥ 0.999). The recovery rates of 94.90–104.00% were obtained, with the relative standard deviations (RSDs ≤ 6.90%). Quantitative determination of PC in real unicellular samples was also achieved, with the concentration of 1.82–2.11 μ g/L for PC(34:1) and 1.25–1.65 μ g/L for PC(36:2) in six types of single cell, opening up possibilities for quantitative analysis of trace compounds in complex bio-samples. A set of 6 types of tumor cells were analyzed and further differentiated by the partial least squares-discriminant analysis (PLS-DA). Conclusively, a facile method for the direct quantification of phospholipids in single cell samples has been developed, showing potential applications for advanced investigation of phosphorylated substance at the single cell level.