A novel microwave stimulus remote-controlled anticancer drug release system based on Janus TiO2-x&mSiO2 nanocarriers.

In this work, we used a simple method to construct Janus-shaped TiO2-x&mSiO2 nanoparticles composed of gray-black titanium dioxide (TiO2-x) and mesoporous silica (mSiO2) serving as carriers to improve the microwave-controlled release performance. In the composite materials, on one hand, the rod-shaped mSiO2 could realize high-efficiency drug loading, on the other hand, spherical TiO2-x featuring oxygen vacancy acted as the main microwave absorber. The overall spatial separation between titanium dioxide and silicon dioxide was crucial to enhance microwave conversion efficiency. The Janus-liked nanomaterial was made up of TiO2-x nanosphere with a diameter of approximately 180 nm on one end and rod-shaped mesoporous silica with about 220 nm in length and 100 nm in diameter on the other end, and the specific surface area of the entire material was 203.25 m2/g. Meanwhile, the cumulative doxorubicin hydrochloride (DOX) loading rate of the carrier reached up to 38 wt% after 24 h. The loading process of the DOX was exothermic, and the noncovalent interaction between the DOX and Janus TiO2-x&mSiO2 carrier was mainly van der Waals force. Furthermore, the rates of drug release at 24 h were up to 61 wt%, 69 wt% and 89 wt% at pH 7.0, 5.0 and 3.0, respectively. After microwave stimulation at pH 7.0, the rate of drug release increased observably from 61% to 88% compared to that of non-microwave irradiation. The order of the microwave thermal conversion capability of the samples was Janus TiO2-x&mSiO2 > Janus TiO2&mSiO2 > core-shell TiO2-x@mSiO2. Besides, cytotoxicity tests indicated that Janus TiO2-x&mSiO2 nanoparticles had good biocompatibility. Therefore, the multifunctional carrier of the Janus-shaped configuration could not only release drugs under pH control, but also be further triggered by microwave stimulation. The Janus-shaped TiO2-x&mSiO2 nanoparticles will look forward to laying foundation to the application in drug delivery systems.

Photo-Fenton Degradation of Organic Dyes Based on a Fe3O4 Nanospheres/Biomass Composite Loaded Column.

In order to deal with pollution of organic dyes, magnetic Fe3O4 nanospheres (NPs) with an average diameter of 202 ± 0.5 nm were synthesized by a solvothermal method at 200 °C, and they can efficiently degrade organic dyes (methylene blue (MB), rhodamine B (RhB) and xylenol orange (XO)) aqueous solutions (20 mg/L) within 1 min. Based on this Fenton reagent, Fe3O4 NPs/biomass composite degradation column was made using sawdust as substrate, and it can efficiently degrade organic dyes continually. More importantly, the composite can be regenerated just by an ultrasonic treatment, and its degradation performance almost remains the same.