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Scheme of preparation of PTX/PECNGel and local injection for chemotherapy in vivo.

Blood-Brain Barrier (BBB) can be opened locally, noninvasively and reversibly by low frequency focused ultrasound (FUS) in the presence of microbubbles. In this study, Evans blue (EB) dye extravasation across BBB was enhanced by 1 MHz FUS at acoustic pressure of 0.35MPa in the presence of microbubbles at clinically comparable dosage. The spatial distribution of EB extravasation was visualized using fluorescence imaging method. The center region of BBB disruption area showed more enhanced fluorescence signal than the surrounding region in general. However, EB dye deposition was heterogeneous in the center region. The findings in this study indicated potential use of fluorescence imaging to evaluate large molecules delivery across BBB.

An efficient theranostic nanoplatform responding to tumour microenvironments with characters of simple and flexible combinations owns great potential in cancer diagnosis and therapy.

As giant magnetostrictive material, TbDyFe is regarded as a promising choice for magnetic sensing due to its excellent sensitivity to changes in magnetic fields. To satisfy the requirements of high sensitivity and the stability of magnetic sensors, TbDyFe thin films were successfully deposited on single-crystal diamond (SCD) substrate with a Young’s modulus over 1000 GPa and an ultra-stable performance by radio-frequency magnetron sputtering at room temperature. The sputtering power and deposition time effects of TbDyFe thin films on phase composition, microstructure, and magnetic properties were investigated. Amorphous TbDyFe thin films were achieved under various conditions of sputtering power and deposition time. TbDyFe films appeared as an obvious boundary to SCD substrate as sputtering power exceeded 100 W and deposition time exceeded 2 h, and the thickness of the films was basically linear with the sputtering power and deposition time based on a scanning electron microscope (SEM). The film roughness ranged from 0.15 nm to 0.35 nm, which was measured by an atomic force microscope (AFM). The TbDyFe film prepared under a sputtering power of 100 W and a deposition time of 3 h possessed the coercivity of 48 Oe and a remanence ratio of 0.53, with a giant magnetostriction and Young’s modulus effect, suggesting attractive magnetic sensitivity. The realization of TbDyFe/SCD magnetic material demonstrates a foreseeable potential in the application of high-performance sensors.

Focused ultrasound (FUS) combined with microbubbles is an attractive method to deliver therapeutic agents to brain tissue noninvasively, transiently and locally such as antibodies, gene vectors, liposomal drugs. The objective of this study is to investigate passive delivery outcome of liposomes after ultrasound mediated blood-brain barrier (BBB) disruption. Microbubbles were injected intraveneously through mice tail vein at 0.1 μL/g. Focused ultrasound (center frequency: 1.2819 MHz) was applied to mice brains with 10 ms pulse length and 1 Hz repetition frequency at acoustic power 1.1 W for 60 s. After sonication, 55-nm and 120-nm rhodamine-labeled liposomes were administered to mice intraveneously. Fluorescence imaging of brain coronal sections showed that the spatial distribution of delivered liposomes across BBB was characterized by scattered spots and heterogeneous. However, the quantitative analysis results indicated that passive deliveries of liposomes across BBB were confined, especially for 120-nm liposomes.

Energy absorption for AZ31 magnesium Alloy was investigated with Split Hopkinson Pressure Bar using single stress wave so as to avoid multiple stress wave loading. The stress wave amplitude, which was in elastic stress range and propagated along the AZ31 magnesium bar, was reduced with increasing propagating distance, and with increasing stress wave amplitude, the stress wave amplitude reduction along the magnesium bar was increased losing more energy as compared with that of the stress wave with lower amplitude. The drastically decreased stress wave amplitude could be explained based on dislocations movements, which was similar to the established theory of damping for the explanation of the energy loss during cyclic loading. However, it was not the case for LY12 aluminum alloy: the stress wave amplitude changed slightly without drastic energy loss regardless of the variation of stress wave amplitude.