Biocompatible Tantalum Nanoparticles as Radiosensitizers for Enhancing Therapy Efficacy in Primary Tumor and Metastatic Sentinel Lymph Nodes.

Metastasis of breast carcinoma is commonly realized through lymphatic circulation, which seriously threatens the lives of breast cancer patients. Therefore, efficient therapy for both primary tumor and metastatic sentinel lymph nodes (SLNs) is highly desired to inhibit cancer growth and metastasis. During breast cancer treatment, radiotherapy (RT) is a common clinical method. However, the efficacy of RT is decreased by the radioresistance to a hypoxic microenvironment and inevitable side effects for healthy issues at high radiation doses. Considering the above-mentioned, we provide high biocompatible poly(vinylpyrrolidone) coated Ta nanoparticles (Ta@PVP NPs) for photothermal therapy (PTT) assisted RT for primary tumor and metastatic SLNs. On the one hand, for primary tumor treatment, Ta@PVP NPs with a high X-ray mass attenuation coefficient (4.30 cm2/kg at 100 keV) can deposit high radiation doses within tumors. On the other hand, for metastatic SLNs treatment, the effective delivery of Ta@PVP NPs from the primary tumor into SLNs is monitored by computed tomography and photoacoustic imaging, which greatly benefit the prognosis and treatment for metastatic SLNs. Moreover, Ta@PVP NPs-mediated PTT could enhance the RT effect, and immunogenic cell death caused by RT/PTT could induce an immune response to improve the therapeutic effect of metastatic SLNs. This study not only explores the potential of Ta@PVP NPs as effective radiosensitizers and photothermal agents for combined RT and PTT but also offers an efficient strategy to cure both primary tumor and metastatic SLNs in breast carcinoma.

Research progress and applications of silica-based aerogels - a bibliometric analysis.

Silica aerogels are three-dimensional porous materials that were initially produced in 1931. During the past nearly 90 years, silica aerogels have been applied extensively in many fields. In order to grasp the progress of silica-based aerogels, we utilize bibliometrics and visualization methods to analyze the research hotspots and the application of this important field. Firstly, we collect all the publications on silica-based aerogels and then analyze their research trends and performances by a bibliometric method regarding publication year/citation, country/institute, journals, and keywords. Following this, the major research hotspots of this area with a focus on synthesis, mechanical property regulation, and the applications for thermal insulation, adsorption, and Cherenkov detector radiators are identified and reviewed. Finally, current challenges and directions in the future regarding silica-based aerogels are also proposed.

Ultrathin, Transparent, and High Density Perovskite Scintillator Film for High Resolution X-Ray Microscopic Imaging.

Inorganic perovskite quantum dots CsPbX3 (X = Cl, Br, and I) has recently received extensive attention as a new promising class of X-ray scintillators. However, relatively low light yield (LY) of CsPbX3 and strong optical scattering of the thick opaque scintillator film restrict their practical applications for high-resolution X-ray microscopic imaging. Here, the Ce3+ ion doped CsPbBr3 nanocrystals (NCs) with enhanced LY and stability are obtained and then the ultrathin (30 µm) and transparent scintillator films with high density are prepared by a suction filtration method. The small amount Ce3+ dopant greatly enhances the LY of CsPbBr3 NCs (about 33 000 photons per MeV), which is much higher than that of bare CsPbBr3 NCs. Moreover, the scintillator films made by these NCs with high density realize a high spatial resolution of 862 nm thanks to its thin and transparent feature, which is so far a record resolution for perovskite scintillator-based X-ray microscopic imaging. This strategy not only provides a simple way to increase the resolution down to nanoscale but also extends the application of as-prepared CsPbBr3 scintillator for high resolution X-ray microscopic imaging.

A Heterojunction Structured WO2.9-WSe2 Nanoradiosensitizer Increases Local Tumor Ablation and Checkpoint Blockade Immunotherapy upon Low Radiation Dose.

Radiotherapy (RT) in practical use often suffers from off-target side effects and ineffectiveness against hypoxic tumor microenvironment (TME) as well as remote metastases. With regard to these problems, herein, we provide semiconductor heterojunction structured WO2.9-WSe2-PEG nanoparticles to realize a synergistic RT/photothermal therapy (PTT)/checkpoint blockade immunotherapy (CBT) for enhanced antitumor and antimetastatic effect. Based on the heterojunction structured nanoparticle with high Z element, the nanosystem could realize non-oxygen-dependent reactive oxygen species generation by catalyzing highly expressed H2O2 in TME upon X-ray irradiation, which could further induce immunogenic cell death. Meanwhile, this nanosystem could also induce hyperthermia upon near-infrared irradiation to enhance RT outcome. With the addition of anti-PD-L1 antibody-based CBT, our results give potent evidence that local RT/PTT upon mild temperature and low radiation dose could efficiently ablate local tumors and inhibit tumor metastasis as well as prevent tumor rechallenge. Our study provides not only one kind of radiosensitizer based on semiconductor nanoparticles but also a versatile nanoplatform for simultaneous triple-combined therapy (RT/PTT/CBT) for treating both local and metastasis tumors.

Translocation, biotransformation-related degradation, and toxicity assessment of polyvinylpyrrolidone-modified 2H-phase nano-MoS2.

Nano-MoS2 has been extensively investigated in materials science and biomedicine. However, the effects of different methods of exposure on their translocation, biosafety, and biotransformation-related degradability remain unclear. In this study, we combined the advantages of synchrotron radiation (SR) X-ray absorption near-edge structure (XANES) and high-resolution single-cell SR transmission X-ray microscopy (SR-TXM) with traditional analytical techniques to investigate translocation, precise degraded species/ratio, and correlation between the degradation and toxicity levels of polyvinylpyrrolidone-modified 2H-phase MoS2 nanosheets (MoS2-PVP NSs). These NSs demonstrated different biodegradability levels in biomicroenvironments with H2O2, catalase, and human myeloperoxidase (hMPO) (H2O2 < catalase < hMPO). The effects of NSs and their biodegraded byproducts on cell viability and 3D translocation at the single-cell level were also assessed. Toxicity and translocation in mice via intravenous (i.v.), intraperitoneal (i.p.), and intragastric (i.g.) administration routes guided by fluorescence (FL) imaging were investigated within the tested dosage. After i.g. administration, NSs accumulated in the gastrointestinal organs and were excreted from feces within 48 h. After i.v. injection, NSs showed noticeable clearance due to their decreased accumulation in the liver and spleen within 30 days when compared with that in the i.p. group, which exhibited slight accumulation in the spleen. This work paves the way for understanding the biological behaviors of nano-MoS2 using SR techniques that provide more opportunities for future applications.

Treatment of Cutting Fluid Waste using Activated Carbon Fiber Supported Nanometer Iron as a Heterogeneous Fenton Catalyst.

Addressing the problem of high chemical oxygen demands (COD) of cutting fluid waste generated in the machining process, its complex composition, and the specific conditions required for the treatment process, a heterogeneous Fenton fibre catalyst (NZVI@ACF) made of nanometer-iron supported on activated carbon fiber using dip-molding was developed. NZVI was homogeneously loaded onto ACF surfaces to form NZVI@ACF, with a specific surface area (SBET) of 726.3642 m2/g. Using a multistage chemical pretreatment, the NZVI@ACF/H2O2 system was used to effectively treat cutting fluid waste. The results indicated that the rate of COD removal in the cutting fluid waste liquid pretreated with NZVI@ACF/H2O2 system was 99.8% when the reactions conditions were optimized to 20 nmol/L H2O2, 6 g/L NZVI@ACF, total reaction time of 120 min and pH 5. The treated waste solution passed China's tertiary wastewater discharge standards. NZVI@ACF/H2O2 demonstrated an excellent catalytic performance compared to the traditional Fenton catalyst, increased the effective pH reaction range and had an adsorption effect on the waste liquid after the reaction.

Cu2(OH)PO4/reduced graphene oxide nanocomposites for enhanced photocatalytic degradation of 2,4-dichlorophenol under infrared light irradiation.

Sparked by the growing environmental crises, photocatalytic degradation of chlorophenols with inexhaustible solar energy is expected to be converted into actual applications. Here, we report the preparation of the nanocomposite of Cu2(OH)PO4 and reduced graphene oxide (Cu2(OH)PO4/rGO) through a one-step hydrothermal method and examined its infrared-light photocatalytic activity in the degradation of 2,4-dichlorophenol (2,4-DCP). As evidenced by the absorption spectra and the degradation of 2,4-DCP, Cu2(OH)PO4/rGO exhibited enhanced infrared light-driven photocatalytic activity compared to pure Cu2(OH)PO4 and was very stable even after repeated cycling. More importantly, the introduction of hydrogen peroxide (H2O2) could combine the photocatalytic and photo-Fenton effects into one reaction system and maximize the infrared light photocatalytic efficiency. Typically, the rate constant of Cu2(OH)PO4/rGO and H2O2 was more than 6.25 times higher than that of only Cu2(OH)PO4/rGO, and almost 10 times greater than the value for pure Cu2(OH)PO4. Further, a plausible mechanism for the enhanced photocatalytic properties of Cu2(OH)PO4/rGO has been discussed. These findings may help the development of novel hybrid photocatalysts with enhanced infrared light photocatalytic activity for applications in the treatment of chlorophenol-contaminated wastewater.

Mesoporous Bamboo Charcoal Nanoparticles as a New Near-Infrared Responsive Drug Carrier for Imaging-Guided Chemotherapy/Photothermal Synergistic Therapy of Tumor.

Near-infrared-(NIR)-light-triggered photothermal nanocarriers have attracted much attention for the construction of more smart and effective therapeutic platforms in nanomedicine. Here, a multifunctional drug carrier based on a low cost, natural, and biocompatible material, bamboo charcoal nanoparticles (BCNPs), which are prepared by the pyrolysis of bamboo followed by physical grinding and ultrasonication is reported. The as-prepared BCNPs with porous structure possess not only large surface areas for drug loading but also an efficient photothermal effect, making them become both a suitable drug carrier and photothermal agent for cancer therapy. After loading doxorubicin (DOX) into the BCNPs, the resulting DOX-BCNPs enhance drug potency and more importantly can overcome the drug resistance of DOX in a MCF-7 cancer cell model by significantly increasing cellular uptake while remarkably decreasing drug efflux. The in vivo synergistic effect of combining chemotherapy and photothermal therapy in this drug delivery system is also demonstrated. In addition, the BCNPs enhance optoacoustic imaging contrast due to their high NIR absorbance. Collectively, it is demonstrated that the BCNP drug delivery system constitutes a promising and effective nanocarrier for simultaneous bioimaging and chemo-photothermal synergistic therapy of cancer.