Starvation-Sensitized and Oxygenation-Promoted Tumor Sonodynamic Therapy by a Cascade Enzymatic Approach

The therapeutic outcomes of noninvasive sonodynamic therapy (SDT) are always compromised by tumor hypoxia, as well as inherent protective mechanisms of tumor. Herein, we report a simple cascade enzymatic approach of the concurrent glucose depletion and intratumoral oxygenation for starvation-sensitized and oxygenation-amplified sonodynamic therapy using a dual enzyme and sonosensitizer-loaded nanomedicine designated as GOD/CAT@ZPF-Lips. In particular, glucose oxidase- (GOD-) catalyzed glycolysis would cut off glucose supply within the tumor, resulting in the production of tumor hydrogen peroxide (H2O2) while causing tumor cells starvation. The generated H2O2 could subsequently be decomposed by catalase (CAT) to generate oxygen, which acts as reactants for the abundant singlet oxygen (1O2) production by loaded sonosensitizer hematoporphyrin monomethyl ether (HMME) upon the US irradiation, performing largely elevated therapeutic outcomes of SDT. In the meantime, the severe energy deprivation enabled by GOD-catalyzed glucose depletion would prevent tumor cells from executing protective mechanisms to defend themselves and make the tumor cells sensitized and succumbed to the cytotoxicity of 1O2. Eventually, GOD/CAT@ZPF-Lips demonstrate the excellent tumoral therapeutic effect of SDT in vivo without significant side effect through the cascade enzymatic starvation and oxygenation, and encouragingly, the tumor xenografts have been found completely eradicated in around 4 days by the intravenous injection of the nanomedicine without reoccurrence for as long as 20 days

Inert filler selection strategies in Li-ion gel polymer electrolytes

The main role of inert fillers in polymer electrolytes is to enhance ionic conductivity. However, lithium ions in gel polymer electrolytes (GPEs) conduct in liquid solvent rather than along the polymer chains. So far, the main role of inert fillers in improving the electrochemical performance of GPEs is still unclear. Here, various low-cost and common inert fillers (Al2O3, SiO2, TiO2, ZrO2) are introduced into GPEs to study their effects on Li-ion polymer batteries. It is found that the addition of inert fillers has different effects on ionic conductivity, mechanical strength, thermal stability, and, dominantly, interfacial properties. Compared with other gel electrolytes containing SiO2, TiO2, or ZrO2 fillers, those with Al2O3 fillers exhibit the most favorable performance. The high performance is ascribed to the interaction between the surface functional groups of Al2O3 and LiNi0.8Co0.1Mn0.1O2, which alleviates the decomposition of the organic solvent by the cathode, resulting in the formation of a high-quality Li+ conductor interfacial layer. This study provides an important reference for the selection of fillers in GPEs, surface modification of separators, and cathode surface coating.Ministry of Education (MOE)Submitted/Accepted versionThis work is financially supported from the Ministry of Education, Singapore, by its Academic Research Fund Tier 2 (MOE-T2EP50121-0006), and by the National Nature Science Foundation of China (No. 22209199)

Solvothermal-Induced 3D Macroscopic SnO₂/Nitrogen-Doped Graphene Aerogels for High Capacity and Long-Life Lithium Storage

3D macroscopic tin oxide/nitrogen-doped graphene frameworks (SnO₂/GN) were constructed by a novel solvothermal-induced self-assembly process, using SnO₂ colloid as precursor (crystal size of 3–7 nm). Solvothermal treatment played a key role as N,N-dimethylmethanamide (DMF) acted both as reducing reagent and nitrogen source, requiring no additional nitrogen-containing precursors or post-treatment. The SnO₂/GN exhibited a 3D hierarchical porous architecture with a large surface area (336 m²g^‑1), which not only effectively prevented the agglomeration of SnO₂ but also facilitated fast ion and electron transport through 3D pathways. As a result, the optimized electrode with GN content of 44.23% exhibited superior rate capability (1126, 855, and 614 mAh g^‑1 at 1000, 3000, and 6000 mA g^‑1, respectively) and extraordinary prolonged cycling stability at high current densities (905 mAh g^‑1 after 1000 cycles at 2000 mA g^‑1). Electrochemical impedance spectroscopy (EIS) and morphological study demonstrated the enhanced electrochemical reactivity and good structural stability of the electrode

Intratumoral synthesis of nano-metalchelate for tumor catalytic therapy by ligand field-enhanced coordination

Iron gall chelate (GA-Fe) can promote oxygen reduction reactions and reactive oxygen species generation which causes chemical corrosion. Here, the authors, inspired by this phenomenon, develop a composite nanomedicine for tumour therapy constructed by loading gallate into Fe-engineered and PEGylated mesoporous silica nanocarrier, and show that it inhibits tumour growth

Association between population density and infection rate suggests the importance of social distancing and travel restriction in reducing the COVID-19 pandemic

International audienceCurrently, 2019-nCoV has spread to most countries of the world. Understanding the environmental factors that affect the spreadof the disease COVID-19 infection is critical to stop the spread of the disease. The purpose of this study is to investigate whetherpopulation density is associated with the infection rate of the COVID-19. We collected data from official webpages of cities inChina and in the USA. The data were organized on Excel spreadsheets for statistical analyses. We calculated the morbidity andpopulation density of cities and regions in these two countries. We then examined the relationship between morbidity and otherfactors. Our analysis indicated that the population density in cities in Hubei province where the COVID-19 was severe wasassociated with a higher percentage of morbidity, with an r value of 0.62. Similarly, in the USA, the density of 51 states andterritories is also associated with morbidity from COVID-19 with an r value of 0.55. In contrast, as a control group, there is noassociation between the morbidity and population density in 33 other regions of China, where the COVID-19 epidemic is wellunder control. Interestingly, our study also indicated that these associations were not influenced by the first case of COVID-19.The rate of morbidity and the number of days from the first case in the USA have no association, with an r value of − 0.1288.Population density is positively associated with the percentage of patients with COVID-19 infection in the population. Our datasupport the importance of such as social distancing and travel restriction in the prevention of COVID-19 spread

Template-Free Synthesis of Hollow/Porous Organosilica–Fe₃O₄ Hybrid Nanocapsules toward Magnetic Resonance Imaging-Guided High-Intensity Focused Ultrasound Therapy

Entirely differing from the common templating-based multistep strategy for fabricating multifunctional hollow mesoporous silica nanoparticles (HMSN), a facile and template-free synthetic strategy has been established to construct a unique hollow/mesoporous organosilica nanocapsule (OSNC) concurrently encapsulating both isopentyl acetate (PeA) liquid and superparamagnetic iron oxides inside (denoted as PeA@OSNC). This novel material exhibits ultrasmall and uniform particle size (∼82 nm), high surface area (∼534 m²·g^–1), and excellent colloidal stability in aqueous solution. The oil-phase PeA with relatively low boiling point (142 °C) and high volatility not only plays a crucial role in formation of a large hollow cavity from the viewpoint of structural design but also enables the PeA@OSNC to act as an efficient enhancement agent in high-intensity focused ultrasound (HIFU) therapy. Moreover, the unique satellite-like distribution of Fe₃O₄ nanoparticles (NP) on the organosilica shell offered excellent magnetic resonance imaging (MRI) contrast capability of PeA@OSNC in vitro and in vivo. More importantly, such a novel theranostic agent has favorable biosafety, which is very promising for future clinical application in MRI-guided HIFU therapy

“Manganese Extraction” Strategy Enables Tumor-Sensitive Biodegradability and Theranostics of Nanoparticles

Biodegradability of inorganic nanoparticles is one of the most critical issues in their further clinical translations. In this work, a novel “metal ion-doping” approach has been developed to endow inorganic mesoporous silica-based nanoparticles with tumor-sensitive biodegradation and theranostic functions, simply by topological transformation of mesoporous silica to metal-doped composite nanoformulations. “Manganese extraction” sensitive to tumor microenvironment was enabled in manganese-doped hollow mesoporous silica nanoparticles (designated as Mn-HMSNs) to fast promote the disintegration and biodegradation of Mn-HMSNs, further accelerating the breakage of Si–O–Si bonds within the framework. The fast biodegradation of Mn-HMSNs sensitive to mild acidic and reducing microenvironment of tumor resulted in much accelerated anticancer drug releasing and enhanced T₁-weighted magnetic resonance imaging of tumor. A high tumor-inhibition effect was simultaneously achieved by anticancer drug delivery mediated by PEGylated Mn-HMSNs, and the high biocompatibility of composite nanosystems was systematically demonstrated in vivo. This is the first demonstration of biodegradable inorganic mesoporous nanosystems with specific biodegradation behavior sensitive to tumor microenvironment, which also provides a feasible approach to realize the on-demand biodegradation of inorganic nanomaterials simply by “metal ion-doping” strategy, paving the way to solve the critical low-biodegradation issue of inorganic drug carriers