Zinc-air batteries offer a possible solution for large-scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni-doped CoO nanosheets (NSs) for zinc-air batteries with superior high power density/energy density and durability is reported for the first time. In micro- and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O2 diffusion and a high electrocatalytic active surface area. In atomic scale, Ni doping significantly enhances the intrinsic oxygen reduction reaction activity per active site. As a result of controlled multiscale structure, the primary zinc-air battery with engineered Ni-doped CoO NSs electrode shows excellent performance with a record-high discharge peak power density of 377 mW cm-2 , and works stable for >400 h at 5 mA cm-2 . Rechargeable zinc-air battery based on Ni-doped CoO NSs affords an unprecedented small charge-discharge voltage of 0.63 V, outperforming state-of-the-art Pt/C catalyst-based device. Moreover, it is shown that Ni-doped CoO NSs assembled into all-solid-state coin cells can power 17 light-emitting diodes and charge an iPhone 7 mobile phone.
The surface charge of nanocarriers inevitably affects drug delivery efficiency; however, the cancer cell specificity, anti-inflammatory effects, and charge-reversal points remain to be further addressed in biomedical applications. The aim of this study was to comprehensively assess the cancer cell specificity of DOX-loaded mesoporous silica-chitosan oligosaccharide-carboxymethyl chitosan nanoparticles (DOX@MSNs-COS-CMC) in MCF-7 and HeLa cells, inhibit the production of inflammatory cytokines, and improve the drug accumulation in the tumor site. Intracellular results reveal that the retention time prolonged to 48 h in both HeLa and MCF-7 cells at pH 7.4. However, DOX@MSNs-COS-CMC exhibited a cell type-dependent cytotoxicity and enhanced intracellular uptake in HeLa cells at pH 6.5, due to the clathrin-mediated endocytosis and macropinocytosis in HeLa cells in comparison with the vesicular transport in MCF-7 cells. Moreover, Pearson's correlation coefficient value significantly decreased to 0.25 after 8 h, prompting endosomal escape and drug delivery into the HeLa nucleus. After the treatment of MSNs-COS-CMC at 200 μg/mL, the inflammatory cytokines IL-6 and TNF-α level decreased by 70% and 80%, respectively. Tumor inhibition of DOX@MSNs-COS-CMC was 0.4 times higher than free DOX, alleviating cardiotoxicity and inflammation in the HeLa xenograft tumor model. Charge-reversible DOX@MSNs-COS-CMC could be a possible candidate for clinical therapy of cervical carcinoma.
Multidrug resistance (MDR) is frequently induced after long-term exposure to reduce the therapeutic effect of chemotherapeutic drugs, which is always associated with the overexpression of efflux proteins, such as P-glycoprotein (P-gp). Nano-delivery technology can be used as an efficient strategy to overcome tumor MDR. In this study, mesoporous silica nanoparticles (MSNs) were synthesized and linked with a disulfide bond and then coated with lipid bilayers. The functionalized shell/core delivery systems (HT-LMSNs-SS@DOX) were developed by loading drugs inside the pores of MSNs and conjugating with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and hyaluronic acid (HA) on the outer lipid surface. HT-LMSNs-SS and other carriers were characterized and assessed in terms of various characteristics. HT-LMSNs-SS@DOX exhibited a dual pH/reduction responsive drug release. The results also showed that modified LMSNs had good dispersity, biocompatibility, and drug-loading capacity. In vitro experiment results demonstrated that HT-LMSNs-SS were internalized by cells and mainly by clathrin-mediated endocytosis, with higher uptake efficiency than other carriers. Furthermore, HT-LMSNs-SS@DOX could effectively inhibit the expression of P-gp, increase the apoptosis ratios of MCF-7/ADR cells, and arrest cell cycle at the G0/G1 phase, with enhanced ability to induce excessive reactive oxygen species (ROS) production in cells. In tumor-bearing model mice, HT-LMSNs-SS@DOX similarly exhibited the highest inhibition activity against tumor growth, with good biosafety, among all of the treatment groups. Therefore, the nano-delivery systems developed herein achieve enhanced efficacy towards resistant tumors through targeted delivery and redox-responsive drug release, with broad application prospects.
Surface modification of mesoporous silica nanoparticles (MSNs) is a promising way to enhance therapeutic efficacy and minimize side effects of anticancer drugs. In this work, MSNs with reduced particle size and optimum pore diameter were obtained and catalyzed by ammonia/triethanolamine. In view of the negatively charged carboxymethyl chitosan (CMC) and positively charged chitosan oligosaccharide (CS), the pH-triggered charge-reversal CS/CMC bilayer was designed as a stimuli-responsive switch for MSNs via the protonation and deprotonation effect. The results showed that MSNs-CS/CMC were core-shell and mesoporous in structure. Surface charge conversion and pH dependence were clearly observed in the doxorubicin hydrochloride (DOX) delivery. The intracellular uptake indicated that DOX@MSNs-CS/CMC could be distributed in the cytoplasm of MCF-7 cells and exhibited lower toxicity, which would improve the stability and prolong the retention time compared to free DOX and unmodified DOX@MSNs at pH 7.4. Moreover, the cellular uptake and internalization of DOX@MSNs-CS/CMC were enhanced to promote drug delivery into the cell nucleus at pH 6.5. The biocompatible and surface-charge-reversible MSNs-CS/CMC have the potential to prolong the retention time in the bloodstream, facilitate the endosome escape, and enrich the targeted antitumor strategy, providing an alternative platform for efficient drug delivery in breast cancer therapy.
The applications of nanosized zirconia and composite powder become more and more significant with the development in the electronic and new material industries.In this paper,the traditional method was compared with hydrothermal method.The merit of the hydrothermal method,which has many routs including hydrothermal crystallization,hydrothermal precipitation,hydrothermal oxidation and microwave-hydrothermal process,was introduced.Various hydrothermal methods were summarized,which were adopted to obtain nanosized zirconia and composite powder.At last the difficulties for the hydrothermal method and the prespect in the future were proposed.
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