Na metal anodes have attracted great interest because of their low electrochemical potential, high theoretical specific capacity, and natural abundance. However, nonuniform Na ion flux induced by an inhomogeneous solid electrolyte interphase (SEI) usually leads to the formation of mossy or dendritic Na, resulting in a low Coulombic efficiency (CE) and potential safety hazards. Herein, a well-designed artificial protective layer consisting of poly(vinylidene fluoride) (PVDF) and Sn nanoparticles was successfully constructed on a Cu current collector (PSN@Cu current collector) by a scalable and facile doctor blade coating technology. The flexible PVDF matrix in the protective layer can accommodate interface fluctuations, whereas the sodiophilic Sn nanoparticles can provide sufficient ionic conductivity for uniform deposition/stripping and a high mechanical modulus against potential dendrite growth. As a result, a high average CE of 99.73% can be achieved for 2800 h at 2 mA cm–2 with the PSN@Cu current collector. Furthermore, the PSN@Cu current collector has a stable cycling lifetime of 2300 h at 1 mAh cm–2, which is more than 10 times higher than that of bare Cu current collector (∼220 h). In addition, the unique structure and composition of the PSN-derived SEI are carefully investigated and can explain the much improved stability and electrochemical performance of Na metal anodes. This approach highlights the significance of a hybrid protective layer with synergistic properties and presents a new opportunity for stabilizing Na metal anodes.
siRNA is found to effectively knock down the target gene in cells, which is considered a promising strategy for gene therapy. However, the application of siRNA is limited due to its low efficiency of the cellular uptake. Tetrahedral framework nucleic acids (tFNAs) are synthesized by four single-stranded DNAs and show multiple biological functions in recent studies, especially suitable for drug delivery. More than 60% of malignant melanomas are associated with Braf gene mutation, an attractive therapeutic target for RNA interference. In this study, we modified anti-Braf siRNA (siBraf) with tFNAs to downregulate the target gene. Meanwhile, we directly incorporated AS1411 (a DNA aptamer) to our nanostructure, which assists tFNAs to improve the cellular uptake efficacy of siBraf significantly. The results indicated that tFNAs-AS1411-siBraf exhibited more potent activity to cleave Braf mRNA than free siBraf. This study may provide a new idea for the combination therapy of siRNA and aptamers via DNA nanomaterials to achieve gene silencing.
The cover image is based on the Original Article A minimally invasive method for titanium mesh fixation with resorbable sutures in guided bone regeneration: A retrospective study by Songhang Li DDS et al., https://doi.org/10.1111/cid.13147 . image
Aim: A comprehensive understanding of nanoparticle (NP)-protein interaction (protein corona formation) is required. So far, many factors influencing this interaction have been investigated, like size and ζ potential. However, NPs exposure concentration has always been ignored. Herein, we aim to disclose the correlation of NPs exposure concentration with protein adsorption. Materials & methods: Four polymeric NPs systems possessing similar sizes (230 ± 20 nm) but varied ζ potentials (−30 ∼ +40 mv) were prepared. Physicochemical properties and protein adsorption upon NP–protein interaction were characterized. Results: Protein adsorption capacity and adsorbed protein types were NPs concentration-dependent. Conclusion: Considering the critical impacts of protein adsorption on NPs delivery, our work could be an urgent warning about the possible risks of dosage adjustment of nanoformulations.
Some key issues in the design,fabrication and measurement of liquid crystal(LC) micolens array controlled electrically were discussed,which were:(1)The simulation of electric field distribution between electrodes of the lens is carried out,(2)the principle devices are fabricated through standard microelectronics technology,(3)optical interference performance is obtained by illumining the LC structure with Gaussian laser beam under the condition of changing the driving voltage of LC device.The LC microlens array acquired has some special features,such as simple fabrication technology,smart structure,low energy consumption,being easy to operate,being convenient to couple or integrate LC device with opto-electronic detectors,etc.We also analyze the possibility of improving and enhancing the opto-electronic performance of IR focal plane structure by utilizing the LC device.
Targeting drug delivery is an attractive research area, as it enables localized treatment, improves the efficacy of therapeutics and reduces systemic toxicity. Colon targeting delivery is particularly beneficial to the treatment of colon diseases, such as inflammatory bowel disease and colon cancer, due to the improved local drug concentrations. The traditional strategies for colon targeting delivery include time-dependent and pH-dependent technologies, etc. In recent years, nanotechnology has emerged as a novel and efficient tool for targeting drug delivery. After oral administration, nano-based formulations are able to protect drug from the harsh gastrointestinal environment and selectively increase the drug concentration at the disease site. Various orally administered drug-loaded nano-systems for colon targeting delivery have been well documented and shown great potentials in colon disease therapy.In this work, we aim to provide a comprehensive understanding of the recent progress in the area of colon targeting delivery in combination with introduction of the pathophysiological changes of diseased colon sites and the obstacles for drug delivery.
Ischemic stroke is a main cause of cognitive neurological deficits and disability worldwide due to a plethora of neuronal apoptosis. Unfortunately, numerous neuroprotectants for neurons have failed because of biological toxicity, severe side effects, and poor efficacy. Tetrahedral framework nucleic acids (tFNAs) possess excellent biocompatibility and various biological functions. Here, we tested the efficacy of a tFNA for providing neuroprotection against neuronal apoptosis in ischemic stroke. The tFNA prevented apoptosis of neurons (SHSY-5Y cells) caused by oxygen-glucose deprivation/reoxygenation through interfering with ischemia cascades (excitotoxicity and oxidative stress) in vitro. It effectively ameliorated the microenvironment of the ischemic hemisphere by upregulating expression of erythropoietin and inhibiting inflammation, which reversed neuronal loss, alleviated cell apoptosis, significantly shrank the infarction volume from 33.9% to 2.7%, and attenuated neurological deficits in transient middle cerebral artery occlusion (tMCAo) rat models in vivo. In addition, blocking the TLR2-MyD88-NF-κB signaling pathway is a potential mechanism of the neuroprotection by tFNA in ischemic stroke. These findings indicate that tFNA is a safe pleiotropic nanoneuroprotectant and a promising therapeutic strategy for ischemic stroke.
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