Covalent organic frameworks (COFs) are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability, good crystallinity, a large specific surface area, and controllable structures. COFs are widely used in the fields of adsorption and separation, catalysis, photovoltaics, and drug-delivery. The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods. In which, the types of linkage are closely related to the stability and performance of COFs. In this review, nitrogen-containing linkage-bonds (NCLBs) in COFs are divided into N-containing double bonds, N-containing conjugated rings and N-containing unconjugated rings. The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized. Moreover, the structural design, theoretical prediction and machinable application of COFs are prospected

For realizing the goals of “carbon peak” and “carbon neutrality”, lithium-ion batteries (LIB) with LiFePO₄ as the cathode material have been widely applied. However, this has also led to a large number of spent lithium-ion batteries, and the safe disposal of spent lithium-ion batteries is an urgent issue. Currently, the main reason for the capacity decay of LiFePO₄ materials is the Li deficiency and the formation of the Fe³⁺ phase. In order to address this issue, we performed high-temperature calcination of the discarded lithium iron phosphate cathode material in a carbon dioxide environment to reduce or partially remove the carbon coating on its surface. Subsequently, mechanical grinding was conducted to ensure thorough mixing of the lithium source with the discarded lithium iron phosphate. The reaction between CO₂ and the carbon coating produced a reducing atmosphere, reducing Fe³⁺ to Fe²⁺ and thereby reducing the content of Fe³⁺. The Fe³⁺ content in the repaired LiFePO₄ material is reduced. The crystal structure of spent LiFePO₄ cathode materials was repaired more completely compare with the traditional pretreatment method, and the repaired LiFePO₄ material shows good electrochemical performance and cycling stability. Under 0.1 C conditions, the initial capacity can reach 149.1 mAh/g. It can be reintroduced for commercial use.

Due to their high specificity and affinity towards various targets, along with other unique advantages such as stability and low cost, aptamers are widely applied in analytical techniques. A typical aptamer-based electrochemical biosensor is composed of a aptamer as the biological recognition element and transducer converting the biologic interaction into electrical signals for the quantitative measurement of targets. Improvement of the sensitivity of a biosensor is significantly important in order to achieve the detection of biomolecules with low abundance, and different amplification strategies have been explored. The strategies either employ nanomaterials such as gold nanoparticles to construct electrodes which can transfer the biological reactions more efficiently, or attempt to obtain enhanced signal through multi-labeled carriers or utilize enzyme mimics to catalyze redox cycling. This review discusses recent advances in signal amplification methods and their applications. Critical assessment of each method is also considered.

The discrimination against nutritional fat emulsion injections was considered by imaging tools, which aims to elucidate the in vivo behaviors of nanoemulsions. In this study, 20% nutritional fat emulsion injections were selected from different company including original and generic products. Meanwhile, a water quenching fluorescent probe (P2) was used to label them by an incubation method. The fluorescent intensity analysis of blood-borne fluorescence reveals rapid clearance of nanoemulsion in all groups, which shows 'L'-type blood kinetic profiles. However, these kinetic parameters do not have significant difference. Following intravenous administration, the nanoemulsions in all groups concomitantly accumulated in organs of reticulo-endothelial system (RES), such as liver and spleen, and were cleared from body circulation mostly after 12 h. AUC_(0-t) of organs from different groups showed dissimilar results in some organs. These intuitional results are of significance in understanding the in vivo behaviors of nanoemulsions, which can provide a new way to discriminate against nutritional fat emulsions.

The demand for injectable dermal filler has undergone significant growth with the rapid development of the beauty industry. Poly(lactic acid) (PLA) as a benefit of excellent biocompatibility and long-term promotion of collagen regeneration has been favored as a commonly used filler. However, the effects of chirality and particle size of PLA on the efficacy of dermal filler have not been studied. In this study, we prepared three kinds of microspheres (MSs) consisting of poly(D-lactic acid) (PDLA MS), poly(L-lactic acid) (PLLA MS), or meso-PLA (PDLLA MS) at 5, 10 and 20 μm to reveal the different biological functions as dermal filler. Following intradermal injection into guinea pig, it was found that PLLA MS induced the slightest inflammation, and the level of pro-inflammatory cytokine IL-1β induced by PLLA MS is only 0.3 or 0.7-fold of that induced by PDLA or PDLLA MS, respectively. More importantly, PLLA MS significantly stimulated the regeneration of collagen, which was 1.4 or 1.1 times higher than those stimulated by PDLA MS or PDLLA MS, respectively. The size of PLA MSs did not affect the levels of inflammation and collagen regeneration. The results confirmed the superiority of PLLA as a dermal filler.

Small interfering RNA (siRNA), a promising revolutionary therapy, faces delivery obstacles due to its poor targeting, strong charge negativity and macromolecular nature. Clinical-approved siRNAs can now only be delivered to the liver mediated by the chemically conjugated N-acetylgalactosamine (GalNAc) ligand, the conjugate can be effectively uptaken into cells through interaction with asialoglycoprotein receptor (ASGPR) highly expressed on liver hepatocytes. To further explore an efficient non-hepatic targeted delivery strategy, in this study, we designed a delivery system that chemically conjugated p53 siRNA to renal tubular cell-targeting peptides for targeting the kidney, which was suitable for industrial transformation. Results showed that peptide-siRNA conjugate could specifically enter renal tubular epithelial cells and silence target genes. In cisplatin-induced acute kidney injury (AKI) mice, peptide-siRNA conjugate blocked the p53-mediated apoptotic pathway and alleviated renal damage. The innovative proposed system to conjugate kidney-targeting peptides with siRNA achieved the efficient kidney-targeted delivery of siRNA and provided a prospective choice for treating AKI.

Tyrosinase (TYR) is an important polyphenolic oxidase enzyme and usually regards as a biomarker of melanoma cancer. Highly effective tracking TYR activity in vivo will help to study the mechanism of TYR in living organisms and forecasts related diseases. In this study, we present a novel TYR-activatable fluorescent probe (CHMC-DOPA) for tracking TYR activity in vitro and in vivo. CHMC-DOPA is constructed by incorporating dopamine (DOPA) moiety into a fluorescent chloro-hydroxyl-merocyanine (CHMC) scaffold. Upon exposure to TYR, the dopamine unit in CHMC-DOPA is oxidized to a dopaquinone derivative, and an intramolecular photo-induced electron transfer (PET) process between CHMC fluorophore and o-dopaquinone will take place, the fluorescence of CHMC-DOPA is quenched rapidly. Therefore, the evaluation of TYR activity is established in terms of the relationship between fluorescence quenching efficiency and TYR activity. In our experiments, CHMC-DOPA shows various advantages, such as fast response (8 min), low concentration of TYR activation (0.5 U/mL), good water-solubility, as well as the lowest detection limit (0.003 U/mL) compared with previously reported works. Furthermore, CHMC-DOPA also exhibits excellent cell membrane permeability and low cytotoxicity, which is successfully used to monitor endogenous TYR activity in living cancer cells and zebrafish models. CHMC-DOPA performs well, and we anticipate that this newly designed novel platform will provide an alternative for high effective monitoring TYR activity in biosystems.

Sodium metal has been widely studied in the field of batteries due to its high theoretical specific capacity (~1,166 mAh/g), low redox potential (-2.71 V compared to standard hydrogen electrode), and low-cost advantages. However, problems such as unstable solid electrolyte interface (SEI), uncontrolled dendrite growth, and side reactions between solid-liquid interfaces have hindered the practical application of sodium metal anodes (SMAs). Currently, lots of strategies have been developed to achieve stabilized sodium metal anodes. Among these strategies, modified metal current collectors (MCCs) stand out due to their unique role in accommodating volumetric fluctuations with superior structure, lowering the energy barrier for sodium nucleation, and providing guided uniform sodium deposition. In this review, we first introduced three common metal-based current collectors applied to SMAs. Then, we summarized strategies to improve sodium deposition behavior by optimally engineering the surface of MCCs, including surface loading, surface structural design, and surface engineering for functional modification. We have followed the latest research progress and summarized surface optimization cases on different MCCs and their applications in battery systems.

Achieving high energy densities for all-solid-state lithium batteries is restricted by the poor high voltage stability of solid electrolytes. Herein, F-doping strategy is successfully employed on Li₃InCl₆ to obtain enhanced voltage stability and electrode compatability towards bare LiNi_0.7Mn_0.2Co_0.1O₂ at high voltages. The optimized Li₃InCl_5.5F_0.5 electrolyte exhibits a decreased conductivity of 1.00 mS/cm, a wider voltage window, and improved electrochemical performance in solid-state batteries when cycled at upper cut-off voltages of 4.5 and 4.8 V (vs. Li⁺/Li⁰). The generation of more stable LiInF₄ phase in the cathode mixture of Li₃InCl_5.5F_0.5-based battery ensures superior electrochemical performances compared to the Li₃InCl₆-based battery. The former battery exhibits a higher discharge capacity of 218.9 mAh/g and coulombic efficiency of 86.7% for the first cycle, and retains 80.0% of its original value after 100 cycles when cycled in the range of 3.0–4.5 V (vs. Li⁺/Li⁰). In contrast, the Li₃InCl₆-based battery exhibits lower capacities and faster degradation under the same conditions due to the formation of InCl₃ phase with poor electrochemical stability. This work facilitates the advancement of high energy density solid-state battery technologies by utilizing high-voltage cathodes.

Solid-state batteries (SSBs) with thermal stable solid-state electrolytes (SSEs) show intrinsic capacity and great potential in energy density improvement. SSEs play critical role, however, their low ionic conductivity at room temperature and high brittleness hinder their further development. In this paper, polypropylene (PP)-polyvinylidene fluoride (PVDF)-Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP)-Lithium bis(trifluoromethane sulphonyl)imide (LiTFSI) multi-layered composite solid electrolyte (CSE) is prepared by a simple separator coating strategy. The incorporation of LATP nanoparticle fillers and high concentration LiTFSI not only reduces the crystallinity of PVDF, but also forms a solvation structure, which contributes to high ionic conductivity in a wide temperature. In addition, using a PP separator as the supporting film, the mechanical strength of the electrolyte was improved and the growth of lithium dendrites are effectively inhibited. The results show that the CSE prepared in this paper has a high ionic conductivity of 6.38×10^–4 S/cm at room temperature and significantly improves the mechanical properties, the tensile strength reaches 11.02 MPa. The cycle time of Li/Li symmetric cell assembled by CSE at room temperature can exceed 800 h. The Li/LFP full cell can cycle over 800 cycles and the specific capacity of Li/LFP full cell can still reach 120 mAh/g after 800 cycles at 2 C. This CSE has good cycle stability and excellent mechanical strength at room temperature, which provides an effective method to improve the performance of solid electrolytes under moderate condition.