Latest ArticlesPhotodynamic therapy (PDT) has been gaining popularity in both scientific research and clinic applications due to its non-invasiveness and spatiotemporal targeting properties. Nevertheless, the local hypoxic microenvironment in tumor tissue impedes PDT universality. To overcome this drawback, a 2-pyridone-bearing BODIPY photosensitizer was synthesized rationally and introduced to polyethyleneglycol-b-poly(aspartic acid) to form a photosensitizer-1O2 generation, storage/release agent dual-loading system (PEG-b-PAsp-BODIPY). The investigation of the PDT effect at different illumination conditions in vitro and in vivo revealed that the system tremendously inhibited tumor proliferation, indicating that this new PEG-b-PAsp-BODIPY could act as a potentially effective photo therapeutic system for cancer therapeutics.
Dendrite growth in lithium-ion batteries may bring thermal run-away especially at high current densities, which remains the major bottleneck to implement safe and fast charging for portable electronic devices or electronical vehicles. Designing dendrite inhibition separators with proper pore size is considered to be one of the most promising strategies to guarantee the battery safety. However, due to the impossible observation of lithium-ion distribution under separator by experiments, the underlying dendrite inhibition mechanism is still not fully understood. Here, we apply the phase-field model, which takes the separator phase into account to construct the electrochemical system total free energy, to study the ion re-distribution behavior of porous separator and understand the pore size inhibition effect on lithium dendrite. The numerical results indicate that separator with smaller pore size is beneficial to smoother electrodeposition, since the lithium-ion concentration on the electrode surface is more uniform under denser separator pores, when their sizes is larger than the critical nucleus. The proposed model could capture the physicochemical process of electrodeposition under multiphase structures, so it could also be used to explore dendrite growth under composite electrodes and composite solid electrolytes.
Metal-organic framework materials (MOFs), such as zeolitic imidazolate framework (ZIF), have been widely used in energy storage due to their advantages such as high structural stability, large specific surface, more active sites and skeleton structures. Herein, a novel two-dimensional (2D) CoCu-ZIF was synthesized by a facile solvothermal method. The as-prepared CoCu-ZIF nanosheets exhibit an ultrahigh reversible capacity of 2287.4 mAh/g and remains at 1172.1 mAh/g after 300 cycles at a current density of 100 mA/g, far better than that of the single Co-ZIF and Cu-ZIF. Additionally, the specific discharge capacity of CoCu-ZIF nanosheets can maintain at about 590 mAh/g after 1000 cycles at the current density of 2 A/g. Owing to the synergistic effect of two metals, function of nitrogen in the molecular and self-assembly 2D nanosheets, our research can provide strong support for the practical application of CoCu-ZIF materials in lithium ion batteries.
Bismuth sulfide (Bi2S3) is a promising anode material for high-performance potassium ion batteries due to its high theoretical capacity. However, the poor conductivity and substantial volume expansion hinder its practical application. We proposed an iodine-doped graphene encapsulated Bi2S3 nanorods composite (Bi2S3/IG) as an efficient anode for PIBs. The uniform-sized Bi2S3 nanorods evenly in-situ encapsulated in iodine-doped graphene framework, facilitating the electron transportation and structural stability. The potassium storage performance was evaluated in three electrolytes, with the best option of 5 mol/L KFSI in DME. The reversible capacity of representative Bi2S3/IG reached 453.5 mAh/g at 50 mA/g. Meanwhile, it could deliver an initial reversible capacity of 413.6 mAh/g at 100 mA/g, which maintained 256.9 mAh/g after 200 cycles. The proposed strategy contributes to improving potassium storage performance of metal sulfide anodes.
Exosomes are now raising focus as a prospective biomarker for cancer diagnostics and prognosis owing to its unique bio-origin and composition. Exosomes take part in cellular communication and receptor mediation and transfer their cargos (e.g., proteins, mRNA and DNA). Quantitative analysis of tumor-related nucleic acid mutations can be a potential method to cancer diagnosis and prognosis in early stages. Here we present an integrated microfluidic system for exosome on-chip isolation and lung cancer RNA analysis through droplet digital PCR (ddPCR). Gradient dilution experiments show great linearity over a large concentration range with R2 = 0.9998. Utilizing the system, four cell lines and two mutation targets were parallelly detected for mutation analysis. The experiments demonstrated mutation heterogeneity and the results were agree with cell researches. These results proved our integrated microfluidic system as a promising means for early cancer diagnosis and prognosis in the era of liquid biopsy.
Iron chalcogenides have attracted great interest as potential substitutes of nature enzymes in the colorimetric biological sensing due to their unique chemodynamic characteristics. Herein, we report the preparation of ultrathin FeS nanosheets (NSs) by a simple one-pot hydrothermal method and the prepared FeS NSs exhibit strong Fenton-reaction activity to catalyze hydrogen peroxide (H2O2) for generation of hydroxyl radical (•OH). Based on the chromogenic reaction of resultant •OH with 3, 3′, 5, 5′-tetramethylbenzidine (TMB), we develop colorimetric biosensors for highly sensitive detection of H2O2 and glutathione (GSH). The fabricated biosensors show wide linear ranges for the detection of H2O2 (5–150 µmol/L) and GSH (5–50 µmol/L). Their detection limits for H2O2 and GSH reach as low as 0.19 µmol/L and 0.14 µmol/L, respectively. The experimental results of sensing intracellular H2O2 and GSH demonstrate that this colorimetric method can realize the accurate detection of H2O2 and GSH in normal cells (L02 and 3T3) and cancer cells (MCF-7 and HeLa). Our results have demonstrated that the synthesized FeS NSs is a promising material to construct colorimetric biosensors for the sensitive detection of H2O2 and GSH, holding great promising for medical diagnosis in cancer therapy.
Tuning white-light emission via free radicals is still a challenge in molecular-based functional materials. Herein, a new photoactive Zn2+ oxalate-based chain containing a polypyridine ligand was designed and synthesized with remarkably bifunctional photochromism and photo-actuated greenish white-light emission after UV, sunlight or Xe lamp light irradiation at room temperature. The photo-actuated coloration process was induced by the photogeneration of stable radicals originated from intermolecular electron transfers from oxalate components to the protonated polypyridine units, as demonstrated by UV–vis, IR, electron spin resonance and X-ray photoelectron spectra and magnetic measurements. Importantly, the on/off greenish white light emission (WLE) could be reversibly switched by generation and elimination of radicals via light irradiation and heat treatment, providing a feasible strategy for designing photoswitchable light emission diodes materials.
Transition metal selenides attract significant attention as advanced anode materials for sodium-ion batteries (SIBs) in recent years due to their appropriate working potential and high theoretic capacity. However, the poor structural stability and rate capability limit their further practical applications. Herein, zeolite imidazole framework-8/zeolite imidazole framework-67 is used as a template to prepare Co0.85Se and ZnSe nanoparticles embed in N-doped carbon matrix successfully, and then coated a carbon layer (ZCS@NC@C) by in-situ polymerization. One side, the N-doped carbon matrix with rich pore structure not only shorten the diffusion path of Na+ and improve the conductivity of the electrode, but also prevent structural collapse and agglomeration of active particles during the sodium insertion/extraction process. On the other side, the carbon shell preparation by coating can form a protective layer to buffer the volumetric stress generated in the electrochemical process and further improve the electrical conductivity. As a result, the as-prepared ZCS@NC@C anode material exhibits an excellent electrochemical performance for SIBs. This investigation provides a promising approach to optimize the electrochemical performance of SIBs by incorporating active metal compounds into conductive carbons to form multidimensional structure.
Gestational diabetes mellitus (GDM), a frequently-occurring disease during pregnancy, may cause some adverse healthy outcome of both mother and offspring. However, the knowledge about metabolite alterations during the pathogenesis and development process is limited. Here, a large longitudinal non-targeted metabolomics study of 195 pregnant women (64 women with subsequently developed GDM and 131 healthy controls) was conducted. Each participant provided urine samples at three timepoints during early, middle and late pregnancy, respectively. The metabolic profiles of 585 urine samples (195 × 3) were measured by using ultra-high performance liquid chromatography coupled with Orbitrap high-resolution mass spectrometry. Among the 56 identified metabolites, the levels of eight metabolites increased and three ones decreased in the first trimester, the concentration of one metabolite increased and those of 20 decreased in the second trimester, as well as the levels of five metabolites increased and two decreased in the third trimester. After false discovery rate correction, the levels of valine and 5-acetamidovalerate in GDM group significantly increased in the first trimester, the levels of 1-methylguanine and 1, 3-dihydro-(2H)-indol-2-one significantly decreased in the second trimester and three metabolites (threonine, OH-octanedioyl-carnitine and pimelylcarnitine) increased and N-acetyltryptophan decreased in the third trimester, respectively. Six metabolites, such as pantothenic acid and threonine, had significant interaction effects between gestational stage (different trimester) and group (GDM or control). The differential metabolites were involved in "tryptophan metabolism", "purine metabolism", "valine, leucine and isoleucine degradation" and other pathways. The findings may provide insights into further pathogenesis study of GDM.
The temperature monitoring of treated cancer cells is critical in photothermal therapy. Current methods of detecting intracellular temperatures have low accuracy and poor spatial resolution, which limits their application to photothermal therapy. Herein, a strategy for targeted recognition and selective capture of MCF-7 breast cancer cells based on fluorescent polymer poly(N-isopropylacrylamide-benzoxadiazole-2-vinyl-4,4-dimethyl azlactone, PNMV) and modified gold nanobipyramids (AuNBPs-PNMV) was developed for temperature sensing during photothermal therapy. A mucin-1 protein aptamer (Apt) was applied to selectively target mucin-1 protein overexpressed on the surfaces of the MCF-7 cells, which can reduce interference by affinity interaction between the Apt and proteins. During photothermal therapy, the significant AuNBPs photothermal effect increases the fluorescence intensity of PNMV with temperature. Irradiation of MCF-7 cells cultured with AuNBPs-PNMV@Apt by an 808 nm laser increases the temperature of the system, while the cells can be inactivated because of the remarkable AuNBPs-PNMV@Apt photothermal effect. The results indicate that variation in the fluorescence of AuNBPs-PNMV@Apt can be applied as thermometers to monitor the intracellular effect of photothermal therapy.