Nb2O5 nanowires in-situ grown on carbon fiber: A high-efficiency material for the photocatalytic reduction of Cr(VI).

Niobium oxide nanowire-deposited carbon fiber (CF) samples were prepared using a hydrothermal method with amorphous Nb2O5·nH2O as precursor. The physical properties of the samples were characterized by means of numerous techniques, including X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), UV-visible spectroscopy (UV-vis), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy. The efficiency for the removal of Cr(VI) was determined. Parameters such as pH value and initial Cr(VI) concentration could influence the Cr(VI) removal efficiency or adsorption capacity of the Nb2O5/carbon fiber sample obtained after hydrothermal treatment at 160°C for 14hr. The maximal Cr(VI) adsorption capacity of the Nb2O5 nanowire/CF sample was 115mg/g. This Nb2O5/CF sample also showed excellent photocatalytic activity and stability for the reduction of Cr(VI) under UV-light irradiation: the Cr(VI) removal efficiency reached 99.9% after UV-light irradiation for 1hr and there was no significant decrease in photocatalytic performance after the use of the sample for 10 repeated cycles. Such excellent Cr(VI) adsorption capacity and photocatalytic performance was related to its high surface area, abundant surface hydroxyl groups, and good UV-light absorption ability.

Injectable, anti-collapse, adhesive, plastic and bioactive bone graft substitute promotes bone regeneration by moderating oxidative stress in osteoporotic bone defect.

The treatment of osteoporotic bone defect remains a big clinical challenge because osteoporosis (OP) is associated with oxidative stress and high levels of reactive oxygen species (ROS), a condition detrimental for bone formation. Anti-oxidative nanomaterials such as selenium nanoparticles (SeNPs) have positive effect on osteogenesis owing to their pleiotropic pharmacological activity which can exert anti-oxidative stress functions to prevent bone loss and facilitate bone regeneration in OP. In the current study a strategy of one-pot method by introducing Poly (lactic acid-carbonate) (PDT) and ß-Tricalcium Phosphate (ß-TCP) with SeNPs, is developed to prepare an injectable, anti-collapse, shape-adaptive and adhesive bone graft substitute material (PDT-TCP-SE). The PDT-TCP-SE bone graft substitute exhibits sufficient adhesion in biological microenvironments and osteoinductive activity, angiogenic effect and anti-inflammatory as well as anti-oxidative effect in vitro and in vivo. Moreover, the PDT-TCP-SE can protect BMSCs from erastin-induced ferroptosis through the Sirt1/Nrf2/GPX4 antioxidant pathway, which, in together, demonstrated the bone graft substitute material as an emerging biomaterial with potential clinical application for the future treatment of osteoporotic bone defect. STATEMENT OF SIGNIFICANCE: Injectable, anti-collapse, adhesive, plastic and bioactive bone graft substitute was successfully synthesized. Incorporation of SeNPs with PDT into ß-TCP regenerated new bone in-situ by moderating oxidative stress in osteoporotic bone defects area. The PDT-TCP-SE bone graft substitute reduced high ROS levels in osteoporotic bone defect microenvironment. The bone graft substitute could also moderate oxidative stress and inhibit ferroptosis via Sirt1/Nrf2/GPX4 pathway in vitro. Moreover, the PDT-TCP-SE bone graft substitute could alleviate the inflammatory environment and promote bone regeneration in osteoporotic bone defect in vivo. This biomaterial has the advantages of simple synthesis, biocompatibility, anti-collapse, injectable, and regulation of oxidative stress level, which has potential application value in bone tissue engineering.

Enterovirus A71 utilizes host cell lipid ß-oxidation to promote its replication.

Enterovirus A71 (EV-A71) is a major pathogen that causes severe and fatal cases of hand-foot-and-mouth disease (HFMD), which is an infectious disease that endangers children's health. However, the pathogenic mechanisms underlying these severe clinical and pathological features remain incompletely understood. Metabolism and stress are known to play critical roles in multiple stages of the replication of viruses. Lipid metabolism and ER stress is an important characterization post viral infection. EV-A71 infection alters the perturbations of intracellular lipid homeostasis and induces ER stress. The characterizations induced by viral infections are essential for optimal virus replication and may be potential antiviral targets. In this study, we found that the addition of the chemical drug of ER stress, PKR IN, an inhibitor, or Tunicamycin, an activator, could significantly reduce viral replication with the decrease of lipid. The replication of viruses was reduced by Chemical reagent TOFA, an inhibitor of acetyl-CoA carboxylase (ACC) or C75, an inhibitor of fatty acid synthase (FASN), while enhanced by oleic acid (OA), which is a kind of exogenous supplement of triacylglycerol. The pharmacochemical reagent of carnitine palmitoyltransferase 1 (CPT1) called Etomoxir could knock down CPT1 to induce EV-A71 replication to decrease. This suggests that lipid, rather than ER stress, is the main factor affecting EV-A71 replication. In conclusion, this study revealed that it is the ß-oxidation of lipid that plays a core role, not ER stress, which is only a concomitant change without restrictive effect, on virus replication.

K. ZHENG ET AL.Gold-nanoparticle-based multistage drug delivery system for antitumor therapy.

Nanoparticles can promote the accumulation of drugs in tumors. However, they find limited clinical applications because they cannot easily penetrate the stroma of cancer tissues, and it is difficult to control drug release. We developed a multiresponse multistage drug-delivery nanogel with improved tumor permeability and responsiveness to the tumor microenvironment for the controlled delivery of anticancer agents. For this purpose, ∼100 nm multistage drug delivery nanogels with pH, redox, near-infrared stimulation, and enzyme responsiveness were grown in situ using 20 nm gold nanoparticles (AuNPs) via an emulsion-aiding crosslinking technique with cysteine crosslinker. An alginate cysteine AuNP (ACA) nanocarrier can efficiently load the cationic drug doxorubicin (DOX) to produce a multistage drug delivery nanocarrier (DOX@ACA). DOX@ACA can maintain the slow release of DOX and reduce its toxicity. In cancer tissues, the high pH and reductase microenvironment combined with the in vitro delivery of alginate and near-infrared light drove drug release. The developed nanoparticles effectively inhibited cancer cells, and in vivo evaluations showed that they effectively enhanced antitumor activity while having negligible in vivo toxicity to major organs.