PVA/WO3-x/Ag2WO4 Hydrogel for Enhanced Photocatalytic Disinfection and Accelerated Wound Healing.

Bacterial wound infections are one of the growing health and safety threats to the public. In this study, WO3-x/Ag2WO4 photocatalysts were synthesized, and heterogeneous structures were constructed for non-antibiotic bactericidal use. Due to the heterostructure constructed with Ag2WO4, the photogenerated carrier separation efficiency and reactive oxygen generation capacity of WO3-x were improved, which in turn improved the inactivation rate of bacteria. Also, this photocatalyst was loaded into PVA hydrogel for photodynamic treatment of bacterial wound infections. This hydrogel dressing was demonstrated to have good biosafety by in vitro cytotoxicity tests and to have a wound healing-promoting effect by in vivo wound healing experiments. This light-driven antimicrobial hydrogel has the potential ability to treat bacterial wound infections.

Enhanced virulence of genetically engineered Autographa californica nucleopolyhedrovirus owing to accelerated viral DNA replication aided by inserted ascovirus genes.

Genetic engineering technology is an ideal method to improve insecticidal efficiency by combining the advantages of different pathogenic microorganisms. Thus, six ascovirus genes were introduced into the genomic DNA of Autographa californica nucleopolyhedrovirus (AcMNPV) to possibly transfer the intrinsically valuable insecticidal properties from ascovirus to baculovirus. The viral budded virus (BV) production and viral DNA replication ability of AcMNPV-111 and AcMNPV-165 were significantly stronger than that of AcMNPV-Egfp (used as the wild-type virus in this study), whereas AcMNPV-33 had reduced ones. AcMNPV-111 and AcMNPV-165 also exhibited excellent insecticidal efficiency in the in vivo bioassays: AcMNPV-111 showed a 24.1% decrease in the LT50 value and AcMNPV-165 exhibited a 56.3% decrease in the LD50 value compared with AcMNPV-Egfp against the 3rd instar of Spodoptera exigua larvae, respectively. Furthermore, the size of the occlusion bodies (OBs) of AcMNPV-33, AcMNPV-111, and AcMNPV-165 were significantly increased compared to that of AcMNPV-Egfp. AcMNPV-111 and AcMNPV-165 had stable virulence against the 2nd to 4th instars tested larvae and higher OB yield than AcMNPV-Egfp in the 3rd and 4th instar larvae. Correlation and regression analyses indicated that it is better to use 5 OBs/larva virus to infect the 2nd instar larvae to produce AcMNPV-111 and 50 OBs/larva virus to infect the 3rd instar larvae to produce AcMNPV-165. The results of this study obtained recombinant viruses with enhanced virulence and exhibited a diversity of ascovirus gene function based on the baculovirus platform, which provided a novel strategy for the improvement of baculovirus as a biological insecticide.

Chitosan Sponge/Cu-WO3-x Composite for Photodynamic Therapy of Wound Infection.

One of the potential treatments for bacterial wound infections is photodynamic therapy. WO3-x semiconductor materials can generate reactive oxygen species when exposed to light, which can inactivate bacteria. In this work, we improved their photocatalytic performance by doping WO3-x with Cu. The wound dressing was prepared by loading Cu-WO3-x into a highly biocompatible chitosan sponge. The composite sponge dressing showed significant inactivation of Escherichia coli and Staphylococcus aureus, and in vitro toxicity assays on L929 cells demonstrated the biosafety of the dressing. Through in vivo wound healing trials, composite sponge dressings have been shown to accelerate wound healing, and this composite chitosan sponge can be possibly used for photodynamic therapy of bacterial wound infections.

Malignant Peripheral Nerve Sheath Tumor in the Nasal Cavity of a Neonate: A Case Report.

Malignant peripheral nerve sheath tumor (MPNST) is a rare tumor that can develop on the lining of nerves and within the network of nerve fibers in different organs, and it is commonly found in the head and neck, limbs, and trunk. These tumors can occur in patients of any age. They most commonly occur in adults aged 20 to 50 years; however, fewer cases of this tumor in children have been reported. To date, no neonatal case of MPNST in the nasal cavity has been reported. Here, we report the case of a 4-day-old female newborn who presented with a nasal mass that re-enlarged after surgery and was diagnosed as MPNST of the nasal cavity on the basis of pathological results. This is the first report of MPNST in the nasal cavity of a neonate. Differential diagnosis and treatment of nasal masses have been proposed in the related literature.

Photoactive Nanomaterials for Wireless Neural Biomimetics, Stimulation, and Regeneration.

Nanomaterials at the neural interface can provide the bridge between bioelectronic devices and native neural tissues and achieve bidirectional transmission of signals with our brain. Photoactive nanomaterials, such as inorganic and polymeric nanoparticles, nanotubes, nanowires, nanorods, nanosheets or related, are being explored to mimic, modulate, control, or even substitute the functions of neural cells or tissues. They show great promise in next generation technologies for the neural interface with excellent spatial and temporal accuracy. In this review, we highlight the discovery and understanding of these nanomaterials in precise control of an individual neuron, biomimetic retinal prosthetics for vision restoration, repair or regeneration of central or peripheral neural tissues, and wireless deep brain stimulation for treatment of movement or mental disorders. The most intriguing feature is that the photoactive materials fit within a minimally invasive and wireless strategy to trigger the flux of neurologically active molecules and thus influences the cell membrane potential or key signaling molecule related to gene expression. In particular, we focus on worthy pathways of photosignal transduction at the nanomaterial-neural interface and the behavior of the biological system. Finally, we describe the challenges on how to design photoactive nanomaterials specific to neurological disorders. There are also some open issues such as long-term interface stability and signal transduction efficiency to further explore for clinical practice.

The Effect of STAT3 Signal Pathway Activation on Retinopathy of Prematurity.

Objective: To investigate the mechanism of activation of the signal transducer and activator of transcription 3 (STAT3) signal pathway in the process of retinopathy of prematurity (ROP). Methods: Sixty newborn Sprague-Dawley (SD) rats were randomly separated into the hyperoxia and air control groups (n = 30/in each group). The serum hepcidin level on 21 d was measured using the enzyme-linked immunosorbent assay (ELISA). The expression of HAMP and STAT3 protein in the liver was determined using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Retinal neovasculature was evaluated by hematoxylin and eosin (HE) stain and fluorescein lectin. The retinal endothelial cells were treated with 250 µmol/L cobalt chloride for 72 h and added S3I-201. The STAT3 level was determined by western blotting. Results: The expression of STAT3 protein increased significantly after hyperoxia stimulation. The expression of HAMP mRNA in the hyperoxia group was significantly higher than that of the control group. The proliferation of retinal cells was inhibited, and the expression of STAT3 was increased. No significant difference was noted in vascular endothelial growth factor (VEGF) mRNA. The expression of STAT3 and VEGF mRNA was significantly reduced. Conclusion: The activation of the STAT3 signal pathway increased hepcidin expression, contributing to the pathogenesis of ROP. S3I-201 inhibited the expression of STAT3 and VEGF mRNA levels. This information provides potential novel therapeutic approach to the prevention and treatment of ROP.

Effect of Probenecid on Endothelial Cell Growth Rate and Retinal Angiogenesis in an Oxygen-Induced Retinopathy Model.

Objectives: Probenecid is an anion transport inhibitor, which, according to the connectivity map (CMap; a biological application database), interferes with hypoxia-induced gene expression changes in retinal vascular endothelial cells (ECs). Here, we investigated the influence of probenecid on retinal EC cytotoxicity and retinal neovascularization in a murine oxygen-induced retinopathy (OIR) model. Methods: The retinal EC growth rate in the presence of hypoxia-mimicking concentrations of cobalt chloride (CoCl2) was determined using the thiazolyl blue tetrazolium bromide (MTT) assay and proliferating cell nuclear antigen (PCNA) expression. In OIR rats, probenecid was administered by intraperitoneal injection (i.p.) from postnatal day (P) 1 to P7. The concentrations of vitreous humor vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1α, and placental growth factor (PlGF) were determined by using the ELISA kit at P21. The amount of newly formed vascular lumen was evaluated by histopathological examination. Retinopathy and neovascularization were assessed by scoring isolectin B4 fluorescein-stained retinal flat mounts. Western blots for liver tissue HIF-1α and hepcidin (HAMP) were performed. Results: In vitro, probenecid led to the recession of the hypoxia-induced EC growth rate. In vivo, compared to the OIR retina, the upregulation of VEGF, HIF-1α, and PlGF in phase II retinopathy of prematurity (ROP) was inhibited by probenecid administration. Moreover, probenecid ameliorated neovascularization and resulted in significantly reduced relative leakage fluorescence signal intensity in fluorescein-stained retinal flat mounts (p < 0.05). Probenecid alleviated the liver overactivation of HAMP and downregulation of HIF-1α in OIR rats. Conclusions: This is the first demonstration that implies that probenecid might be a protective compound against retinal angiogenesis in OIR. These changes are accompanied with decreased hyperoxia-mediated hepcidin overproduction. Although the relevance of the results to ROP needs further research, these findings may help establish potential pharmacological targets based on the CMap database.

Conductive Hydrogel for a Photothermal-Responsive Stretchable Artificial Nerve and Coalescing with a Damaged Peripheral Nerve.

Modern development of flexible electronics has made use of bioelectronic materials as artificial tissue in vivo. As hydrogels are more similar to nerve tissue, functional hydrogels have become a promising candidate for bioelectronics. Meanwhile, interfacing functional hydrogels and living tissues is at the forefront of bioelectronics. The peripheral nerve injury often leads to paralysis, chronic pain, neurologic disorders, and even disability, because it has affected the bioelectrical signal transmission between the brain and the rest of body. Here, a kind of light-stimuli-responsive and stretchable conducting polymer hydrogel (CPH) is developed to explore artificial nerve. The conductivity of CPH can be enhanced when illuminated by near-infrared light, which can promote the conduction of the bioelectrical signal. When CPH is mechanically elongated, it still has high durability of conductivity and, thus, can accommodate unexpected strain of nerve tissues in motion. Thereby, CPH can better serve as an implant of the serious peripheral nerve injury in vivo, especially in the case that the length of the missing nerve exceeds 10 mm.

Nickel-Catalyzed Desymmetrizing Cross-Electrophile Coupling of Cyclic Meso-Anhydrides.

A Ni-catalyzed desymmetrizing cross-electrophile coupling of cyclic meso-anhydrides with aryl triflates has been successfully demonstrated. This is the only example using cyclic meso-anhydrides in cross-electrophile coupling reactions. A diverse array of valuable γ-keto acid building blocks can be generated under these conditions with excellent functional group tolerance and stereochemical fidelity.