Hyperbranched Polymer Induced Antibacterial Tree-Like Nanofibrous Membrane for High Effective Air Filtration.

The air filtration materials with high efficiency, low resistance, and extra antibacterial property are crucial for personal health protection. Herein, a tree-like polyvinylidene fluoride (PVDF) nanofibrous membrane with hierarchical structure (trunk fiber of 447 nm, branched fiber of 24.7 nm) and high filtration capacity is demonstrated. Specifically, 2-hydroxypropyl trimethyl ammonium chloride terminated hyperbranched polymer (HBP-HTC) with near-spherical three-dimensional molecular structure and adjustable terminal positive groups is synthesized as an additive for PVDF electrospinning to enhance the jet splitting and promote the formation of branched ultrafine nanofibers, achieving a coverage rate of branched nanofibers over 90% that is superior than small molecular quaternary ammonium salts. The branched nanofibers network enhances mechanical properties and filtration efficiency (99.995% for 0.26 µm sodium chloride particles) of the PVDF/HBP-HTC membrane, which demonstrates reduced pressure drop (122.4 Pa) and a quality factor up to 0.083 Pa-1 on a 40 µm-thick sample. More importantly, the numerous quaternary ammonium salt groups of HBP-HTC deliver excellent antibacterial properties to the PVDF membranes. Bacterial inhibitive rate of 99.9% against both S. aureus and E. coli is demonstrated in a membrane with 3.0 wt% HBP-HTC. This work provides a new strategy for development of high-efficiency and antibacterial protection products.

Dual-Fuel Propelled Nanomotors with Two-Stage Permeation for Deep Bacterial Infection in the Treatment of Pulpitis.

Bacterial infection-induced inflammatory response could cause irreversible death of pulp tissue in the absence of timely and effective therapy. Given that, the narrow structure of root canal limits the therapeutic effects of passive diffusion-drugs, considerable attention has been drawn to the development of nanomotors, which have high tissue penetration abilities but generally face the problem of insufficient fuel concentration. To address this drawback, dual-fuel propelled nanomotors (DPNMs) by encapsulating L-arginine (L-Arg), calcium peroxide (CaO2 ) in metal-organic framework is developed. Under pathological environment, L-Arg could release nitric oxide (NO) by reacting with reactive oxygen species (ROS) to provide the driving force for movement. Remarkably, the depleted ROS could be supplemented through the reaction between CaO2 with acids abundant in the inflammatory microenvironment. Owing to high diffusivity, NO achieves further tissue penetration based on the first-stage propulsion of nanomotors, thereby removing deep-seated bacterial infection. Results indicate that the nanomotors effectively eliminate bacterial infection based on antibacterial activity of NO, thereby blocking inflammatory response and oxidative damage, forming reparative dentine layer to avoid further exposure and infection. Thus, this work provides a propagable strategy to overcome fuel shortage and facilitates the therapy of deep lesions.

Co-delivery of epirubicin and paclitaxel using an estrone-targeted PEGylated liposomal nanoparticle for breast cancer.

Breast cancer is one of the most frequent malignancies in the female population. Recently, the development of medical products has been advanced for this disease; however, patients still suffer from the failure of current treatments and new therapeutic strategies are urgently required. In this study, due to the overexpression of the estrogen receptor (ER) in breast cancer and the ability of ER to specifically bind to its ligand estrone (ES), an ES-targeted PEGylated epirubicin (EPI) and paclitaxel (PTX) co-loaded liposomal nanoparticle (NP) (termed as ES-SSL-EPI/PTX) was developed. Physicochemical studies demonstrated that the ES-SSL-EPI/PTX had a nanoscaled particle size (~120 nm) and a neutral zeta potential (~-5 mV) and presented favorable stability in physiological media. In vitro, the ES-SSL-EPI/PTX showed a significantly higher cellular uptake in human breast cancer MCF-7 cells mainly via the receptor-ligand mediated pathway resulting in effective cytotoxic activity. In vivo targeting study, the accumulation of targeted liposomes in tumor was significantly improved. The systemic circulation time and biodistribution in main organs of EPI and PTX delivered by ES-SSL-Liposomes were increased. Consequently, the ES-SSL-EPI/PTX significantly suppressed tumor growth in the MCF-7-derived tumor-bearing mouse model without inducing toxicity. These results suggested that the ES-SSL-EPI/PTX was a promising formulation for co-delivery of chemotherapeutics in the treatment of breast cancer.

Facile fabrication of shape-controlled CoxMnyOß nanocatalysts for benzene oxidation at low temperatures.

We report a new strategy for the design and construction of CoxMnyOß for C6H6 oxidation, a representative VOC. The nanostructures of CoxMnyOß can be tuned from nanowires to needles, hollow/hierarchical microspheres and nanocubes. Moreover, different nanostructures of CoxMnyOß show diverse textural/structural/surface properties, which in turn show strikingly different catalytic performances. Benefitting from its unique structural feature, nanocubic MnO2 exhibits a superior to considerably high activity for C6H6 oxidation at low temperatures.

Facile synthesis of Mn-Fe/CeO2 nanotubes by gradient electrospinning and their excellent catalytic performance for propane and methane oxidation.

Nanotubes have been the focus of vital efforts in the catalysis community because of their unique properties. However, owing to the limitations of synthetic methods, most multi-element oxides have rarely been fabricated. In this study, we design a gradient electrospinning method for the controllable synthesis of Mn-Fe/CeO2 nanocatalysts and their application in the combustion of propane and methane. The strategy is rational, and the nanostructure of Mn-Fe/CeO2 can be tuned by simply adjusting the weight ratio of polyvinyl pyrrolidone (PVP)/polyacrylonitrile (PAN) during the electrospinning process. Benefitting from its unique structural feature, propane and methane conversions in hollow tubular Mn-Fe/CeO2-P1 (mPVP : mPAN = 1 : 1) are more than 90% at 382 and 411 °C, respectively. The superior propane oxidation performance in Mn-Fe/CeO2-P1 is associated with its hollow tubular structure, high surface oxygen vacancies and excellent low-temperature reducibility.

Tris[2-(benzyl-imino-meth-yl)phenolato-κN,O]iron(III).

In the title compound, [Fe(C(14)H(12)NO)(3)], the Fe(III) atom has a slightly distorted octa-hedral geometry and is coordinated by three Schiff base ligands, viz. 2-(benzyl-imino-methyl)-phenolate. The crystal structure is stabilized by intra-molecular C-H⋯O and C-H⋯N hydrogen bonds.