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Polymeric nanoparticles have been widely investigated as insulin delivery systems for oral administration. However, the toxic nature of many artificial polymers hampers their effective application, creating a demand for the further exploration of alternative natural polymers. In addition, ethnobotanical research has reported that over 800 plant species have a hypoglycemic function, some of which are polymers. For the advantages of both areas to be combined, the aim of this work was to choose an organic hypoglycemic polymer and prepare it into an insulin carrier to build a dual-functional oral insulin delivery system. We found that the insulin loading rate, release mode, thermostability, and both in vitro and in vivo absorption and efficacy varied with the different modifications of polygalacturonic acid (PGLA) nanoparticulate backbones. By in vivo pharmaceutical testing and constantly monitoring the symptoms of type 1 diabetic (T1D) rats, we ascertained the hypoglycemic function of the nanoparticles and showed that overall diabetic symptoms were ameliorated after the long-term daily administration of nanoparticles with no significant damage to organ structure or cell viability. [ABSTRACT FROM AUTHOR]

A thorough understanding of the antimicrobial mechanisms of graphene materials (GMs) is critical to the manipulation of highly efficient antimicrobial nanomaterials for future biomedical applications. Here we review the most recent studies of GM-mediated antimicrobial properties. This review covers the physicochemical properties of GMs, experimental surroundings, and selected microorganisms as well as the interaction between GMs and selected microorganisms to explore controversial antimicrobial activities. Finally, we rationally analyze the strengths and weaknesses of the proposed mechanisms and provide new insights into the remaining challenges and perspectives for future studies. [ABSTRACT FROM AUTHOR]

Controlled manipulation of individual micro- and nanoscaleobjectsrequires the use of trapping forces that can be focused and translatedwith high spatial and time resolution. We report a new strategy thatuses the flow of mobile microvortices to trap and manipulate singleobjects in fluid with essentially no restrictions on their materialproperties. Fluidic trapping forces are generated toward the centerof microvortices formed by magnetic microactuators, that is, rotatingnanowire or self-assembled microbeads, actuated by a weak rotatingmagnetic field (|B|< 5 mT). We demonstrate precisemanipulation of single microspheres and microorganisms near a solidsurface in water. [ABSTRACT FROM AUTHOR]

In this work, a facile surfactant-directed process is developed for controlling the morphology of ZnO with distinctive shapes ranging from mushrooms, bihemispheres, dumbbells, bilayer hexagonal disks and prisms to flower-like nanosheet aggregations. The flower-like aggregated nanosheets were formed by oriented attached 4 nm nanoparticles. The hexagonal disks and prisms 1−2 μm in diameter and 50 nm to approximately 4 μm in thickness (or length) were enclosed by {101̅0} facets. The growth mechanism of these bilayer hexagonal structures was studied by microscopy and spectroscopy. In addition, by replacing the conventional oil−water system, the simple alcohol−water surfactant system employed here provides a more environmentally benign and biosafe approach. [ABSTRACT FROM AUTHOR]

Capacitance−voltage characteristics of individual germanium nanowire field effect transistors were directly measured and used to assess carrier mobility in nanowires for the first time, thereby removing uncertainties in calculated mobility due to device geometries, surface and interface states, and gate dielectric constants and thicknesses. Direct experimental evidence showed that surround-gated nanowire transistors exhibit higher capacitance and better electrostatic gate control than top-gated devices, and are the most promising structure for future high performance nanoelectronics. [ABSTRACT FROM AUTHOR]

Core-shell germanium nanowires (GeNW) are formed with a single-crystalline Ge core and concentric shells of nitride and silicon passivation layer by chemical vapor deposition (CVD), an Al2O3gate dielectric layer by atomic layer deposition (ALD), and an Al metal surround-gate (SG) shell by isotropic magnetron sputter deposition. Surround-gate nanowire field-effect transistors (FETs) are then constructed using a novel self-aligned fabrication approach. Individual SG GeNW FETs show improved switching over GeNW FETs with planar gate stacks owing to improved electrostatics. FET devices comprised of multiple quasi-aligned SG GeNWs in parallel are also constructed. Collectively, tens of SG GeNWs afford on-currents exceeding 0.1 mA at low source-drain bias voltages. The self-aligned surround-gate scheme can be generalized to various semiconductor nanowire materials. [ABSTRACT FROM AUTHOR]

The fabrication of nanohelices by the scrolling of strained bilayers is investigated. It is shown that structure design is dominated by edge effects rather than bulk crystal properties such as the Young's modulus when the dimensions of the structures are reduced below 400 nm. SiGe/Si/Cr, SiGe/Si, and Si/Cr helical nanobelts are used as test structures. Dimensions of the belt width are reduced from 1.30 μm to 300 nm, and parameters controlling helicity angle, chirality, diameter, and pitch of the nanohelices are investigated. An anomalous scrolling direction deviating from the preferred 〈100〉 scrolling direction has been found for small structures. Making use of the anomalous scrolling, it is possible to fabricate three-dimensional helices with helicity angles less than 45°, which is advantageous for micro- and nanoelectromechanical systems. [ABSTRACT FROM AUTHOR]