1194 results about "Surface charges" patented technology

Non-adhesive particles as large as 110 nm can diffuse rapidly in the brain ECS, if coated with hydrophilic coatings such as PEG coatings and preferably having neutral surface charge. The ability to achieve brain penetration with larger particles will significantly improve drug and gene delivery within the CNS since larger particles offer higher drug payload, improved drug loading efficiency, and significantly longer drug release durations.

Hydrogel devices for surgical implantation to replace damaged cartilage in a mammalian joint (such as a knee, hip, shoulder, etc.) are disclosed, with one or more of the following enhancements: (1) articulating surfaces that have been given negative surface charge densities that emulate natural cartilage and that interact with positively charged components of synovial fluid; (2) anchoring systems with affixed pegs that will lock into accommodating receptacles, which will be anchored into hard bone before the implant is inserted into a joint; (3) a three-dimensional reinforcing mesh made of strong but flexible fibers, embedded within at least a portion of the hydrogel.

Engineered microparticles, libraries of microparticles, and methods relating thereto. The microparticles are distinguishable based on differences in dielectric response to an applied electric field. In different embodiments, the dielectric differences may be engineered through, but not limited to, dielectrically dispersive materials, surface charge, and / or fluorescence. Gangliosides may be incorporated with the microparticles to control aggregation. Vesicles including erythrocyte ghosts may be used as a basis for microparticles. The microparticles may utilize a biotin streptavidin system for surface functionalization.

The invention discloses a composition of chitosan-shelled nanoparticles and methods of manufacturing. The chitosan-shelled nanoparticles are characterized with a positive surface charge and enhanced epithelial ermeability for oral drug delivery.

Edge termination for silicon carbide devices has a plurality of concentric floating guard rings in a silicon carbide layer that are adjacent and spaced apart from a silicon carbide-based semiconductor junction. An insulating layer, such as an oxide, is provided on the floating guard rings and a silicon carbide surface charge compensation region is provided between the floating guard rings and is adjacent the insulating layer. Methods of fabricating such edge termination are also provided.

Methods of improving a performance parameter of a microbial fuel cell are provided according to embodiments of the present invention which include heating an electrode and exposing the heated electrode to ammonia gas to produce a treated electrode characterized by an increased positive surface charge on the electrode surface. Improved performance parameters include increased maximum power density, increased coulombic efficiency, increased volumetric power density and decreased microbial fuel cell operation time to achieve maximum power density

Therapeutic compositions of microspheres for application to wounds and / or lesions for accelerating wound healing and muscle regeneration. The microspheres are made up of non-biodegradable material having a substantial surface charge. The therapeutic composition further includes a pharmaceutically acceptable carrier in which the microspheres are insoluble and a container for holding the composition. The therapeutic composition further contains pharmacologic agents or biologics that accelerate the wound healing process.

Methods for the preparation of a lipid-nucleic acid composition are provided. According to the methods, a mixture of lipids containing a protonatable or deprotonatable lipid, for example an amino lipid and a lipid such as a PEG- or Polyamide oligomer-modified lipid is combined with a buffered aqueous solution of a charged therapeutic agent, for example polyanionic nucleic acids, to produce particles in which the therapeutic agent is encapsulated in a lipid vesicle. Surface charges on the lipid particles are at least partially neutralized to provide surface-neutralized lipid-encapsulated compositions of the therapeutic agents. The method permits the preparation of compositions with high ratios of therapeutic agent to lipid and with encapsulation efficiencies in excess of 50%.

The present inventors discovered that the half-life in blood of an IgG antibody which is a polypeptide comprising an FcRn-binding domain can be controlled by controlling the surface charge through modification of residues exposed on the surface among residues in the variable regions of the IgG antibody. Antibodies whose half-life in blood had been controlled by the methods of the present invention were confirmed to actually retain the original activity. The methods of the present invention are widely applicable to polypeptides comprising an FcRn-binding domain, such as IgG antibodies, which are recycled via the FcRn salvage pathway regardless of the type of target antigen.

The invention relates to an electrospinning nano-fiber electret filtering material and its preparation method. The high-efficiency and low-resistsance nano-fiber electret filtering material having no interfibrous adhesion and having a fluffy three-dimensional netted intercommunication structure is prepared through controlling the component and the temperatures of a polymer solution in an electrospinning process and carrying out one-step forming in the nano-fiber forming rapid cooling process, wherein the gram weight of the above nanofiber layer is 0.01-70g / m<2>, and the porosity is not less than 80%. The surface electrostatic potential of the nano-fiber electret filtering material is 800-6000V, and the surface charges have lasting storage stability, the hydrophobic angle is greater than 150DEG, the filtering efficiency of the material to particles of 0.006-1[mu]m can reach above 99.999%, the piezoresistance is less than 20Pa, and the dust containing capacity is 300-3600g / m<2>. The preparation method is simple, and the filtering material has wide application prospects in the fields of individual protection mouth mask filtration, indoor air purification and filtration, and high efficiency / ultrahigh efficiency air filtration.

The invention discloses a chewable composition for oral delivery of bioactive agents having nanoparticles that are composed of chitosan, poly-glutamic acid, and at least one protein drug or bioactive agent characterized with a positive surface charge and their enhanced permeability for paracellular protein drug and bioactive agent delivery.

A DNA microarray system whereby measurement can be performed at a low running cost, a low price and yet a high accuracy. A nucleic a cid probe 3is immobilized on the surface of a gate insulator of an electric field effect transistor and then hybridized with a target gene on the surface of the insulator. A change in the surface electric charge density thus arising is detected by using the electric effect.

The invention relates to an active carbon serving as a catalyst carrier and a treatment method and application thereof. After being subjected to heating and dipping treatment in hydrogen peroxide, the specific surface area of the active carbon is 900 to 1,300m<2> / g and the mesopore distribution ratio is 20 to 30 percent. The treatment method has short treatment time and high speed, is convenient to operate and is easy to realize. The micropore size distribution and the micropore surface charge reorganization of the treated active carbon adsorptive catalyst are well improved. The active carbon treated by the method is suitable for serving as the carrier of a synthesis catalyst for the industrial production of vinyl acetate.

Devices, coatings, and methods therefore comprise a medical device for delivering nanoparticles of an active agent to a treatment site. A coating on the medical device comprises active agent nanoparticles, which delivers coating to the treatment site and releases active agent nanoparticles into the treatment site over at least one day. A coating may comprise a polymer, a surfactant, and the nanoparticles. The coating may be prepared by forming a nanoemulsion. A coating may comprise encapsulated active agent nanoparticles which comprise active agent nanoparticles encapsulated in a polymer. The coating may have a positive surface charge. The coating may deliver active agent nanoparticles into the treatment site over at least about one day. The coating may be formed of a surfactant and nanoparticles mixture. The active agent nanoparticles may be deposited on the medical device using electrostatic capture.

Nanoparticles formed by emulsion of one or more core polymers, one or more surface altering materials, and one or more low molecular weight emulsifiers have been developed. The particles are made by dissolving the one or more core polymers in an organic solvent, adding the solution of the one or more core polymers to an aqueous solution or suspension of the emulsifier to form an emulsion, and then adding the emulsion to a second solution or suspension of the emulsifier to effect formation of the nanoparticles. In the preferred embodiment, the molecular weight of the emulsifiers is less than 1500, 1300, 1200, 1000, 800, 600, or 500 amu. Preferred emulsifiers include cholic acid sodium salt, dioctyl sulfosuccinate sodium, hexadecyltrimethyl ammonium bromide, saponin, TWEEN® 20, TWEEN® 80, and sugar esters. The surface altering materials are present in an amount effective to make the surface charge of the particles neutral or essentially neutral when the one or more emulsifiers are charged. The emulsifiers have an emulsification capacity of at least about 50%, preferably at least 55, 60, 65, 70, 75, 80, 85, 90, or 95%.

Fluorescent microspheres for the measurement of blood flow are provided. The microspheres are substantially uniform in diameter and have a hydrophobic surface, which allows them to circulate more freely throughout bloodstream, while reducing immunogenicity, particle aggregation and bioaccumulation. The hydrophobic surface on each microsphere is generally comprised of polymeric material having a limited surface charge.

The present invention relates to methods for conditioning a surface before application of powder coating, methods for improving powder coating transfer to a surface, methods for reducing defects on powder painted surfaces, methods for providing homogenous surface charge on a surface, methods for increasing adhesion of powder paint to a surface, and surface conditioners for use in such methods.

The present invention relates to liquid sustained release suspension dosage forms comprising ionized forms of water-soluble drugs. In particular, the invention encompasses a liquid form controlled release drug composition comprising a dispersed phase comprising an ion-exchange matrix drug complex comprising a pharmaceutically acceptable ion-exchange matrix and a water-soluble electrolytic drug associated with the ion-exchange matrix, wherein the surface charge of the ion-exchange matrix is opposite that of the electrolytic drug and a dispersion medium substantially free of diffusible counterions, further comprising a polyelectrolyte having the same charge as the electrolytic drug. The invention also provides methods for preparing such compositions and methods of treatment.

The invention relates to a preparation method of a nano particle carbon nanotube compound catalyst. The carbon nanotube with electric charges on surface is obtained from the materials which can generate non-covalent action with the carbon nanotube. Then nano particle with opposite electric charges on surface to that of the non-covalent modified carbon nanotube is added and completely mixed, and excess nano particle is removed to finally obtain the nano particle carbon nanotube catalyst compound. A plurality of nano particle carbon nanotube catalyst compounds can be prepared by the invention, all of which represent very good catalytic activities. The invention adopts the method of non-covalent modified carbon nanotube to obtain carbon nanotube with perfect surface. Meanwhile, the invention provides the nano particle, in particular, the morphology controllable nano particle on the load of carbon nanotube with an effective way by utilizing the electrostatic interaction of carbon nanotube and namo particle, thus extending the applications of morphology controllable nano particle in catalytic field.

In one embodiment, a semiconductor device is formed having sub-surface charge compensation regions in proximity to channel regions of the device. The charge compensation trenches comprise at least two opposite conductivity type semiconductor layers. A channel connecting region electrically couples the channel region to one of the at least two opposite conductivity type semiconductor layers.

The invention relates to a novel amino acid silicon polymer with good adhesion to the keratin layer of the skin, a method of preparing the amino acid silicon polymer, a cosmetic particles surface-treated with the amino acid silicon polymer, and a color cosmetic composition including the cosmetic particles. According to the present invention, the particles surface-treated up to 3% to the maximum with the amino acid silicon polymer prepared by reacting an amino acid and a functional silicon polymer in the manner of organic synthesis have water resistance and usability peculiar to silicon-treated pigments and take positive surface charges, thereby offering good adhesion to the skin and durability. Due to these characteristics, the cosmetic containing the surface-treated particles of the present invention is superior in the cosmetic effect to that containing the conventional surface-treated particles.

An inexpensive DNA chip / DNA microarray system capable of highly accurate measurement with low running cost. A DNA probe 8 is immobilized on a floating electrode 7 connected to a gate electrode 5 of a field effect transistor. Hybridization with a target gene is carried out on the surface of the floating electrode, when a change in surface charge density is detected using a field effect.

A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.

Methods for preparing particles and related compositions are provided. In some embodiments, the particles include at least one polynucleotide (e.g., mRNA), and in certain embodiments, the particles may include at least one ionizable molecule (e.g., a lipid). A method for preparing a suspension including the particles may comprise one or more filtration steps. In some such embodiments, prior to or during filtration, one or more properties of the particles (e.g., surface charge) and / or one or more properties of the suspension (e.g., pH) may be altered. In some embodiments, altering one or more properties of the particles and / or suspension may improve yield, improve a characteristic of the resulting composition, and / or prevent or reduce certain problems, such as fouling during the filtration process.

A plurality of primary beams are formed from a single electron source, the surface charge of a sample is controlled by at least one primary beam, and at the same time, the inspection of the sample is conducted using a primary beam other than this. Also, for an exposure area of the primary beam for surface charge control and an exposure area of the primary beam for the inspection, the surface electric field strength is set individually. Also, the current of the primary beam for surface charge control and the interval between the primary beam for surface charge control and the primary beam for inspection are controlled.

This invention provides methods for producing a polymer particle which contains unusually high negative charges on the surface of the particle. Preferably, the polymer is pharmaceutically acceptable. The negative charges can be conferred by chemical groups such as carboxyl, sulfonate, nitrate, fluorate, chloride, iodide, persulfate, and many others, with carboxyl group being preferred. The invention also provides polymer particle produced by the methods of the invention.

The invention discloses the nanoparticles composed of chitosan, poly-γ-glutamic acid, and at least one bioactive agent characterized with a positive surface charge and their enhanced permeability for paracellular drug delivery.

The invention discloses a surface charge measuring system with an external motion control mechanism and a measuring method. The surface charge measuring system and the measuring method aim to solve the problem that under a high-voltage SF6 environment, the surface charge of a component such as an insulator in a complex shape is difficult to measure. The surface charge measuring system mainly comprises a main shell, a side shell, an upper parallel-plate electrode, a lower parallel-plate electrode, an electrostatic measuring probe and a high-speed high-voltage electrostatic potential meter. According to a surface charge measuring device provided in the surface charge measuring system and the measurement method, the operation that one of the electrostatic measuring probe and the insulator rotates and the other one of the electrostatic measuring probe and the insulator moves horizontally can be achieved simultaneously by using equipment such as a multifunctional motion controller and a stepping motor, and it is ensured that the electrostatic measuring probe can scan and measure all parts of the surface of the insulator to be measured step by step.