87 results about "Polysialic acid" patented technology

Methods of making ligand-decorated polymer conjugates of therapeutic glycoproteins are described. Improved targeting of glycoproteins to specific tissues is achieved by masking the natural carbohydrate and other surface determinants with high molecular weight polymers, such as, e.g., PEG, polysialic acid, etc., which in turn are decorated with target-specific ligands. In some embodiments, acid-labile linkages in such conjugates or rapidly degradable masking groups allow for the intracellular release of the polymer from the glycoprotein, for example, under conditions found in lysosomes.

The invention relates to sialic acid and an extraction method thereof and belongs to the technical field of sialic acid extraction. The method comprises the step of subjecting polysialic acid to a hydrolysis reaction for 10 to 40 minutes on a super-strength solid acid fixed bed. According to the sialic acid and the extraction method thereof, reaction time of the polysialic acid on the super-strength solid acid fixed bed is controlled to reduce degradation of the sialic acid, so that the purity of the sialic acid prepared from the polysialic acid through hydrolysis reaches 98% or more, and theyield of the sialic acid reaches 70% or more.

This invention discloses a method for decoloring polysialic acid hydrolysate. The method comprises: (1) performing aerobic fermentation on Escherichia coli strain to obtain fermented liquid containing polysialic acid, removing bacteria, precipitating with ethanol, and dissolving again in deionized water to prepare 2 wt.% polysialic acid solution; (2) hydrolyzing with an acid, neutralizing with an alkali, and centrifuging; (3) passing through an adsorption chromatographic column filled with attapulgite as the filler, eluting, collecting the eluant, and freeze-drying to obtain sialic acid product. Containing deep brown and red substances, the polysialic acid hydrolysate is treated by adsorption chromatography to obtain white powdery sialic acid product.

The invention relates to a fusion protein comprising a bifunctional sialytransferase and a poly-sialytransferase and methods to use the fusion proteins for production of poly-sialylated end products, e.g. oligosaccharides and glycoproteins.

The invention discloses a preparation method of polysialic acid-chitosan derivative hydrogel and belongs to the technical field of functional biological polymers. The polysialic acid-chitosan derivative hydrogel mainly comprises chitosan derivative and polysialic acid connected to the chitosan derivative and can form hydrogel and nano-particles. The polysialic acid-chitosan derivative hydrogel can be used in fields of drug embedding, medical coating, membrane materials and tissue engineering materials and has antibacterial properties, biocompatibility, low immunogenicity and biodegradability.

The invention discloses a separation and extraction method for N-acetylneuraminic acid. The separation and extraction method comprises the following steps: (1) carrying out acidolysis on a solution containing polysialic acid so as to obtain an acidolysis solution; (2) allowing the acidolysis solution obtained in the step (1) to pass through a first membrane to remove solid impurities so as to obtain a first permeate, allowing the first permeate to pass through a second membrane to remove macromolecular impurities so as to obtain a second permeate, allowing the second permeate to pass through athird membrane so as to remove monovalent salt, and collecting a trapped fluid; (3) adjusting the pH value of the trapped fluid to an N-acetylneuraminic acid isoelectric point, carrying out electrodialysis to remove multivalent salt, allowing a multivalent salt removed solution to pass through anion exchange resin for impurity washing and elution, collecting an effluent, and carrying out concentrating so as to obtain a concentrated solution; and (4) adjusting the pH value of the concentrated solution obtained in the step (3) to 1-3, adding a reverse solvent, carrying out cooling until a crystal is extracted, and carrying out centrifuging, washing and drying. The whole separation process is simple to operate; the purity of a crystal product is 99% or above; and the yield is greater than 90%.

The present invention provides analytical methods for detecting anti-polymer antibody in an individual. The methods involve contacting a sample from the individual with a water soluble polymer-modified carrier and detecting binding of antibody to the water soluble polymer on the water soluble polymer-modified carrier wherein binding is indicative of the presence of antibody to the water polymer-modified polypeptide. Antibody may be detected to water soluble polymers such as polyethylene glycol, polysialic acid, dextran, hydroxyalkyl starch, or hydroxyethyl starch. When antibody to the water soluble polymer polyethylene glycol is to be detected, the carrier is modified with a non-linear polyethylene glycol derivative.

The invention relates to a preparation method of N-acetylneuraminic acid. The main improvement of the preparation method is that a water solution of polysialic acid is subjected to microwave hydrolysis. Compared with an existing acid hydrolysis method, the method is easy to operate, low in cost, capable of achieving clean production, and free of environment pollution; the microwave hydrolysis ratereaches 90% or above, the time interval is 10-35 min, circulating hydrolysis is not needed, a sialic acid solution obtained after hydrolysis is few in by-product, subsequent purification treatment isfacilitated, and thus the yield and purification degree of a prepared finished product are high; and through the method, large-scale production is easy, and the investment return is high.

The invention belongs to the biological pharmacy field, and relates to a long-acting interferon, a preparation method therefor and applications thereof. The long-acting interferon comprises a polysialic-acid-modified interferon and a long-acting interferon recombination fusion protein. The polysialic acid is subjected to activation by utilization of sodium periodate. The activated polysialic acid reacts with an interferon to form a conjugate in the presence of sodium cyanoborohydride. The recombination fusion protein is composed of an N-end interferon and C-end naturally-existed hydrophilic polypeptides without repeated sequences. The fusion protein can be expressed in escherichia coli with high efficiency, and the preparation technology is simple and can be used for production preparation for large-scale medicine-level fusion proteins. The long-acting interferon can be used for treatment of virus infectious diseases of hepatitis virus, SARS, herpes simplex virus and the like, and is used for treatment of malignant tumors of malignant neuroglioma, lung cancer and the like and other cell proliferative diseases.

Disclosed are methods, compositions, devices, and kits for the isolation of brain-specific exosomes. Specifically, methods, compositions, devices, and kits comprising an isolated brain-specific extracellular vesicle or exosome joined to a first binding agent that is specific for tau, β-amyloid, S100 β, neuron-specific enolase, glycoprotein A2B5, CD133, NQ01, synaptophysin, neuronal nuclei, MAB1569, polysialic acid-neural cell adhesion molecule (PSA-NCAM), or neurogenic differentiation 1 (NeuroD or Beta2), or glycosylated or phosphorylated forms of these molecules, are provided.

The instant invention provides highly pure Polysialic acid and process for preparation thereof.

Novel bactericidal antibodies against Neisseria meningitidis serogroup B (“MenB”) are disclosed. The antibodies either do not cross-react or minimally cross-react with host tissue polysialic acid and hence pose minimal risk of autoimmune activity. The antibodies are used to identify molecular mimetics of unique epitopes found on MenB or E. coli K1. Examples of such peptide mimetics are described that elicit serum antibody capable of activating complement-mediated bacteriolysis of MenB. Vaccine compositions containing such mimetics can be used to prevent MenB or E. coli K1 disease without the risk of evoking autoantibody.