25 results about "Dihydroxyphenylalanine" patented technology

The invention belongs to the technical field of marine chemistry, relates to an anti-pollution type electrochemical sensor based on cyclopeptide as well as a preparation method and application of the anti-pollution type electrochemical sensor, and particularly discloses an environment-friendly all-solid-state calcium ion selective electrochemical sensor with anti-pollution capacity, which is used for monitoring calcium ions in ocean. The sensor adopts self-designed cyclic peptide as an antifouling layer, and the two ends of the newly designed cyclic peptide contain 3, 4-dihydroxyphenylalanine (DOPA) to form a stable annular structure, so that the stable annular structure can be firmly attached to the surface of an electrode. The abundant carbonyl groups and hydroxyl groups on the peptide chains of the cyclic peptides provide high hydrogen bond donor / acceptor capabilities, enabling them to form a hydrated layer on the interface that resists proteins or microorganisms. In addition, the anti-pollution capacity of the ion selective electrode modified by the cyclopeptide is remarkably improved, and the ion selective electrode shows good stability within 50 days. The method for introducing the anti-pollution cyclic peptide into the marine sensor is expected to improve the environmental compatibility and long-term stability of the marine sensor.

A Levodopa-selective sensor is provided. A continuous levodopa monitor is also provided. The levodopa sensor includes a sensor area having a working electrode with a levodopa-selective chemistry configured for at least partial implantation in a host. The sensor also includes at least one membrane adjacent the levodopa-selective chemistry. The at least one membrane includes an enzyme domain that at least one enzyme selected from a tyrosinase; a mutated tyrosinase with specificity towards I-3,4-dihydroxyphenylalanine; a dihydroxyphenylalanine 4,5-dioxygenase; a mutated dihydroxyphenylalanine 4,5-dioxygenase with specificity towards I-3,4-dihydroxyphenylalanine; and combinations thereof; a synthase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; a mutated synthase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; a 3,4-dihydroxyphenyl-acetaldehyde synthase; a mutated 3,4- dihydroxyphenyl-acetaldehyde synthase with specificity towards I-3,4-dihydroxyphenylalanine; a dioxygenase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; and a mutated dioxygenase enzyme with specificity towards I-3,4-dihydroxyphenylalanine.

A Levodopa-selective sensor is provided. A continuous levodopa monitor is also provided. The levodopa sensor includes a sensor area having a working electrode with a levodopa-selective chemistry configured for at least partial implantation in a host. The sensor also includes at least one membrane adjacent the levodopa-selective chemistry. The at least one membrane includes an enzyme domain that at least one enzyme selected from a tyrosinase; a mutated tyrosinase with specificity towards 1-3,4-dihydroxyphenylalanine; a dihydroxyphenylalanine 4,5-dioxygenase; a mutated dihydroxyphenylalanine 4,5-dioxygenase with specificity towards 1-3,4-dihydroxyphenylalanine; and combinations thereof; a synthase enzyme with specificity towards 1-3,4-dihydroxyphenylalanine; a mutated synthase enzyme with specificity towards 1-3,4-dihydroxyphenylalanine; a 3,4-dihydroxyphenyl-acetaldehyde synthase; a mutated 3,4-dihydroxyphenyl-acetaldehyde synthase with specificity towards 1-3,4-dihydroxyphenylalanine; a dioxygenase enzyme with specificity towards 1-3,4-dihydroxyphenylalanine; and a mutated dioxygenase enzyme with specificity towards 1-3,4-dihydroxyphenylalanine.

The application provides a kind of load exosome composite hydrogel and preparation method thereof, belong to biomaterial and drug delivery technical field;Its preparation method includes: modified chitosan;Modified hyaluronic acid;Preparation of biphasic calcium phosphate nanoparticles;Preparation of composite hydrogel.The application is through nucleophilic ring-opening reaction of 1,2-epoxy butane and the hydroxyl group of chitosan, form hydroxybutyl ether bond, give hydroxybutyl chitosan temperature sensitive characteristics, then, again, after activation 3,4-dihydroxyphenylalanine is condensed with hydroxybutyl chitosan, form amide bond, to graft 3,4-dihydroxyphenylalanine on hydroxybutyl chitosan, after modification of chitosan, 3,4-dihydroxyphenylalanine can form strong adhesion interface with cartilage, synovial membrane and other tissues through hydrogen bond, pi-pi stacking and metal coordination, thereby effectively prolonging the residence time of hydrogel in joint.

This invention relates to protein-based adhesives that are capable to adhere to a substrate in a dry, wet, moist, or an aqueous environment. Particularly, said adhesives comprise a crosslinking agent and an elastin-like polypeptide (ELP) that contain tyrosine, lysine, cysteine, dihydroxyphenylalanine (DOPA) or trihydroxyphenylalanine (TOPA) amino acid residue, or a combination thereof, on the polypeptide chain of said ELP. Among others, the adhesives disclosed herein may find broad applications in medical treatments and surgical operations. Compositions and methods of use are within the scope of this application.

This invention discloses a water-soluble melanin CEST contrast agent, its preparation method, and its application, relating to the field of magnetic resonance imaging contrast agent technology. This contrast agent, its preparation method, and its application aim to solve the technical problem that existing contrast agents containing paramagnetic metals can damage liver and kidney function. This water-soluble melanin CEST contrast agent comprises the following components by weight: 2-3 parts ammonia, 40 parts ethanol, 100 parts deionized water, and 0.5 parts reaction substrate. The chemical shift corresponding to this contrast agent preparation method is 4.0 ppm, exhibiting good adaptability to acidic environments and suitability for use in the tumor microenvironment. It is polymerized using dopamine hydrochloride or 3,4-dihydroxyphenylalanine, with inexpensive, simple, and readily available raw materials, simple synthesis, and easy large-scale preparation. It achieves tumor imaging without the need for paramagnetic metal ions, avoiding the damage to liver and kidney function caused by heavy metal ions.

The invention relates to the field of medicines, and provides a medicine-carrying balloon as well as a preparation method and application thereof. The medicine carrying balloon comprises a balloon and a medicine coating; the drug coating comprises a carrier and a drug, and the carrier comprises one or more of iopromide, butylated hydroxytoluene, phospholipid, cholesterol, dopamine, mussel mucin, 3, 4-dihydroxyphenylalanine, polydopamine, magnesium stearate, polylactic acid, polysorbate, polyethylene glycol, lac and lauryl sodium sulfate. The carrier serves as molecular glue, adheres to the medicine and the balloon and is combined with the medicine to form composite particles, and a firm medicine coating is formed. After transshipment at the target blood vessel, the'molecular glue 'exerts the adhesion effect, so that the composite particles are adhered to the target blood vessel for a long time, and the slow-release effect of the medicine is realized.

This invention relates to the field of anti-corrosion reagent technology, specifically disclosing a method for manufacturing a solid oxygen-removing, bactericidal, corrosion-inhibiting, and scale-inhibiting agent for seawater oil well pipelines. The agent comprises a three-layer core-shell structure: the core layer is composed of a copolymer hydrogel of 2-acrylamido-2-methylpropanesulfonic acid and N-vinylcaprolactam, loaded with sodium isoascorbate and a copper-L-histidine complex; the middle layer is composed of 3-aminophenylboronic acid-functionalized silica nanoparticles and catechol linked by dynamic borate ester bonds; and the shell layer is composed of a copolymer of 3,4-dihydroxyphenylalanine and 1H,1H,2H,2H-perfluorodecyl acrylate coating a corrosion-inhibiting and bactericidal complex. This invention overcomes the pH conflict between oxygen removers and corrosion inhibitors in traditional reagents through the synergistic effect of the core-shell structure and dynamic bonds, achieving integrated functions of oxygen removal, bactericidal action, corrosion inhibition, and scale inhibition. It effectively inhibits microbial corrosion, reduces the risk of scaling, extends the lifespan of seawater pipelines, and is suitable for complex marine conditions.

This invention relates to protein-based adhesives that are capable to adhere to a substrate in a dry, wet, moist, or an aqueous environment. Particularly, said adhesives comprise a crosslinking agent and an elastin-like polypeptide (ELP) that contain tyrosine, lysine, cysteine, dihydroxyphenylalanine (DOPA) or trihydroxyphenylalanine (TOPA) amino acid residue, or a combination thereof, on the polypeptide chain of said ELP. Among others, the adhesives disclosed herein may find broad applications in medical treatments and surgical operations. Compositions and methods of use are within the scope of this application.

The present invention discloses a recombinant human type 17 collagen mussel mucin polypeptide, its preparation method and use, and belongs to the field of genetic engineering technology. The present invention recombines a fragment of human type 17 collagen with the histidine and 3,4-dihydroxyphenylalanine-rich regions of mussel mucin, and the obtained recombinant protein has higher cell adhesion activity. The amino acid sequence of the polypeptide is shown in SEQ ID No.1 or SEQ ID No.2 or SEQ ID No.3 or SEQ ID No.4. The recombinant human type 17 collagen mussel mucin polypeptide of the present invention can be expressed at a high level in Escherichia coli as a host, its preparation method is simple, easy to scale up production, and can be widely used in industries such as medicine and cosmetics.

The application discloses a preparation method of light plastering gypsum and relates to the technical field of building materials. The preparation method of the light plastering gypsum comprises the following steps: after mirabilite gypsum is pretreated, the mirabilite gypsum is graded with desulfurization gypsum and phosphorite gypsum to obtain a gypsum base material; cellulose ether and starch ether are swelled together to form a cross-linked network colloidal, and polyether monomer, propylene-based monomer and an initiator are added to carry out graft copolymerization reaction to obtain a water-retaining and thickening component; a wall material is prepared from chitosan and sodium carboxymethyl cellulose, and 3,4-dihydroxyphenylalanine is coated to obtain a water-resistant and slow-release component; the gypsum base material is stirred and mixed with light aggregate and sepiolite fiber to obtain a primary mixture; and the primary mixture is stirred and mixed with the water-retaining and thickening component, the water-resistant and slow-release component and a water reducing agent to obtain the light plastering gypsum. The water-retaining property and the water resistance of the light plastering gypsum are greatly improved, the water range during construction is widened, and the construction difficulty is reduced.

The invention discloses a preparation method of a nano-copper-based conductive composite material. The invention relates to the technical field of conductive composite materials, which comprises the following preparation steps: step 1, preparation of a poly (catechol-polyamine)-copper precursor suspension: S11, preparing a mixed monomer solution which comprises a catechol-polyamine system, 3, 4-dihydroxyphenylalanine, gallic acid and Tween-80; and S12, adjusting the pH value of the mixed monomer solution to 8.5-9.0 by adopting a Tris-HCl buffer solution, and then sequentially adding copper sulfate, a composite oxidation system, dithiothreitol and phytic acid into the mixed monomer solution. According to the preparation method, a catechol-polyamine system and 3, 4-dihydroxyphenylalanine gallic acid are subjected to synergistic polymerization, a poly (catechol-polyamine) coating layer with a steric hindrance effect is formed on the surfaces of copper ions, meanwhile, tween-80 optimizes the hydrophilicity and hydrophobicity of the surfaces of the particles, dithiothreitol regulates and controls charge distribution on the surfaces of the particles, and the copper ions can be effectively dispersed in the particles. And particle agglomeration is inhibited from the source through multiple effects.

The invention discloses modified collagen, a precursor of the modified collagen, collagen gel containing the modified collagen, composite hydrogel containing the modified collagen and application of the modified collagen. Wherein the modified collagen has a structure as shown in the following formula: (3, 4-L-dihydroxyphenylalanine) n-collagen; wherein n is an integer greater than 1. The composite hydrogel prepared from the modified collagen and the biological bone meal has biocompatibility and a repairing effect.

The invention belongs to the technical field of pharmaceutical preparations, and particularly relates to a latamoxef sodium injection and a preparation method thereof. A modified hydroxypropyl methyl cellulose solution, a colloid solution and 3, 4-dihydroxyphenylalanine are mixed, the colloid solution is obtained through condensation reaction of histidine and ricinoleic acid under the emulsification effect of sucrose fatty acid ester, and the prepared stability-maintaining synergistic carrier matrix improves the acting effect of latamoxef sodium; the preparation method comprises the following steps: uniformly dispersing an anti-inflammatory, bacteriostatic and soothing solution into an emulsion solution formed by reaction of echinacea polysaccharide and octanoic acid, and freeze-drying to obtain the long-acting anti-inflammatory, bacteriostatic and soothing freeze-dried powder which can maintain the treatment effect for a long time; the latamoxef sodium nano-particles obtained after freezing nano spray drying are uniformly dispersed in a stability-maintaining basic solution, and the prepared latamoxef sodium nano-injection is high in stability, quick in drug effect, capable of playing a role for a long time and free of damage to an organism after being injected.

The invention relates to a surface chemical modification substrate and a preparation method thereof. According to the preparation method, surface modification is realized by utilizing the characteristic that a catechol modifier such as dihydroxyphenylalanine or dopamine can be subjected to auto-polymerization deposition on the surface of a resin substrate. After modification, new polar groups such as hydroxyl, carboxyl and amino can be generated on the surface of the substrate, and the polar groups can increase the chemical bonding effect between the substrate and copper and improve the interface bonding force.

This invention discloses a method for preparing a nano-copper-based conductive composite material, comprising the following preparation steps: Step 1, preparation of a poly(catechol-polyamine)-copper precursor suspension: S11, preparing a mixed monomer solution, wherein the mixed monomer solution contains a catechol-polyamine system, 3,4-dihydroxyphenylalanine, gallic acid, and Tween-80; S12, adjusting the pH of the mixed monomer solution to 8.5-9.0 using Tris-HCl buffer, and then sequentially adding copper sulfate, a composite oxidation system, dithiothreitol, and phytic acid. In this invention, through the synergistic polymerization of the catechol-polyamine system and 3,4-dihydroxyphenylalanine gallic acid, a poly(catechol-polyamine) coating layer with steric hindrance effect is formed on the surface of copper ions. Simultaneously, Tween-80 optimizes the hydrophilicity / hydrophobicity of the particle surface, and dithiothreitol regulates the charge distribution on the particle surface. These multiple effects fundamentally inhibit particle aggregation.

The invention provides exosome-loaded composite hydrogel and a preparation method thereof, and belongs to the technical field of biological materials and drug delivery. The preparation method comprises the following steps: modifying chitosan; modifying hyaluronic acid; preparing biphase calcium phosphate nanoparticles; and preparing the composite hydrogel. The preparation method comprises the following steps: carrying out a nucleophilic ring-opening reaction on 1, 2-epoxybutane and hydroxyl of chitosan to form a hydroxybutyl ether bond, endowing hydroxybutyl chitosan with a temperature-sensitive characteristic, carrying out a condensation reaction on hydroxybutyl chitosan and activated 3, 4-dihydroxyphenylalanine to form an amido bond, grafting 3, 4-dihydroxyphenylalanine onto hydroxybutyl chitosan, and carrying out a reaction on the 3, 4-dihydroxyphenylalanine and the hydroxybutyl chitosan to form the temperature-sensitive hydrogel. After chitosan is modified, 3, 4-dihydroxyphenylalanine can form a strong adhesion interface with tissues such as cartilage and synovial membranes through hydrogen bonds, pi-pi accumulation and metal coordination, so that the residence time of the hydrogel in joints is effectively prolonged.

The invention relates to the technical field of anti-corrosion reagents, and particularly discloses a manufacturing method of a solid deoxidizing and sterilizing corrosion and scale inhibitor for seawater oil well pipelines, the solid deoxidizing and sterilizing corrosion and scale inhibitor comprises a three-layer core-shell structure, the core layer is composed of copolymerized hydrogel of 2-acrylamido-2-methylpropanesulfonic acid and N-vinylcaprolactam, and the core layer is composed of copolymerized hydrogel of 2-acrylamido-2-methylpropanesulfonic acid and N-vinylcaprolactam; sodium erythorbate and a copper-L-histidine complex are loaded; the middle layer is formed by connecting 3-aminophenylboronic acid functionalized silicon dioxide nano-particles and catechol through dynamic boric acid ester bonds; the shell layer is formed by coating a corrosion inhibition and sterilization compound with a copolymer of 3, 4-dihydroxyphenylalanine and 1H, 1H, 2H, 2H-perfluorodecyl acrylate; through the synergistic effect of a core-shell structure and a dynamic bond, the pH conflict between a deoxidant and a corrosion inhibitor in a traditional reagent is broken through, the integrated functions of deoxygenation, sterilization, corrosion inhibition and scale inhibition are achieved, microbial corrosion can be effectively inhibited, the scaling risk is reduced, the service life of a seawater pipeline is prolonged, and the marine complex working condition is adapted.

The invention discloses an active peptide, the full-length sequence of the active peptide is (GPO) 5-K (R-Dopa) GD-[GHK (Cu < 2 + >)] 2-(TPP) 3-TAT-NH2, Dopa is 3, 4-dihydroxyphenylalanine, TPP is a triphenylphosphine cation, and GPO is Gly-Pro-Hyp. The invention further discloses an active peptide and stem cell exosome composition with a remarkable anti-aging effect. Through the synergistic effect of the active peptide and the stem cell exosome, the skin aging can be improved from the cellular level, and the active peptide composition has wide application prospects and is suitable for the fields of skin beautifying, anti-aging treatment and the like.

The present invention belongs to the field of marine chemical technology, and relates to an anti-pollution type electrochemical sensor based on cyclic peptides, its preparation method and application. Specifically, an environmentally friendly all-solid-state calcium ion selective electrochemical sensor with anti-pollution ability is disclosed for the monitoring of calcium ions in the ocean. The sensor uses a self-designed cyclic peptide as an anti-fouling layer. The newly designed cyclic peptide contains 3,4-dihydroxyphenylalanine (DOPA) at both ends, forming a stable ring structure, enabling it to firmly adhere to the electrode surface. The rich carbonyl and hydroxyl groups on the peptide chain of the cyclic peptide provide high hydrogen bond donor / acceptor ability, enabling them to form a hydrated layer that resists proteins or microorganisms at the interface. In addition, modifying the ion selective electrode with the cyclic peptide significantly improves its anti-pollution ability and exhibits good stability within 50 days. The method of introducing anti-pollution cyclic peptides into marine sensors in the present invention is expected to improve their environmental compatibility and long-term stability.

The invention discloses a bionic active peptide, a precursor of the bionic active peptide, modified bone meal containing the bionic active peptide, a bone regeneration repair material containing the bionic active peptide and application of the bionic active peptide. The bionic active peptide comprises n 3, 4-L-dihydroxyphenylalanine (DOPA), an E7 peptide and a self-assembled polypeptide which are sequentially connected from an N segment to a C end, wherein the amino acid sequence of the E7 peptide comprises a sequence as shown in SEQ ID NO: 1; and n is an integer between 2 and 8. The bone regeneration repair material prepared from the bionic active peptide has both mechanical property and repair property.

A method and use of an enantiomer 3,4-dihydroxyphenylalanine (DOPA) for enhancing plant attractiveness to beneficial insects by applying at least one time a composition having an effective amount of an enantiomer of DOPA selected from L-3,4-dihydroxyphenylalanine (L-DOPA) and D-3,4-dihydroxyphenylalanine (D-DOPA) or a mixture thereof to the leaves, stem and / or roots of the plant. The method provides an economical control of harmful insect pests and even allows preventive control prior to an infestation. As well as provide increases attraction of beneficial insects which in turn provide for an increased growth and propagation of the plant.

The present invention provides a method for preparing a flame-retardant PP material for a battery shell, comprising the following steps: S1. preparing titanium dioxide fiber filled with magnesium hydroxide; S2. adding the titanium dioxide fiber coated with magnesium hydroxide prepared in step S1 to dimethyl sulfoxide, stirring at a certain temperature, then adding sodium bisulfate, stirring and adding 3,4-dihydroxyphenylalanine, reacting under anaerobic conditions to obtain surface-modified fiber; S3. adding the surface-modified fiber prepared in step S2 to tetrahydrofuran containing phosphorus oxychloride, adding pyridine, and after ultrasonic reaction, dripping a tetrahydrofuran solution containing 4,4-diaminodiphenylmethane, and reacting to obtain P / N modified fiber; S4. melt blending PP, P / N modified fiber and antioxidant to obtain flame-retardant PP material. The present invention uses two inorganic flame retardants to compound in a specific manner, and surface-modify and add phosphorus and nitrogen, and apply them to PP materials to improve the flame retardant properties of battery shells.

To provide an inhibitor that can effectively inhibit diseases associated with microglial activation and that, owing to its comparative safety, allows regular oral administration.SOLUTION: The inhibitor for diseases associated with microglial activation according to the present invention is characterized by containing, as active ingredients, two or more aromatic amino acids selected from phenylglycine, phenylalanine, tyrosine, and dihydroxyphenylalanine, or salts thereof.SELECTED DRAWING: None