254 results about "Oxidised cellulose" patented technology

Hemostatic agents and devices are made from oxidized cellulose fiber, the oxidized cellulose having a carboxylation content increased by the action of nitrogen dioxide on virgin cellulose fiber. A composition may be incorporated into the oxidized cellulose fiber to cause a pharmacological effect on a wound to which the hemostatic agents and devices are applied. When applied, the oxidized cellulose fiber causes blood emanating from the wound to clot. The oxidized cellulose fiber can either be resorbed into the wound or removed from the wound after healing. A hemostatic bandage includes a pad of unwoven oxidized cellulose fibers mounted on a substrate. Methods of arresting a flow of blood emanating from a wound using such devices are also disclosed. Methods of fabricating oxidized cellulose are also disclosed.

The present invention is directed to a hemostatic wound dressing that utilizes a fibrous, fabric substrate made from carboxylic-oxidized cellulose and containing a first surface and a second surface opposing the first surface, the fabric having flexibility, strength and porosity effective for use as a hemostat; and further having a porous, polymeric matrix substantially homogeneously distributed on the first and second surfaces and through the fabric, the porous, polymeric matrix being made of a biocompatible, water-soluble or water-swellable cellulose polymer, wherein prior to distribution of the polymeric matrix on and through the fabric, the fabric contains about 3 percent by weight or more of water-soluble oligosaccharides.

A new cellulose excipient, OCCAE, suitable for use as a binder, filler, and/or disintegrant in the development of solid dosage forms and as a bodying agent or a drug carrier in the preparation of topical formulations is described. The cellulose excipient is formed by reacting an oxidized cellulose ester with an alcohol in the presence of a catalyst. The invention also describes the formation of controlled release microspheres using OCCAE and/or oxidized cellulose esters that may be used to control the release of drug in a patient over a time period of several hours to several days.

This invention provides cellulose ester interpolymers, and methods of oxidizing cellulose interpolymers and cellulose ester interpolymers. The invention also provides routes to access carboxylated cellulose ester derivatives with high acid numbers wherein the carboxyl group is attached directly to the cellulose backbone by a carbon-carbon bond. Through functionalization of an intermediate aldehyde, the corresponding cationic or zwitterionic cellulose ester derivatives can also be accessed. The interpolymers of the present invention have a number of end-use applications, for example, as binder resins in various types of coating compositions and as drug delivery agents.

The invention discloses a preparation method of modified cellulose adsorbents. The preparation method comprises the following steps: (1) activating cellulose in alkaline aqueous solution to obtain activated cellulose; (2) reacting the activated cellulose with epoxy chloropropane to obtain epoxy cellulose; (3) reacting the epoxy cellulose with an oxidizing agent to obtain epoxy dialdehyde oxidized cellulose; (4) reacting cyclodextrin with epoxy dialdehyde oxidized cellulose to obtain cyclodextrin grafted modified cellulose; and (5) reacting the cyclodextrin grafted modified cellulose with amino-terminated hyperbranched polymer to obtain the modified cellulose adsorbents. The raw material source is wide, the price is low, and the environment-friendly effect is achieved; the preparation method is simple, the reaction condition is mild, the equipment requirement is low and scale production is facilitated; and the prepared adsorbent has stable performance and broad-spectrum adsorption capacity for heavy metal ions, dyes and other organic matters and is environment-friendly, the cellulose additional value is remarkably promoted, and good economic and social benefits are achieved.

The invention discloses a cellulose fiber-supported nano silver antibacterial material and a preparation method thereof. The preparation method comprises the steps of: conducting chemical pretreatment on cellulose fibers, then conducting TEMPO (2, 2, 6, 6-tetramethylpiperidine-1-oxyl) selective oxidization on the cellulose fibers, and finally on the premise that not any reducing agent is added, enabling the oxidized cellulose fibers to react with silver nitrate in silver nitrate water solution through a short-time microwave heating method to prepare the cellulose fiber-supported nano silver antibacterial material with small-diameter and even-structure nano silver particles. By adopting the preparation method, on the premise that not any reducing agent is added, in-situ reduction and growth of nano silver on carboxylated cellulose fiber supporters are realized. The prepared cellulose fiber-supported nano silver antibacterial material has the advantages of small nano grain size and even size, and can be widely applied to the fields of antibacterial operation clothes, wound dressing, drug controlled release, textile coating and the like.

A medically acceptable formulation comprising a diisocyanate terminated macromer or mixture thereof, and an oxidized cellulose.

A method of preparing a cellulose-based difunctional adsorbent is disclosed. The method includes (1) a step of preliminary treatment, namely a step of removing impurities of a cellulose-based raw material, then boiling the raw material in a sodium hydroxide solution, washing the raw material with water, drying the raw material and cutting the raw material into pieces; (2) a step of pretreatment, namely a step of subjecting the raw material to ultrasonic wave-alkali solution-ultrasonic wave combined treatment, and (3) a step of chemical modification, namely a step of subjecting the raw material to selective oxidation treatment, then adding the oxidized cellulose into a reaction medium, adding an anhydride into the reaction medium, stirring, refluxing and reacting the mixture, performing filtration after the reaction is finished, washing a product, drying the product, reacting the product with a polyamine compound, performing filtration, washing an obtained product with water until neutrality, and freeze-drying the product to obtain the cellulose-based difunctional adsorbent. The adsorbent prepared by the method is high in safety stability, has good adsorption functions for anion pollutants and cation pollutants, and can be used for cleaning treatment of heavy metal ion waste water and dye waste water. The source of the cellulose-based raw material used for preparing the adsorbent is wide, and the cost is low. Operation is convenient when the adsorbent is used for waste water treatment.

Provided is a method which is capable of producing a cellulose nanofiber dispersion liquid that has a low viscosity and excellent fluidity even at a high concentration, while exhibiting excellent transparency. In a method for producing cellulose nanofibers, wherein a cellulosic starting material is oxidized in water using an oxidant in the presence of an N-oxyl compound and a compound that is selected from the group consisting of a bromide, an iodide and a mixture thereof and the thus obtained oxidized cellulose is defibrated and dispersed, pulp which is obtained by carrying out kraft cooking after a hydrolysis process is used as the cellulosic starting material.

The invention relates to a preparation method for aldehyde group or carboxyl group-containing oxidized cellulose nanofibers by adopting an electrostatic spinning method. The preparation method comprises the following steps of: oxidizing cellulose and performing electrostatic spinning on oxidized cellulose solution, wherein aldehyde groups and carboxyl groups are generated in the oxidized cellulose; 0.1 to 30 percent oxidized cellulose solution is obtained by dissolving the oxidized cellulose in a dissolution system; and oxidized cellulose non-woven fabric with the average thickness of 0.01 mu m to 5 mm, the porosity of 60 to 90 percent, the tensile strength of 1 to 20 MPa and the elastic elongation percentage of 1 to 15 percent; and the fibers have the diameters of between 50 nm and 3 mu m.

The invention provides a preparation method for an oxidized regenerated cellulose hemostatic material with a surface nanostructure. In order to solve problems of small specific surface area, water insolubility, single hemostatic effect mechanism and low hemostatic speed of the traditional oxidized cellulose hemostatic material, the invention provides the preparation method for the oxidized regenerated cellulose hemostatic material with the surface nanostructure. The method comprises the following steps of: (1) preparing a collagen aqueous solution; (2) preparing a viscose fiber gauze; (3) preparing oxidized viscose staple fiber and oxidized viscose fiber gauze; (4) preparing an oxidized regenerated cellulose sodium solution or an oxidized regenerated cellulose potassium solution; (5) preparing an oxidized regenerated cellulose gauze; and (6) after collagen particles are sprayed, freezing and drying the oxidized regenerated cellulose gauze, so as to finish the preparation of the oxidized regenerated cellulose hemostatic material with the surface nanostructure. The preparation method for the oxidized regenerated cellulose hemostatic material with the surface nanostructure, provided by the invention, is applied to the preparation field of the oxidized regenerated cellulose hemostatic materials.

The invention relates to a method for preparing carboxycellulose by using hydrogen peroxide. The method comprises the steps of weighing 20 parts of cellulose in parts by mass, soaking in a pre-treatment solution of which the mass percentage is 5-40%, washing by using distilled water after soaking for 1-48 hours, performing suction filtration to be neutral, adding 10-80 parts of oxidant in parts by mass and a catalyst which accounts for 0.01-5% of the mass of cellulose, stirring for 0.5-96 hours by using a magnetic stirrer, performing solid-liquid separation, washing a solid product by using the distilled water until the pH value is 7.0, and baking an obtained solid sample in a baking oven at 40-80 DEG C for 4-12 hours to obtain oxidized cellulose with different oxidation degrees. The method disclosed by the invention is relatively mild in reaction condition, simple in process and high in yield, does not have special requirements for equipment technologies, is convenient for industrial application, is low in preparation cost, can not generate any harmful by-products, is green and environment-friendly, and can not cause any hazards and pollutions to the environment.

The invention discloses crease-resistant finishing liquid for cotton fabric and application of the crease-resistant finishing liquid and belongs to textile finishing. The crease-resistant finishing liquid is characterized in that a laccase/TEMPO system is used to oxidize cellulose nanocrystals into aldehyde groups, the aldehyde groups and Girard's reagent T have Schiff base reaction to prepare positive ion modified cellulose nanocrystals, and the modified cellulose nanocrystals, 1,2,3,4-butanetetracarboxylic acid and chitosan are compounded to apply to the crease-resistant finishing of the cotton fabric. The crease-resistant finishing liquid has the advantages that the chitosan and the cellulose nanocrystals used by the finishing liquid are natural biomass materials and can copolymerize with BTCA on cotton fibers under high temperature to generate a long branched chain structure, and accordingly the cotton fabric after finishing has good crease resistance; in addition, by introducing the cellulose nanocrystals and the chitosan, the break strength retention and dyeing performance of the fabric after the crease-resistant finishing are improved, and the fabric is good in washing resistance stability and meets environment protection standards.

A refined oxidised cellulose (OC) material in various salt states having therapeutic treatments for skin. The micronized OC has a uniform particle size of the order of microns (0.001 to 0.050 mm). The OC is treated by further steps of oxidation, hydrolysis and refinement. The final product is chemically known as polyanhydroglucuronic acid, (PAGA). The salt versions of the OC are generally metal salts, such as sodium, calcium, zinc, copper, and silver.

Methods and devices for determining the healing status of wounds, in particular of chronic wounds are provided. Also provided are kits comprising the diagnostic devices, and methods of wound diagnosis and treatment using the diagnostic devices and methods. A diagnostic apparatus (device) for monitoring wounds that exude a wound fluid and determining whether said wounds would be responsive to treatment with wound therapy such as oxidized cellulose therapy is also provided along with kits comprising the diagnostic apparatus and a wound dressing. Furthermore, methods of prognosing and treating wounds that exude a wound fluid are also provided.