2784 results about "Fibroin" patented technology

A method was developed to prepare silk fibroin microspheres using lipid vesicles as templates to efficiently load therapeutic agents in active form for controlled release. The lipids are subsequently removed through the use of a dehydration agent, such as methanol or sodium chloride, resulting in β-sheet structure dominant silk microsphere structures having about 2 μm in diameter. The therapeutic agent can be entrapped in the silk microspheres and used in pharmaceutical formulations for controlled-release treatments.

The present invention provides for concentrated aqueous silk fibroin solutions and an all-aqueous mode for preparation of concentrated aqueous fibroin solutions that avoids the use of organic solvents, direct additives, or harsh chemicals. The invention further provides for the use of these solutions in production of materials, e.g., fibers, films, foams, meshes, scaffolds and hydrogels.

The present invention provides for novel sustained release silk-based delivery systems. The invention further provides methods for producing such formulations. In general, a silk fibroin solution is combined with a therapeutic agent to form a silk fibroin article. The article is then treated in such a way as to alter its conformation. The change in conformation increases its crytallinity or liquid crystallinity, thus controlling the release of a therapeutic agent from the formulation. This can be accomplished as single material carriers or in a layer-by-layer fashion to load different therapeutic agents or different concentrations of these agents in each layer.

There is provided a novel wound dressing material which has biocompatibility and infection controllability as essential properties required for such a material, especially excellent flexibility and water absorption properties, thereby accelerating smooth regeneration of a skin defect without stripping off the regenerating skin while removing the material from the skin. A healing agent is added to the wound dressing material which comprises an amorphous film of a crystallinity below 10% and contains fibroin and sericin as a main component.

The present specification provides for methods for purifying fibroins, purified fibroins, methods of conjugating biological and synthetic molecules to fibroins, fibroins conjugated to such molecules, methods of making fibroin hydrogels, fibroin hydrogels and fibroin hydrogel formulations useful for a variety of medical uses, including, without limitation uses as bulking agents, tissue space fillers, templates for tissue reconstruction or regeneration, cell culture scaffolds for tissue engineering and for disease models, surface coating to improve medical device function, or drug delivery devices.

This invention provides for a process of rapidly forming silk fibroin gelation through ultrasonication. Under the appropriate conditions, gelation can be controlled to occur within two hours after the ultrasonication treatment. Biological materials, including viable cells, or therapeutic agents can be encapsulated in the hydrogels formed from the process and be used as delivery vehicles.

The invention provides a method for the controlled assembly of layered silk fibroin coatings using aqueous silk fibroin material. The methods described herein can be used to coat substrates of any material, shape, or size. Importantly, the described methods enable control of the biomaterial surface chemistry, thickness, morphology and structure using layered thin film coatings, or bulk coatings. Furthermore, the methods can be performed in all water and do not require intensive chemical processing enabling controlled entrapment of labile molecules such as, drugs, cytokines, and even cells or viruses to generate functional coatings that can be used in a variety of applications.

The present invention relates to a membrane for guided bone tissue regeneration and, more particularly, to a membrane for guided bone tissue regeneration having a structure that silk fibroin nanofibers obtained by removing sericin from silk fibers are formed as a nonwoven, and a manufacturing method thereof. A membrane for guided bone tissue regeneration according to the present invention has a predetermined strength, biocompatibility, and biodegradability, and may maintain a sustained drug release system, when drugs are added in the manufacturing process. Additionally, a membrane for guided bone tissue regeneration according to the present invention may be modified corresponding to the condition of usage, because a thickness of the membrane may be adjusted by controlling fineness of nanofibers, compactness of nanofibers, and pore size of a multiporous structure may be adjusted, in a nonwoven manufacturing process. A nanofibrous membrane for guided bone tissue regeneration according to the present invention is manufactured by freezing rapidly, drying a silk fibroin solution obtained by removing sericin from silk fibers, and by electrospinning after dissolving the dried silk fibroin in an electrospinning solvent. The membrane according to the present invention has excellent adhesion and air permeability, and is thereby effective in regeneration of damaged periodontal tissues.

The present invention provides processes for producing porous silk fibroin scaffold material. The porous silk fibroin scaffold can be used for tissue engineering. The porosity of the silk fibroin scaffolds described herein can be adjusted to mimic the gradient of densities found in natural tissue. Accordingly, methods for engineering of 3-dimensional tissue, e.g. bone and cartilage, using the silk fibroin scaffold material are also provided.

This invention relates to a lamellae tissue layer, comprising a grooved silk fibroin substrate comprising tissue-specific cells. The silk fibroin substrates provides an excellent means of controlling and culturing cell and extracellular matrix development. A multitude of lamellae tissue layers can be used to create a tissue-engineered organ, such as a tissue-engineered cornea. The tissue-engineered organ is non-immunogenic and biocompatible.

The invention discloses a silk fibroin nanofiber membrane and a preparation method of the silk fibroin nanofiber membrane. The preparation method comprises the following specific steps of: dissolving natural silk taken as a main raw material by an acid salt solution, forming a membrane, desalting the membrane, dissolving the membrane by methanoic acid and hexafluoroisopropanol to prepare a spinning solution, and carrying out electrostatic spinning to prepare the silk fibroin nanofiber membrane. The silk fibroin nanofiber membrane comprises fibers with the diameter of 10nm-10 microns and has the excellent mechanical property, the breaking strength of greater than 8Mpa at dry state, the breaking elongation of greater than 15% at dry state, the breaking strength of greater than 1Mpa at wet state and the breaking elongation of greater than 100% at wet state. In addition, the silk fibroin nanofiber membrane prepared by the method is stable and controllable in structure, has good biocompatibility and can serve as a medicinal biological material. The preparation method disclosed by the invention is simple and short in flow path, has high film formation and spinning efficiency and is suitable for industrialization large-scale production.

A process for producing non-woven silk fiber fabrics comprises the following steps: a) obtaining silk fibroin, for example either from silk cocoons, or silk textiles or waste silk; b) removing the sericin layer covering the silk fibroin fibers, when present; c) breaking the disulfide bonds between heavy (350 kDa) and light (27 kDa) chains of silk fibroin in order to obtain the production of chain fragments which serve as a specific cellular recognition sites promoting the attachment and growth of cells, d) homogenising of the material resulting from step c).

The present invention provides a novel silk-fiber-based matrix having a wire-rope geometry for use in producing a ligament or tendon, particularly an anterior cruciate ligament, ex vivo for implantation into a recipient in need thereof. The invention further provides the novel silk-fiber-based matrix which is seeded with pluripotent cells that proliferate and differentiate on the matrix to form a ligament or tendon ex vivo. Also disclosed is a bioengineered ligament comprising the silk-fiber-based matrix seeded with pluripotent cells that proliferate and differentiate on the matrix to form the ligament or tendon. A method for producing a ligament or tendon ex vivo comprising the novel silk-fiber-based matrix is also disclosed.

The present specification provides drug delivery platforms useful for the controlled release of a compound over time in an individual.

The invention discloses bio-medical engineering material and preparation method thereof, particularly relates to 3D tissue repair material suitable for adhesively growing of cell and preparation method thereof, belonging to bio-medical material technique domain. The natural tussah silk is used as raw material. After antheraea pernyi silk fibroin dissolves, 3D non-woven web structure composed of antheraea pernyi silk fibroin fibre is obtained by electrostatic spinning, wherein the fibre diameter is 50nm-20 mu m, the hole between the fibres is 1-500 mu m, the thickness of non-woven web is 50nm-20mm, and molecular weight of the antheraea pernyi silk fibroin is 10X10<4>-20X10<5>D. The bio-medical engineering material has features of non-poison, harmless, good biocampatibility, good adhesive growth ability of cell, etc. Because of the wide materials supply and low cost, the said material will replace some high-cost bio-medical material such as collagen, and will be used for repair material such as artificial skin, tendon, cartilage, duramater and so on, particularly for histiocyte induction material.

The invention provides a composite repair material which facilitates surgical operation and realizes quick defect nerve bridging and composition, preparation and application of a stent made of the composite repair material. The composite repair material consists of a fibroin layer, a collagen layer and a high-molecular polymer layer which are sequentially arranged, and during application, the composite repair material is folded or wound to form the nerve bridging stent taking the fibroin layer as the inner layer, the collagen layer as the middle layer and the high-molecular polymer as the outer layer. The composite repair material and the stent made of the composite repair material adopt the layered arrangement and a specific three-dimensional design to bring the advantages of various repair materials into full play, and meanwhile, make up for the deficiencies of the various repair materials. During surgical operation, only suturing or bonding anastomosis of epineurium is required but not suturing of perineurium, so that the operation time of a defect nerve bridging operation is greatly shortened, the operation technical difficulty is lowered, and the security is improved.

The present invention provided for a novel process of forming silk fibroin gels, and controlling the rate of β-sheet formation and resulting hydrogelation kinetics, by vortex treatment of silk fibroin solution. In addition, the vortex treatment of the present invention provides a silk fibroin gel that may be reversibly shear-thinned, enabling the use of these approach for precise control of silk self-assembly, both spatially and temporally. Active agents, including biological materials, viable cells or therapeutic agents, can be encapsulated in the hydrogels formed from the processes, and be used as delivery vehicles. Hence, the present invention provide for methods for silk fibroin gelation that are useful for biotechnological applications such as encapsulation and delivery of active agents, cells, and bioactive molecules.

The invention relates to a tissue engineering material and a preparation method thereof, in particular to a nano fiber tissue engineering blood vessel and a preparation method thereof. The invention consists of a three-dimensional reticular non-woven film formed by an inner layer of nano fiber and an outer layer of nano fiber; the inner layer of the blood vessel is natural polymer, wherein, calculated by weight, 40 percent to 80 percent is fibroin, 20 percent to 50 percent is gelatine, 0 percent to 20 percent is extracellular matrix protein; while the outer layer of the blood vessel is synthetic polymer. The preparation method is that the natural polymer is dissolved in trifluroroethyl and other solution, while the synthetic polymer is dissolved in hexafluoroisopropanol and other solution, which are respectively prepared into spinning solution; the static electricity spinning technique is adopted to subsequently form the inner and the outer layers on a gather roller; cross-linked treatment is conducted after the inner and the outer layers are taken down, to prepare the nano fiber tissue engineering vessel. The inner layer can simulate the structure of the extracellular matrix, provide good environment for endothelial cells to grow, support adhesion, proliferation and differentiation of the cells, and is good for endothelization of the blood vessel; and the outer layer has good mechanical performance.

The present invention provides for compositions and methods for preparing aqueous insoluble, ductile, flexible silk fibroin films. The silk films comprise silk fibroin and about 10% to about 50% (w/w) glycerol, and are prepared by entirely aqueous processes. The ductile silk film may be further treated by extracting the glycerol from and re-drying the silk film. Active agents may be embedded in or deposited on the glycerol modified silk film for a variety of medical applications. The films may be into 3-dimentional structures, or placed on support surfaces as labels or coatings. The glycerol modified silk films of the present invention are useful in variety of applications such as tissue engineering, medical devices or implants, drug delivery, and edible pharmaceutical or food labels.

The invention provides a method for preparing graphene/ silk composite fiber. The method comprises the steps of: oxidizing graphite powder by using acid, and carrying out ultrasonic dispersing and stripping to obtain graphene solution; mixing the obtained graphene solution with degummed silk fibroin and formic acid to obtain spinning solution; and carrying out electrospinning on the spinning solution by an electrostatic spinning device to obtain the graphene/ silk composite fiber. The method is simple in preparation technology, can effectively improve the mechanical property of the silk fiber and is easy to popularize and use.

The invention discloses a bioactive tissue regeneration membrane and a preparing method thereof. The membrane is double compound layer. One layer is a tissue isolation layer which comprises silk fibroin, and the other layer is a tissue orientation layer which comprises silk fibroin bundles adhered on the tissue isolation layer or silk fibroin bundles mixed with bioactive factors. One side of the membrane is a smooth dense shape, and the other side is a loose porous structure. In the preparing method of the bioactive tissue regeneration membrane, the silk fibroin solution is swollen, stirred, deaerated and casted into membrane to obtain the tissue isolation layer. One side of the tissue isolation layer is scratched to be coarsened. Then, the silk fibroin solution or the silk fibroin solution mixed with the bioactive factors is coated or sprayed on the scratched layer by an electrostatic spinning method. After freezing and vacuum drying demoulding, the membrane is obtained. The membranehas the advantages of nontoxic and harmless property, perfect biocompatibility, good cell adhering growth property, abundant raw material and low cost and can substitute bio-medical materials of collagen and the like and widely applied to a plurality of clinical subjects.