69 results about "Chitosan scaffold" patented technology

The present invention relates to a layered chitosan scaffold wherein said layered scaffold comprises at least two fused layers, wherein at least one of the fused layers comprises a chitosan nanofiber membrane and the other fused layer comprises a porous chitosan support layer. Moreover, the present invention provides a layered chitosan scaffold characterized by (i) a good adhesion between the porous and nanofiber layers, (ii) a tuneable porosity of the nanofiber layer by tuning the distance between the nanofibers, (iii) a stable nanofibers and porous morphology even when immersed in water or other solvents and a process for the preparation of such layered chitosan scaffold. The present invention also provides a process for the preparation of the layered chitosan scaffold.

The invention discloses an alkaline solvent for dissolving high-molecular-weight chitosan, which can be used for dissolving chitosan with the molecular weight of between 1 million and 6 million. The alkaline solvent comprises the following components in percentage by weight: 1.0-5.0 percent of lithium hydroxide, 0-4.0 percent of sodium hydroxide, 4.0-9.0 percent of urea, 0.1-3.0 percent of glycerin and the balance of water. By adopting the solvent disclosed by the invention, the problem of great reduction in the intensity of a product caused by degradation of the high-molecular-weight chitosan in an acid solvent can be solved. A using method of the solvent disclosed by the invention is simple. A solution in which the high-molecular-weight chitosan is dissolved can be used for researching the relation between the dissolution behavior and the molecular structure of the high-molecular-weight chitosan, and can be applied to processing of products such as high-intensity chitosan gel, chitosan fibers, chitosan bar materials, chitosan bracket materials and the like.

A dual-layer scaffold for the skin regeneration is composed of a porous collagen-chitosan scaffold for inducing the migration, reproduction and differentiation of cells and the generation of dermal tissue and a silica rubber film as temporary epidermal layer for preventing the volatilization of water and the intrusion of bacteria. It has high biocompatibility, controllable degradation speed and excellent wound repairing power.

The present invention provides a method for achieving assembly of a macroscopic size nanometer material and obtaining a series of functional nanometer composite scaffolds by adopting a chitosan scaffold as a matrix, wherein the series of the functional nanometer composite scaffolds are obtained by assembling various functional nanometer materials in a chitosan scaffold. The method specifically comprises that: unidirectional freezing is performed to obtain a chitosan porous scaffold, the chitosan porous scaffold is immersed into a nanometer material aqueous solution, and the nanoparticles are adsorbed onto the surfaces of pore channels inside the chitosan porous scaffold so as to obtain the nanometer composite scaffold; or a nanometer material is directly mixed in a chitosan solution before a chitosan porous scaffold is obtained, and then unidirectional freezing is performed to obtain the nanometer composite chitosan porous scaffold. The method of the present invention has characteristics of simple operation and wide applicability, and can be applicable for mass preparation of required products. According to the nanometer composite scaffold of the present invention, the reversible shape resilience performance of the original chitosan porous scaffold is provided, and the functionality of the nanometer material is provided for the final macroscopic scaffold, such that important guiding effects are provided for applications of various functional nanometer materials in optics, electricity, magnetism, thermotics, biomedicine, and other fields.

The present invention relates to an electrospun chitosan scaffold. The scaffold mimics natural bone mechanical properties and structure through mineralization without hindering the biocompatibility for osteoblasts. The electrospun mineralized scaffold is useful in bone regeneration therapies.

The present invention relates to a porous scaffold with controllable microstructure, proper degradation rate and good biological compatibility prepared by using natural biological materials of collagen and chitosan as raw material and adopting the processes of freeze-freeze drying, further vacuum drying and heating and cross-linking of aldehyde compound or carbodiimide compound. The biological compatibility of said invented collagen/chitosan scaffold is good, its degradation rate can be controlled, and its raw material source is extensive and its cost is low, and its reproducibility is good. Said scaffold can be extensively used in the field of tissue engineering technology.

The invention discloses a porous chitosan scaffold, and a neural stem cell porous chitosan scaffold and application thereof. A method for preparing the porous chitosan scaffold comprises the following steps of: dissolving chitosan in acetic acid to form 2 percent solution, adding the solution into pores of a cell culture plate, freeze-drying, adding NaOH into the pores of the cell culture plate for hydration, and freeze-drying twice at the temperature of -60 DEG C to obtain the porous chitosan scaffold. A method for preparing the neural stem cell porous chitosan scaffold comprises the following steps of: inoculating neural stem cell clone spheres to the sterilized porous chitosan scaffold in the culture spores, and adding a DMEM/F12 serum-free culture medium or an NGF-containing DMEM/F12 serum-free culture medium for culture to obtain the neural stem cell porous chitosan scaffold. The chitosan porous scaffold prepared by a low-temperature freeze-drying method has uniform pores, the porosity of 90 percent, the average pore size of 50 to 350mu m and high biocompatibility with neural stem cells (NSCs). Traumatic brain injury (TBI) is treated by transplanting the NSCs using chitoson as a carrier, and cognitive functions after injury, such as learning, memorizing and the like can be obviously improved.

The invention belongs to the technical field of new materials, and particularly relates to a preparation method of a crosslinked chitosan/gelatin composite porous scaffold. According to the method, chitosan, gelatin and other natural biological materials are used as raw materials, an organosilane coupling agent is used as a crosslinking agent, and a freeze-drying process is utilized to prepare the excellent-mechanical-property crosslinked chitosan/gelatin composite porous scaffold composed of pure natural biological materials. The crosslinked chitosan/gelatin composite porous scaffold has the characteristics of high porosity, high pore strength, large pore diameter and the like; the pore size is 100-300 mu m, and the porosity is 90%; and the crosslinked chitosan/gelatin composite porous scaffold is in an open pore structure in which larger pores contains smaller pores, and thus, cells are suitable to be implanted on the scaffold surface. Compared with the chitosan scaffold, the crosslinked chitosan/gelatin composite porous scaffold has better mechanical properties; and the addition of the gelatin and organosilicon crosslinking agent is more beneficial to proliferation and differentiation of cells on the porous scaffold surface, and the crosslinked chitosan/gelatin composite porous scaffold has higher affinity for biological cells.

The invention relates to a preparation method of a nano micrometer structure coexistence chitosan double-layer support, which belongs to the biology medical material field. The preparation method is characterized in that a phase separating technology is used to prepare a three-dimensional micrometer chitosan support as a basal layer, a high voltage static static spinning technology is used for spinning nano chitosan fiber on the micrometer chitosan surface, and thereby the nano micrometer structure coexistence chitosan double-layer support can be obtained. The prepared double layer support has good mechanical strength and high amount of porosity, and is suitable for adhesion, growth and differentiation of cells. The surface layer chitosan nano fiber is suitable for growth of cartilage cells, the basal layer micrometer chitosan support is suitable for the growth of the osteoblast, and the nano micrometer structure coexistence chitosan double-layer support can be used for restoring joint position of the human body cartilage and hard bone.

The invention discloses a galactosylated chitosan scaffold material for a bioartificial liver, which is a galactosylated chitosan biological material with a three-dimensional porous structure which is cross-linked by an oxidized sodium alginate biological crosslinking agent. Its main preparation process: chitosan and lactobionic acid are dissolved in tetramethylethylenediamine/hydrochloric acid mixed solution in an equimolar ratio, and active intermediates are added to activate the reaction to prepare galactosylated chitosan; galactosylated chitosan is dissolved in Acetic acid solution and oxidized sodium alginate are dissolved in ultrapure water, and the two solutions are mixed in a certain proportion to carry out cross-linking reaction. After the reaction is completed, pour it into a mold for molding, freeze-dry to obtain a scaffold material, and then immerse it in sodium hydroxide- The residual acetic acid was removed by ethanol aqueous solution, and then washed by ethanol aqueous solution and freeze-dried twice to obtain the galactosylated chitosan scaffold material cross-linked by oxidized sodium alginate. The galactosylated chitosan scaffold material of the invention has a pore size suitable for the growth of liver cells and good biocompatibility.

The invention provides a method for preparing a chitosan three-dimensional scaffold having graphene oxide coatings of different reducing degrees. The method specifically comprises the following steps: preparing a chitosan scaffold material having a porous structure by a freeze drying method; then soaking the chitosan scaffold material in graphene oxide dispersion fluids of different concentrations; adsorbing graphene oxide sheets to pore walls of chitosan through the electrostatic interaction and the hydrogen-bond interaction; drying, and finally carrying out gradient heating and reducing to obtain the chitosan scaffold which has greatly improved mechanical strength and has graphene oxide coatings of different reducing degrees. The chitosan scaffold has a good application prospect in the aspect of neural tissue engineering. The method provided by the invention is simple to operate and can be used for preparing a great amount of desired product.

The present invention relates to a preparation method of a silk fibroin/gelatin fiber reinforced chitosan composite haemostatic material. The preparation method comprises the following steps that S1,a silk fibroin aqueous solution is mixed with a gelatin aqueous solution, and a mixed solution is concentrated until a certain concentration of silk fibroin is reached; S2, through an electrostatic spinning method, the mixed solution in the step S1 is prepared into a silk fibroin/gelatin composite fiber felt; S3, the silk fibroin/gelatin composite fiber felt is subjected to post-treatment and high-speed shearing, thereby preparing fiber water dispersion liquid; S4, a chitosan solution is prepared; S5, the composite fiber aqueous solution and the chitosan solution are mixed according to a certain mass ratio; and S6, a mixed solution in the step S5 is freeze-dried to obtain a three-dimensional porous scaffold, and post-treatment is performed to obtain a silk fibroin/gelatin/chitosan scaffold. Compared with the prior art, the silk fibroin and gelatin are prepared into composite fiber, and the composite fiber as a reinforcing material is added to a chitosan matrix to prepare a ternary composite hemostatic material, thereby improving the mechanical properties and the hemostatic performance of a pure chitosan material.

The invention discloses a filling rack perfusion biological reactor of artificial liver in the medically biological technical domain, which is characterized by the following: the appearance is cylinder shaped container; the liquid outlets 1 and 2 are upper and lower ends of the cylinder container; the outlet 3 and 4 are distributed in the center of lateral wall symmetrically; the physical rack 6 has 14-16 biological racks as crossing arrangement to deposit separation area and support liver cell; the liquid buffer area 7 is set in the middle of the inner rack of the reactor; setting cell screen and cell screen brush at outlet; connecting the upstream of two outlets of biological reactor with membrane oxygenator 14; connecting the downstream of two outlets with immune adsorber 15; the biological rack of the liver cell is chitose rack or alginic acid/chitose and modified alginic acid/galactose chitose/heparin rack; possessing good biological compatibility; fitting for growing liver cell and developing the function; avoiding collapse of the biological rack of the liver cell.

The present invention discloses a method of preparing a functional chitosan scaffold and said functional chitosan scaffold for use as a filtering medium. Said method involves freeze-drying chitosan in the presence of appropriate cross-linkers and additives. The present chitosan scaffold is associated with an increased mechanical strength and elasticity and an adjustable surface polarity, porosity and morphology which enable its use in a wide range of devices, equipments and appliances in need of a filtering medium such as air or water purification system.

The invention discloses a preparation method for composite hydrogel and belongs to the technical field of polymers. The preparation method comprises the following steps: firstly, preparing hydroxyapatite (HA) and chitosan (CS) into solution; secondly, doping the solution in a polyacrylamide (PAM) network structure. According to the preparation method, the preparation process is simple and convenient to operate and the cost is reduced; besides, the obtained material overcomes the defects that a CS stent is easily bent and is poor in mechanical property, and retains good mechanical properties of tensile strength and compression resistance endowed by the HA; in the preparation process, the HA and the CS which have good biocompatibility are doped in the PAM network structure, and good mechanical properties are endowed for a hydrogel material. Therefore, the composite material can be used as a replacement material of cartilage and has potential application value in the tissue engineering.

The invention discloses a method for preparing a high-intensity three-dimensional chitosan porous bracket. The method comprises the following steps: taking a chitosan as a raw material; taking n-amyl alcohol and water as pore-forming agents; preparing the three-dimensional chitosan porous bracket according to an emulsion freeze drying method; and utilizing a microwave oven to perform the microwave radiation treatment on the three-dimensional chitosan porous bracket, thereby finally obtaining the high-intensity three-dimensional chitosan porous bracket. The high-intensity three-dimensional chitosan porous bracket prepared according to the method for preparing the high-intensity three-dimensional chitosan porous bracket provided by the invention has a pore diameter of 20-50m and a porosity of 92%; the microwave radiation is utilized to generate a heat effect; the three-dimensional chitosan porous bracket is subjected to a cross-linking reaction, thereby forming a three-dimensional netted structure; the mechanical property of the finally obtained high-intensity three-dimensional chitosan porous bracket is obviously increased; and the prepared high-intensity three-dimensional chitosanporous bracket can be applied to the suspension culture of adherence cells.

Porous chitosan scaffold having high mechanical strength, methods for making the porous chitosan scaffold, and method for using the porous chitosan scaffold.

Nasal or sinus site may be treated with a ready-to-use paste having a high concentration of a water-soluble chitosan, an osmolality reducing agent in a phosphate-containing solution. The paste forms at room temperature, has a pH of at least 4 and the osmolality reducing agent does not crosslink with the water-soluble chitosan. The paste provides stenting and adheres to the nasal or sinus site and has a residence time of at least 1 day.

The invention discloses a preparation method of a dental pulp stem cell and chitosan scaffold complex. The preparation of the dental pulp stem cell and chitosan scaffold complex is finished through steps of separation and primary culture of human dental pulp stem cells, chondrogenic differentiation and identification of the dental pulp stem cells, adipogenic differentiation and identification of the dental pulp stem cells, preparation of a porous chitosan scaffold and co-culture. According to the chitosan scaffold prepared by the invention, an adhesion condition between the dental pulp stem cells and chitosan is observed under an electron microscope, so as to effectively testify that the dental pulp stem cells and the chitosan have good biological compatibility; meanwhile, the chitosan scaffold has no toxic responses on the dental pulp stem cells.

The invention belongs to the technical field of novel materials and in particular relates to a method for preparing a crosslinked chitosan porous scaffold. The method comprises the following steps: by taking a chitosan natural biomaterial as a raw material and an organic silane coupling agent KH-560 as a cross-linking agent, preparing the crosslinked chitosan porous scaffold which is excellent in mechanical property and consists of pure natural biomaterials by adopting a freeze drying method. The prepared crosslinked chitosan porous scaffold has the large pore diameter of 100-300 mu m and the high porosity of more than 90 percent, is in an open hole structure in which a large pore contains a small pore, and is suitable for cell implantation on the scaffold surface. Compared with a chitosan scaffold, the crosslinked chitosan porous scaffold has higher mechanical property; due to the added organic silane coupling agent, the cell proliferation and differentiation on the surface of the porous scaffold are promoted, and the affinity to biological cells is high.

The invention discloses a method for preparing a porous chitosan scaffold. The method comprises the following steps of: preparing an acid solution of chitosan in which a set amount of ammonium chloride is dissolved; injecting the solution into a mold for primary freeze drying; soaking the scaffold subjected to freeze drying in a sodium hydroxide solution for set time, and cleaning the scaffold with distilled water; and performing secondary freeze drying on the scaffold to obtain the porous chitosan scaffold. By the method for preparing the porous chitosan scaffold, the porosity and the communication between holes of the chitosan scaffold can be increased.