Abstract: A core-shell gel particle of the invention contains a crosslinked hyaluronic acid, has a higher equilibrium swelling capacity at the surface than at the center, the equilibrium swelling capacity showing a change curve with an inflection point from the center to the surface, and has a probe pushing force of 20 nN or less from the surface to a depth of 800 nm.

Abstract: Provided is an agent for preserving a biological component, comprising a hydrogel, the hydrogel comprising a crosslinked product formed from a compound having a plurality of hydroxyl groups and a modified hyaluronic acid having substituents capable of reacting with the hydroxyl groups to form a crosslinked structure.

Abstract: A core-shell gel particle of the invention contains a crosslinked hyaluronic acid, has a higher equilibrium swelling capacity at the surface than at the center, the equilibrium swelling capacity showing a change curve with an inflection point from the center to the surface, and has a probe pushing force of 20 nN or less from the surface to a depth of 800 nm.

Abstract: Provided is an agent for preserving a biological component, comprising a hydrogel, the hydrogel comprising a crosslinked product formed from a compound having a plurality of hydroxyl groups and a modified hyaluronic acid having substituents capable of reacting with the hydroxyl groups to form a crosslinked structure.

Abstract: A core-shell gel particle of the invention contains a crosslinked hyaluronic acid, has a higher equilibrium swelling capacity at the surface than at the center, the equilibrium swelling capacity showing a change curve with an inflection point from the center to the surface, and has a probe pushing force of 20 nN or less from the surface to a depth of 800 nm.

Abstract: The present invention provides a crosslinked hyaluronic acid composition including self-crosslinking hyaluronic acid particles having an equilibrium swelling capacity of 3-fold to 10-fold, and an aqueous solvent, wherein a dry weight of the self-crosslinking hyaluronic acid particles based on the total volume of the crosslinked hyaluronic acid composition is 3 w/v % to 8 w/v %. The crosslinked hyaluronic acid composition of the invention uses self-crosslinking hyaluronic acid particles of which the equilibrium swelling capacity is within the above predetermined range. Accordingly, the viscosity does not sharply increase even if the concentration thereof is increased. Therefore, if the crosslinked hyaluronic acid composition is applied to an injection, it is possible to obtain a sufficient curative effect on knee osteoarthritis even with a small frequency of administration.

Abstract: It is intended to provide a simple method for producing hyaluronic acid at a high yield. Further, it is also intended to provide a method for producing hyaluronic acid in a short period of time. The invention provides a method for producing hyaluronic acid including a step of culturing a microorganism having the capability to produce hyaluronic acid and a step of adding glutamine and arginine to a culture medium during late logarithmic growth phase of the microorganism.

Abstract: The present invention provides a crosslinked hyaluronic acid composition including self-crosslinking hyaluronic acid particles having an equilibrium swelling capacity of 3-fold to 10-fold, and an aqueous solvent, wherein a dry weight of the self-crosslinking hyaluronic acid particles based on the total volume of the crosslinked hyaluronic acid composition is 3 w/v % to 8 w/v %. The crosslinked hyaluronic acid composition of the invention uses self-crosslinking hyaluronic acid particles of which the equilibrium swelling capacity is within the above predetermined range. Accordingly, the viscosity does not sharply increase even if the concentration thereof is increased. Therefore, if the crosslinked hyaluronic acid composition is applied to an injection, it is possible to obtain a sufficient curative effect on knee osteoarthritis even with a small frequency of administration.

Abstract: It is intended to provide a simple method for producing hyaluronic acid at a high yield. Further, it is also intended to provide a method for producing hyaluronic acid in a short period of time. The invention provides a method for producing hyaluronic acid including a step of culturing a microorganism having the capability to produce hyaluronic acid and a step of adding glutamine and arginine to a culture medium during late logarithmic growth phase of the microorganism.

Abstract: A biodegradable composition containing an antibiotic or a physiologically active substance for use in surgical treatment of infection. A highly safe and biocompatible composition showing appropriately sustained release of an antibiotic or physiologically active substance which produces excellent antibiotic and bone regenerating effects. A composition having excellent effects in treatment of bone infection occurring after operations for total arthroplasty and/or bone fracture. (1) A medical composition for treatment of bone infection comprising an antibiotic and a polysaccharide.

Abstract: A separate type medical material containing a hyaluronic acid ester derivative, which satisfies the storage stability of a hyaluronic acid ester derivative and avoidance of irritation and pain at the time of injecting a therapeutic agent for joints, is provided. A separate type medical material comprising liquid (A) which is an aqueous solution containing a hyaluronic acid ester derivative and buffered to a pH of from 4.5 to 6.5, and liquid (B) which is an aqueous solution having such a buffering power that when it is mixed with the liquid (A), the mixed liquid has a pH within a range of from 6.8 to 7.8, kept separately from each other.

Abstract: A separate type medical material containing a hyaluronic acid ester derivative, which satisfies the storage stability of a hyaluronic acid ester derivative and avoidance of irritation and pain at the time of injecting a therapeutic agent for joints, is provided. A separate type medical material comprising liquid (A) which is an aqueous solution containing a hyaluronic acid ester derivative and buffered to a pH of from 4.5 to 6.5, and liquid (B) which is an aqueous solution having such a buffering power that when it is mixed with the liquid (A), the mixed liquid has a pH within a range of from 6.8 to 7.8, kept separately from each other.

Abstract: A biodegradable composition containing an antibiotic or a physiologically active substance for use in surgical treatment of infection. A highly safe and biocompatible composition showing appropriately sustained release of an antibiotic or physiologically active substance which produces excellent antibiotic and bone regenerating effects. A composition having excellent effects in treatment of bone infection occurring after operations for total arthroplasty and/or bone fracture. (1) A medical composition for treatment of bone infection comprising an antibiotic and a polysaccharide.

Abstract: A separate type medical material containing a hyaluronic acid ester derivative, which satisfies the storage stability of a hyaluronic acid ester derivative and avoidance of irritation and pain at the time of injecting a therapeutic agent for joints, is provided. A separate type medical material comprising liquid (A) which is an aqueous solution containing a hyaluronic acid ester derivative and buffered to a pH of from 4.5 to 6.5, and liquid (B) which is an aqueous solution having such a buffering power that when it is mixed with the liquid (A), the mixed liquid has a pH within a range of from 6.8 to 7.8, kept separately from each other.

Abstract: A gel made of hyaluronic acid alone which is hardly soluble in a neutral aqueous solution and which keeps its shape for at least one day in a neutral aqueous solution at 25° C.

Abstract: A hyaluronic acid gel composition comprising hyaluronic acid and a polymer, which is substantially unmodified with a chemical cross-linking agent or a chemical modifying agent and which has a percentage dissolution of hyaluronic acid of 50% or lower in 12 hours in a neutral aqueous solution of 37° C.

Abstract: A gel made of hyaluronic acid alone which is hardly soluble in a neutral aqueous solution.

Abstract: A gel made of hyaluronic acid alone which is hardly soluble in a neutral aqueous solution and which keeps its shape for at least one day in a neutral aqueous solution at 25° C.

Abstract: A method for producing sodium hyaluronate by a fermentation method comprises culturing a mutant strain FM 100 derived from Streptococcus equi and partially free from auxotrophy to thereby stably produce sodium hyaluronate and accumulating the hyaluronate. A method for producing sodium hyaluronate by a fermentation method comprises culturing a mutant strain FM 300 derived from Streptococcus equi and partially free from auxotophy to thereby stably produce sodium hyaluronate and accumulating the hyaluronate.