The present invention relates to a process for producing a low endotoxin alkali chitosan, chitin, chitosan derivative or chitin derivative, and also to a process for producing low endotoxin neutral chitosan, chitosan salt and chitosan derivatives, and to the products of such processes. The process comprises contacting chitosan, chitin, chitosan derivative or chitin derivative with an alkali solution having a concentration of less than 0.25M to form a mixture; leaving the mixture for a period of less than 12 hours and optionally drying the mixture. The low endotoxin alkali chitosan may be used in the manufacture of other useful chitosan based products.

Disclosed is a method of preparing N-alkylated chitosan derivatives by treating chitosan with an acid and subsequently reacting the chitosan with an alkylating agent in the presence of a base. Also provided are novel N-alkylated chitosan derivatives.

A thiol-modified hyaluronan, wherein the thiol-modified hyaluronan comprises a plurality of modification groups with a thiol-group in the hyaluronan side-chains, wherein the modification group comprises an amino acid residue with basic side chain and a conjugated terminal naturally occurring amino-thiol as well as a sterile hydrogel composition comprising a crosslinked polymer, wherein the crosslinked polymer is an oxidation product of the thiol-modified hyaluronan and uses of the composition.

The present invention concerns a method to prepare a filler with a hyaluronic acid, which has improved properties of chemical-physical stability over time and optimal viscosity for cutaneous injection. In particular the method comprises a first step in which the hyaluronic acid is crosslinked, and a subsequent step for the neutralization and hydration of the crosslinked hyaluronic acid.

The present invention relates to a method for preparing a chitosan succinate having excellent solubility and biocompatibility, and to a succinylated chitosan prepared thereby. The method for preparing a chitosan succinate according to the present invention can prepare a chitosan-based bio-substance having excellent hydrophilicity, cell proliferation rate, cell affinity, and cell proliferation performance through a simple process, thereby having excellent usability in vivo.

The present invention provides compositions comprising hyaluronan with high elasticity, as well as methods for improving joint function, reducing pain associated with joint function and treating osteoarthritis by introducing into a joint a therapeutically effective amount of a composition comprising hyaluronan with high elasticity.

Provided are an injectable intraocular microgel and an injectable intraocular hydrogel that are safe to a human body and that can release a drug in the eye for a long period of time. This injectable intraocular microgel may have a form in which a drug is loaded on a hyaluronic acid microgel generated by causing hyaluronic acid copolymers to cross-link with each other through a w/o emulsion method.

The present invention relates to the manufacture of a photo-crosslinkable biodegradable tissue adhesive using a multinetwork-forming copolymer, and provides a hyaluronic acid copolymer compound having excellent elongation, mechanical properties, and tissue adhesion. The compound fundamentally does not undergo phase separation, and enables the manufacture of a tissue adhesive with desired adhesive characteristics and physical characteristics.

The present invention relates to a hyperbranched polyglycerol polyglycidyl ether having a molecular weight from 750 to 15.000 Da; and an epoxy equivalent weight from 183 to 7.000 g/eq. It also relates to a crosslinked polysaccharide obtainable by crosslinking the polysaccharide with the hyperbranched polyglycerol polyglycidyl ether. The present invention also relates to processes for their preparation and their uses in therapy, cosmetic, agriculture and food field.

A macromolecular hyaluronic acid is used as a raw material, and is subjected to production processes such as hyaluronidase hydrolysis, heating and inactivation, activated carbon filtration, and spray and dry to obtain an ultra-low molecular weight hyaluronic acid product having an average molecular weight of less than 1200 Da. The product is a mixture of hyaluronic acid disaccharide to dodecaose. The content of hyaluronic acid disaccharide is 5-40%. The content of hyaluronic acid tetrasaccharide is 40-70%. The content of hyaluronic acid hexasaccharide is 10-30%. The content of hyaluronic acid octasaccharide is 1-15%. The content of hyaluronic acid decaose is 1-10%. The content of that higher than hyaluronic acid decaose is less than 6%. Compared with other available low molecular hyaluronic acid, the product has a more significant permeation, moisturizing, and repair promotion capability, and can be widely used in fields of medical products, health care products, cosmetics and the like.