A method of preparing a hydrogel product comprising crosslinked glycosaminoglycan molecules, said method including: i) providing a glycosaminoglycan crosslinked by amide bonds, wherein the crosslinked glycosaminoglycans include ester crosslinks formed as byproducts during the amide crosslinking; and ii) subjecting the crosslinked glycosaminoglycans to alkaline treatment to hydrolyze ester crosslinks formed as byproducts during the amide crosslinking.

Disclosed are a sustained-release injection formulation containing a biodegradable polymer microcapsule that contains a conjugate of poly-L-lactic acid (hereinafter referred to as “PLLA”) filler and hyaluronic acid (hereinafter referred to as “HA”) and contains a PLLA-HA microcapsule, and a method of preparing the same.

The present invention discloses polyglycol epoxide crosslinked sodium hyaluronate gel for injection and a preparation method thereof. A polyglycol epoxide is a compound with single molecular weight preferably; a plurality of ether bonds are present in the molecule of the polyglycol epoxide, the water solubility is good, and thus, the polyglycol epoxide is more easily subjected to a crosslinking reaction with polysaccharides; and meanwhile, polyglycol is relatively easy in adjustment of the number of repeating units and relatively easy in control of length, and thus, the sodium hyaluronate gel prepared by taking the polyglycol epoxide as a crosslinker is relatively easy in regulation and control of properties. The crosslinked sodium hyaluronate gel is low in toxicity, little in residual, small in squeezing and pushing force, good in shaping performance, good in enzyme resistance and long in in-vivo retention time. The present invention further discloses a mild crosslinker deactivation technology. Unreacted epoxide groups in the gel are subjected to a hydrolysis reaction in a carbonate buffer system with a pH of 8-9, so that the difficulty of impurity removal of the crosslinked sodium hyaluronate gel can be effectively lowered, and the problem of toxicity in the prior art due to the fact that BDDE is used in a crosslinking method is avoided.

A method for forming a chitin film is provided. The method includes the following steps. In a step (a), a chitin suspension is prepared by adding chitin to water. In a step (b), physical forces are provided to process the chitin suspension, so that a mean particle diameter of the chitin is reduced. In a step (c), the chitin suspension is applied to a target, and the chitin film is formed after the chitin suspension is dried.

The present invention relates to a hyaluronic acid-based dissolving film, a production method thereof, and a release liner used for the same, and more particularly to a method for producing a hyaluronic acid-based dissolving film that provides a hyaluronic acid-based dissolving film having high performance with high productivity through a continuous production process to allow mass production of the dissolving film, a hyaluronic acid-based dissolving film produced by the method, and a release liner suitable for the dissolving film.

A bioresorbable, sustained release pharmaceutical composition comprising: 1.8 wt % to 3.0 wt % methylcellulose and 0.1 wt % to 3.0 wt % hyaluronan in the form of a gel polymer matrix, and at least one local anesthetic agent, suitably ropivacaine, which may be administered by injection.

Provided is a method that achieves tunable crosslinking and reversible phase transition of hydrogels. The method is useful for preparing 3D-printable hydrogel, for example, for wound healing, aneurysm treatment or tissue regeneration.

This application relates to a thermo-gel polymer system useful for ophthalmic drug delivery. The thermo-gel comprises a polymer and chitosan, and the polymer comprises monomers of N-isopropylacrylamide (NIPAAm), acrylic acid (AA) and at least one hydrophobic monomer.

A method for at least partial deacetylation of a biopolymer comprising acetyl groups, including: a1) providing a biopolymer including acetyl groups; a2) reacting the biopolymer including acetyl groups with hydroxylamine (NH.sub.2OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated biopolymer; and a3) recovering the at least partially deacetylated biopolymer.

The present application relates to a freeze-dried polymer composition containing chitosan and at least one lyoprotectant, a process for preparing a freeze-dried composition containing chitosan and at least one lyoprotectant and the use of a reconstituted freeze-dried chitosan composition to prepare implants for tissue repair.