Preparation method for hydroxyethyl chitosan in-situ hydrogel

Abstract

The invention belongs to the technical field of biomedicines and particularly relates to a preparation method for hydroxyethyl chitosan in-situ hydrogel. The preparation method comprises the following steps of firstly, dissolving sodium periodate powder into deionized water to obtain an aqueous solution of the sodium periodate; secondly, stirring an aqueous solution of sodium alginate and the aqueous solution of the sodium periodate to form a mixed solution; after the mixed solution is enabled to perform an oxidizing reaction, adding ethylene glycol to end the reaction; carrying out suction filtration on the mixed solution, carrying out dehydration precipitation on the mixed solution with absolute ethyl alcohol, and then carrying out low-temperature vacuum drying to obtain an oxidized sodium alginate crude product; dissolving the oxidized sodium alginate crude product into an aqueous solution of oxidized sodium alginate crude product with distilled water; carrying out complete dialysis on the aqueous solution of oxidized sodium alginate crude product, centrifuging, taking supernate for freeze drying to obtain oxidized sodium alginate; finally, mixing hydroxyethyl chitosan with the oxidized sodium alginate, carrying out cross-linking reaction on the mixed solution by a double-linkage syringe, and then pushing the reacted product into a test tube to obtain the hydroxyethyl chitosan in-situ hydrogel. The hydroxyethyl chitosan in-situ hydrogel is used for quickly coating and transplanting. The preparation method is simple in preparation process, safe and reliable in principle and low in preparation cost; the hydroxyethyl chitosan in-situ hydrogel has the advantages of good quality, safety and sanitation in use, and environment friendliness in a treatment environment.

Description

Technical field: [0001] The invention belongs to the technical field of biomedicine, and in particular relates to a preparation method of hydroxyethyl chitosan in situ hydrogel. Background technique: [0002] The cornea is located in the outermost layer of the eyeball, and the probability of injury is extremely high, which can easily lead to scars of varying degrees and affect vision. There are many types of corneal injuries, among which chemical injuries are difficult to treat clinically, because chemical substances can cause serious damage to the structure of the eye. It leads to epithelial necrosis, shedding, keratoconjunctival melting and perforation, and symblephane, etc., and the prognosis is poor. At present, amniotic membrane transplantation or corneal transplantation is mainly used for clinical treatment, but the former often occurs amniotic membrane autolysis, and the latter faces donor shortage and immune Rejection of two major problems, so limbal stem cell transp...

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Problems solved by technology

However, limbal stem cell transplantation must rely on a safe and reliable carrier, which is the key link to determine the application effect of this technology. If the carrier is suitable, limbal stem cell transplantation will bring new gospel to patients with corneal injury; The most common carrier is amniotic membrane, because as a kind of basement membrane, it has components similar to cornea and conjunctiva, that is, type IV collagen fibers. However, after severe corneal injury such as alkali burn, the expression of collagenase in the tissue increases greatly, which easily leads to amniotic membrane Autolysis directly delays the repair process; therefore, even if the patient is transplanted many times, the effect is still unsatisfactory. Exploring a safe and effective carrier for corneal limbal stem cell transplantation has become a current research hotspot.

[0003] In the prior art, water-soluble hydroxyethyl chitosan (HECTS) is an important derivative of chitosan, which can be catalyzed by biological enzymes in organisms and slowly degrades into monosaccharides that are nontoxic to the human body. Similar to the components of the extracellular matrix, it supports the adhesion and growth of cells; at the same time, it can inhibit the growth of fibroblasts and reduce the expression level of transforming growth factor-β (TGF-β) on the wound surface, so it has anti-adhesion effects; sodium alginate (SA ) is a natural polyanionic polysaccharide extracted from seaweed. It has good gelation, biocompatibility, low toxicity and relatively low price. It is widely used in light industry, food, tissue engineering and medicine. SA has Polyanionic carboxyl groups can form ion-crosslinked hydrogels with divalent ions, and are often used as embedding and immobilization carriers for enzymes, proteins, drugs, and animal and plant cells, but because divalent ions are easily combined with ions in the surrounding medium Exchange occurs, leading to uncontrollable degradation of the gel

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