In situ thiolated alginate hydrogel: Instant formation and its application in hemostasis

Abstract

An in situ formed hydrogel was synthesized by sodium alginate and cysteine methyl ester, which turned the sodium alginate into thiolated alginate (SA-SH). SA-SH can in situ formed into hydrogel (SA-SS-SA) with a large amount of water through covalent bond in less than 20 s. The structure characterization showed that the mechanism of SA-SH gelation was thiol-disulfide transformation. The rheology and cytotoxicity experiments of SA-SS-SA hydrogel were also investigated, which indicated that SA-SS-SA hydrogel had an appropriate mechanical strength as well as an excellent biocompatibility. The SA-SS-SA hydrogel would degrade under certain conditions after a few days and its mechanism was disulfide alkaline reduction. Finally, the hemostatic property of SA-SH was tested by rat tail amputation experiment. The time to hemostasis of rat reduced from 8.26 min to 3.24 min, which proved that SA-SH had an excellent hemostatic property.

Study of locust bean gum reinforced cyst-chitosan and oxidized dextran based semi-IPN cryogel dressing for hemostatic application

“…These two characteristic absorbance peaks confirmed the cysteine conjugation on a primary amino group of chitosan backbone. The lower field shift of absorbance peak from 1558 to 1518 cm −1 in modified chitosan confirmed the amide bond formation between the amine group of chitosan and carboxylic group of cysteine amino acid [37] , [38] . Ellman's reagent was used to quantify the conjugated cysteine molecules via sulfhydryl groups.…”

Biopolymer Aerogels and Foams: Chemistry, Properties, and Applications

“…Typical biopolymers for biomedical applications include cellulose, chitin/chitosan, alginate, starch, and pectin, and the most common modification strategies are esterification, selective oxidation (TEMPO or periodate), amidation, and copolymerization with vinyl or acrylic monomers . Examples include carboxymethyl cellulose, or oxidized alginate and chitosan hydrogels for drug delivery, thiolated alginate hydrogels for hemostasis, enzyme‐assisted chitosan and pectin–gelatin hydrogels for chronic wound management, and cellulose, acrylic acid grafted starch, and κ‐carrageenan hydrogels for tissue engineering and drug delivery …”

Biopolymer‐Aerogele und ‐Schäume: Chemie, Eigenschaften und Anwendungen

“…Typische Biopolymere für biomedizinische Anwendungen sind Cellulose, Chitin/Chitosan, Alginat, Stärke und Pectin, und die häufigsten Modifizierungsstrategien sind Veresterung, selektive Oxidation (TEMPO oder Periodat), Amidierung und Copolymerisation mit Vinyl‐ oder Acrylmonomeren . Beispiele dafür sind Carboxymethylcellulose, und oxidierte Alginat‐ und Chitosan‐Hydrogele für den Wirkstofftransport, thiolierte Alginat‐Hydrogele für die Hämostase, enzymunterstützte Chitosan‐ und Pectin‐Gelatine‐Hydrogele für die Versorgung chronischer Wunden und Hydrogele aus Cellulose, Acrylsäure‐gepfropfter Stärke und κ‐Carrageen zum Gewebe‐Engineering und für den Wirkstofftransport …”