METHOD OF PRODUCING 4D HEAT-SENSITIVE HYDROGEL BASED ON CHITOSAN Russian patent published in 2023 - IPC C08J3/02 A61K47/36 B33Y70/00 A61L27/52 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a 4D thermosensitive hydrogel based on chitosan, including the following steps: (1) at room temperature, weight chitosan, dissolve the chitosan in a solution of acetic acid, stir until the chitosan is completely dissolved to obtain a chitosan solution; use a 4D bioprinter to print a chitosan solution into a thermosensitive chitosan-based hydrogel with a pore size of 50–100 μm in accordance with specified printing parameters: hole spacing is 600 μm, layer height is 100 μm, layer temperature is -25°C, printing speed is 15 mm/s, nozzle diameter is 0.3 mm and productivity is 0.1 g/min; and lyophilize after solvent extraction to obtain lyophilized chitosan; (2) load ultrapure water andβ-sodium glycerophosphate in a container with a water bath at a temperature of 60–70°C; after dissolution of β-sodium glycerophosphate cool to room temperature to obtain an aqueous solution of β-sodium glycerophosphate; (3) prepare an aqueous solution of carboxymethyl chitosan with ultrapure water at room temperature, add drop by drop the aqueous solution of β-sodium glycerophosphate obtained at step (2) into an aqueous solution of carboxymethyl chitosan and thorough mix to obtain a mixture; and (4) cross-link the lyophilized chitosan obtained at step (1) with the mixture obtained at step (3) for 1–2 minutes to obtain a 4D thermosensitive chitosan-based hydrogel with a uniform pore size; and the concentrations of chitosan, carboxymethylchitosan andβ α-sodium glycerophosphate in the 4D thermosensitive chitosan-based hydrogel obtained at step (4) are 10–30 wt.%, 10–30 wt.% and 60–80 wt.%, respectively.

EFFECT: invention provides a thermosensitive chitosan-based hydrogel with a uniform pore size which can be used as a scaffold for limbal stem cell transplantation that improves the entrapment efficiency of limbal stem cells and promotes the restoration of alkali-burned corneal epithelium.

6 cl, 3 ex, 5 dwg