Method for the production of hydrogel comprising chitosan and negatively charged polyelectrolytes, and cellular, porous material resulting from said hydrogel

A method of producing a hydrogel, comprising the following steps in succession:

• a first step (i) of providing at least one powder of an anionic polymer (A) and at least one chitosan powder (B) comprising amine functions (—NH2);
• a second step (ii) of dry mixing at least the powders (A) and (B) from the first step in order to form a mixture of powders, wherein the powders (A) and (B) are intimately mixed;
• a third step (iii) of suspending the mixture of powders obtained from the second step in an aqueous medium having a pH that can enable the anionic polymer (A) to be dissolved without dissolving the chitosan (B);
• and
• a fourth step (iv) of adding an acid to the suspension obtained from the third step in order to form the hydrogel;
• wherein the hydrogel is a moldable material and configured to be a self-sustaining shape,
• wherein the degree of deacetylation of the chitosan (B) is higher than or equal to 60% and lower than or equal to 85%,
• wherein the ratio of the weight of the at least one chitosan powder (B) relative to the total weight of the hydrogel is higher than or equal to 1%,
• wherein the ratio of the weight of the at least one anionic polymer powder (A) relative to the total weight of the hydrogel is higher than or equal to 1%, and
• wherein the ratio of the weight of the chitosan powder (B) to the weight of the anionic polymer powder (A) (w/w) is from 0.6 to 1.4.