METHOD FOR PRODUCING COMPOSITE BIOMATERIAL CHITOSAN/HYDROXYAPATITE Russian patent published in 2021 - IPC C08J5/00 C08J5/18 A61L27/12 A61K31/722 

FIELD: composite biomaterials.

SUBSTANCE: invention relates to the production of composite biomaterials based on a natural polymer of chitosan containing calcium phosphates, in particular hydroxyapatite, and can be used in the production of sorbents and membranes, coatings, as well as for biotechnological purposes to create functional biomaterials for medicine and veterinary medicine, in particular, used in bone tissue engineering. The method for producing a composite biomaterial chitosan/hydroxyapatite includes preparing a solution of chitosan in dilute acid, introducing a soluble calcium salt and alkali metal dihydrogen phosphate into the resulting solution in amounts that provide a Ca:P molar ratio in the reaction mixture equal to 1.67, then increasing the pH of the reaction mixture and obtaining calcium-phosphorus-containing sediment. In this case, a 1% solution of chitosan in 0.1 M hydrochloric acid is prepared. Chloride or nitrate is used as a soluble salt. Potassium dihydrogen phosphate is used as the alkali metal dihydrogen phosphate. To increase the pH of the reaction mixture, it is placed in an ammonia NH₃ atmosphere for 50-60 minutes with stirring until a pH~10 value is reached. The resulting precipitate in an unchanged state is transferred to a thermostated drying oven with a temperature of 95-105°C and kept for 10-12 hours until it is completely dried to obtain a composite material in the form of a film containing a calcium phosphate phase with a structure that differs from apatite, the conversion of which to apatite is carried out by treating the resulting film with 0.1M NaOH solution, then washed with deionized water and dried.

EFFECT: homogeneous increase in the pH value throughout the volume of the reaction mixture during the synthesis of a composite material and an improvement in the conditions for its formation, which provides an increase in the mechanical strength of the resulting material and simultaneously makes it possible to obtain composite materials for various fields of application with the same composition, but with different properties, having different crystal structures mineral component and chitosan.

3 cl, 3 dwg, 4 ex