CHITOSAN APPLICATION METHOD AND CHITOSAN COATED ANTIMIGRATION STENT-ENDOPROSTHESIS Russian patent published in 2020 - IPC A61L27/20 A61L31/10 A61F2/90 A61F2/966 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to a method for applying biopolymer coating from chitosan, preventing ingrowth of stent-endoprosthesis into walls of hollow organ and device with biopolymer coating for introduction into hollow organs to increase their lumen, in particular, to antimigration stent-endoprosthesis. Method of applying a chitosan coating on an antimigration stent-endoprosthesis is characterized by dissolving chitosan in an acid, immersing the stent into the obtained solution, fixing the obtained coating and drying. Method comprises preparing 5 wt% solution of chitosan in 5 % aqueous solution of citric acid, stents-endoprosthesis are placed on a holder frame, made with possibility of rotation around its axis of symmetry, frame of holder with stents is lowered into solution of chitosan in acid and rotating frame is maintained in obtained solution for 3 minutes. Then the frame is immersed in 10 % water solution of triethanolamine for 5 minutes, dehydrated by immersion into pre-cooled ethanol with supersaturated sodium hydroxide for 30 minutes, and dried in vacuum for 1 hour until complete evaporation of solvent. Antimigratic stent-endoprosthesis for hollow organs is made of alloy with shape memory, with possibility of change of configuration when hollow organ is introduced into cavity. Stent-endoprosthesis contains the sections made with possibility of their opposite unwinding. Stent-endoprosthesis is made in the form of a hollow mesh cylinder formed by an interlacing of wire from alloy with memory of the form and consists of alternating belts of a grid of two types: belt of the first type, consisting of one row of compressed wire grid cells, uniformly expanding when heated in transverse direction, belt of the second type, consisting of one row of mesh squeezed in compressed condition of wire mesh, swirled relative to longitudinal stent axis and untwisted at heating in place of installation. Each next belt of wire cells of the grid of the second type is twisted oppositely in relation to the previous belt of the second type, which realizes possibility of opposite shift movements of belts of the first type relative to each other at expansion of stent in the place of installation. Stent-endoprosthesis is coated with chitosan by the method described above.

EFFECT: wider range of hollow organs recovery means, as well as a range of methods for applying biocompatible polymer materials on nitinol, for example, chitosan.

2 cl, 4 dwg