METHOD FOR EVALUATING VIABILITY OF A TISSUE ENGINEERING STRUCTURE WHEN CLOSING A TRACHEAL CRITICAL DEFECT ON AN EXPERIMENTAL ANIMAL MODEL Russian patent published in 2020 - IPC A61B17/03 G09B23/28 A61K35/28 A61P11/00 A61B6/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to experimental surgery, and can be used to assess viability of a tissue engineering structure when closing a critical tracheal defect on an experimental animal model. Part of the tracheal wall of the experimental animal is excised between 2nd and 7th rings to form a critical tracheal wall defect of at least 2×4 mm, fixation of tissue engineering structure in defect area. At end of 3 months after fixation of the tissue engineering, the trachea is examined by the radial technique with construction of 3D-model for evaluation of a degree of constriction of the tracheal lumen. After 6 months post-mortal histological and immunohistochemical examination of the explanted tissue engineering structure is performed, diagnostic test results are used as following: percent of tracheal lumen narrowing in area of fixation of tissue engineering structure (F_z), at narrowing by 75 % and more are assigned 0 points, less than 75 % – 1 point; evaluation of epithelisation of internal surface of tissue engineering (S_e), with complete epithelisation – 1 point, with no epithelialization or partial epithelisation – 0 points; density of microvessels in a submucosal layer of a tissue engineering structure (B_c), with density of 0–25 mm^-2 is assigned 0 points, at 26–50 mm^-2 – 1 point, more than 50 mm^-2 – 2 points. Value L_cb corresponding to the product of points is calculated by formula: L_cb=F_z*S_e*B_c. In the case of the calculated value L_cb<1, the absence of viability of the tissue engineering structure is stated. At L_cb≥1 is concluded on viability of tissue engineering structure.

EFFECT: method provides obtaining reliable data on biological and physiological compatibility of tissue engineering structures based on matrices of different origin when the tracheal critical defect is closed on the model of the experimental animal by creating a reliable method for evaluating the viability of the tissue engineering structure when closing the critical airway defect, allowing to assess the biological and physiological compatibility of the tracheal implant.

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