Materials for tissue bioengineering must have a set of properties, such as biocompatibility when interacting with cells in vitro and in vivo, adhesion, proliferation and differentiation of cells in the material. One of the most important requirements for this kind of materials is satisfactory physical and mechanical characteristics that are not inferior to the actual regenerated tissue in a given area of the body. The strength of collagen and chitosan-based materials meet all the requirements when used as matrices for tissue engineering. Block copolymers based on fish collagen and chitosan were obtained 0via ultrasonic irradiation of a mixture of homopolymers. Under the influence of ultrasonic irradiation, two effects— mechanochemical and radical—contribute to the breaking of chains (degradation of macromolecules). As a result, macroradicals are formed that randomly combine with each other. If there are two homopolymers in a solution, then under the influence of ultrasound the chains of both polymers are broken, the resulting macroradicals of different natures recombine and a block copolymer is formed. Films based on the obtained block copolymers of chitosan and collagen are characterized by a tensile strength of up to 120 MPa and are biocompatible with hTert-BJ5ta fibroblast cells. The properties of the material can be controlled by changing the ratio of components, the time of ultrasonic treatment, the molecular weight characteristics of the original homopolymers and the introduction of plasticizers that have a positive effect on the properties of the matrix. The totality of the results obtained shows that compositions based on block copolymers are superior to films made from homopolymers and their mechanical mixtures in terms of mechanical properties, adhesion and proliferation of fibroblast cells. This work was supported by grant of the Russian Science Foundation (project No. 23-13-00342, https://rscf.ru/project/23-13-00342/)