MODERN APPROACHES AND POSSIBILITIES OF APPLICATION OF 3D MODELING FOR TISSUE ENGINEERING AND BONE REGENERATION. LITERATURE REVIEW
Authors: Hlushchenko Victoria , Ivakhniuk Tatiana , Oleshko Tetiana , Berladir Khrystyna , Smiyanov Vladyslav , Oleshko Oleksandr 
Published: December 2023

In recent decades, polymers and biomaterials (polylactic acid (PLA), polycaprolactone (PCL) and hydroxyapatite (HA)) have created a real alternative in orthopedics, surgery, and cardiac surgery to traditional metals, thanks to the possibility of elimination after the implementation of their function. Progress in 3D design and the possibility of involving 3D printing technologies to create three-dimensional structures makes it possible to bring modern science to a higher quality level. Also, the presence of disadvantages inherent in metal scaffolds, such as discrepancy in mechanical properties, uncontrolled resorption, and lack of biological neutrality of foreign material about bone tissue, due to the possible development of several clinical complications, is the main problem of using degradable alloys in clinical conditions. To eliminate these problems, the following methods are used: the formation of a protective coating, post-cast processing or the development of new alloys, the use of hydroxyapatite instead of metal bases, and the use of 3D printing technologies.
Materials and methods. The author selected more than 50 scientific works from the world literature on the problems on techniques for tissue engineering: fused deposition modeling, 3D printing, 3D bio circuitry, stereolithography, and selective laser sintering.
Results. The development of individual materials that are capable of biodegrading polymers and are biocompatible, alone or in combination with mineral components, makes it possible to obtain materials for 3D printing with mechanical properties and chemical stability suitable for use in bone tissue regeneration. The mechanical properties of the combined scaffolds can be used in the trabecular bone because they correspond to the mechanical characteristics of the latter. The ability to control degradation depends on the composition of the copolymer while demonstrating improvement as a result of the inclusion of mineral phases - hydroxyapatite. After all, HA enhances the degradation of copolymers based on PCl and PLA. The use of these materials during the production of three-dimensional structures by the method of direct 3D printing makes it possible to significantly reduce the consumption of resources and time. The possibility of correcting the framework architecture and porosity leads to the appearance of additional levers of balance and control in the direction of resorption of the nanomaterial, namely the possibility of creating artificial bone.
Conclusions. The data from processed literary sources and the results of a large number of studies allow us to state that the method of direct 3D printing is a priority in the production of three-dimensional porous structures, the basis of which can be natural (collagen, alginates, gelatin and chitosan) and synthetic polymers (aliphatic polyesters, polylactic acid (PLA), polyglycolic acid (PGA), poly-ε-caprolactone (PCL), polydioxanone (PDO)). At the same time, the latter, due to their properties, are more prioritized.