Development of Extrusion-Based 3D Printing Technology for Hydrogel Shape-Morphing Scaffolds and Simulation of Their Spatial Deformation

Additive manufacturing makes it possible to create objects with complex geometry for various applications, including personalized implants. Hydrogel scaffolds with shape-morphing effects are of particular interest in the field of soft tissue engineering. This work describes the technology of extrusion-based 3D printing of objects of complex spatial shape based on biopolymer viscous ink. A technique for producing viscous ink based on sodium alginate, hydroxypropylmethylcellulose and silver nanoparticles embedded in a polymer matrix has been developed. The sizes of silver nanoparticles were determined via dynamic light scattering. The colloidal stability of silver nanoparticles was assessed by analyzing the peak of surface plasmon resonance using UV-VIS spectroscopy. The compliance of the developed viscous ink with the requirements for materials for extrusion-based 3D printing was confirmed by the results of comprehensive rheological research. The main patterns of the relationship between the infill pattern parameters during 3D printing and the degree of deformation of hydrogel structures resulting from anisotropic swelling of sections of various thicknesses have been identified. The developed Alg3/HPMC3/AgNPs scaffolds exhibited preliminary cytocompatibility and supported cell viability. The deformation of hydrogel structures was modeled using finite element analysis, which enables the prediction of their spatial shape for further design of personalized cartilage implants.