Novel printing strategy for high fidelity extrusion-based bioprinted multi-material nested models

Recent advances in drug development and tissue engineering have emphasized the need for precise 3D-printed multilayered blood vessel biomodels. Although existing extrusion-based models integrate biomaterials and cells, they often lack geometric fidelity, limiting their practical use in tissue engineering. This study addresses a key constraint in the generation of multi-material cylindrical constructs by developing a new printing protocol to enhance trajectory generation for extrusion-based multi-material nested cylindrical model bioprinting process. To overcome this challenge, we have developed a Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) software capable of generating multi-material nested cylindrical models and their printing trajectory using an innovative printing protocol. The protocol strategically modifies the starting point of each layer and avoids collisions during fabrication. Furthermore, it optimizes the printing order to minimize tool changes and enables flexible adjustment of photopolymerization timing and pathing. We have tested this approach on three multi-material tissue models and compared the results with the models generated using the BIOCAD software (RegenHU). Findings demonstrate that our protocol significantly improves cylindrical structure integrity, minimizes printing collisions and reduces overall printing time. Comparative analysis confirms the superior printing fidelity of the tissue models printed using our method, validating its effectiveness for extrusion-based cylindrical bioprinting applications. This optimized trajectory-generation approach provides a robust framework for creating physiologically accurate in vitro vascular models, potentially accelerating drug discovery and reducing the reliance on animal experimentation in biomedical research.