Template-Assisted Electrospinning and 3D Printing of Multilayered Hierarchical Vascular Grafts.

Fabricating complex hierarchical structures mimicking natural vessels and arteries is pivotal for addressing problems of cardiovascular diseases. Various fabrication strategies have been explored to achieve this goal, each contributing unique advantages and challenges to the development of functional vascular grafts. In this study, a three-layered tubular structure resembling vascular grafts was fabricated using biocompatible and biodegradable copolymers of poly(butylene succinate) (PBS) using advanced manufacturing techniques. The outer layer was fabricated by template-assisted electrospinning utilizing a 3D-printed scaffold with a precise hexagonal pore design as the template, and the inner layer was coated with gelatin through perfusion. Cellulose nanocrystals (CNCs) were incorporated into electrospun fibers to enhance mechanical properties. The gelatin coating was applied to the lumen using perfusion coating, resembling the inner layer. Integration of 3D-printed structures with electrospun fibers via template-assisted electrospinning and gelatin coating resulted in a seamless multilayered scaffold. Mechanical testing demonstrated robustness, surpassing natural arteries in some aspects, while the gelatin coating significantly reduced liquid leakage, ensuring leak-free functionality. Cytotoxicity assessment confirmed the biocompatibility of processed materials with fibroblast cells, supporting potential for medical applications.