Biofabrication of bacterial nanocellulose scaffolds with complex vascular structure.

Bacterial nanocellulose (BNC) has proven to be an effective hydrogel-like material for different tissue engineering applications due to its biocompatibility and good mechanical properties. However, as for all biomaterials, in vitro biosynthesis of large tissue constructs remains challenging due to insufficient oxygen and nutrient transport in engineered scaffold-cell matrices. In this study we designed, biofabricated and evaluated bacterial nanocellulose scaffolds with a complex vascular mimetic lumen structure. As a first step a method for creating straight channeled structures within a bacterial nanocellulose scaffold was developed and evaluated by culturing of Human Umbilical Vein Endothelial Cells (HUVECs). In a second step, more complex structures within the scaffolds were produced utilizing a 3D printer. A print mimicking a vascular tree acted as a sacrificial template to produce a network within the nanoporous bacterial nanocellulose scaffolds that could be lined with endothelial cells. In a last step, a method to produce large constructs with interconnected macro porosity and vascular like lumen structure was developed. In this process patient data from x-ray computed tomography scans was used to create a mold for casting a full-sized kidney construct. By showing that the 3D printing technology can be combined with BNC biosynthesis we hope to widen the opportunities of 3D printing, while also enabling the production of BNC scaffolds constructs with tailored vascular architectures and properties.