Potential of PVA-doped bacterial nano-cellulose tubular composites for artificial blood vessels

Bacterial nano-cellulose (BNC) hydrogel has been suggested as a promising biomaterial for artificial blood vessels. However, some properties of BNC do not achieve all of the requirements of a native blood vessel - compliance, for instance. In order to improve the properties of BNC tubes, poly(vinyl alcohol) (PVA) was introduced in the BNC tubes to make composites. Two types of pristine BNC tubes with different inner structures were produced in two bioreactors. A PVA tube and PVA-BNC tubular composites were made for comparison by using a thermally-induced phase separation method. The morphology, water permeability, cytotoxicity, and mechanical properties, including the axial stretch strength, suture retention, burst pressure, and compliance of all the tubes, were evaluated and compared. The results indicated that PVA impregnated into BNC tubes and then significantly improved the properties of BNC, especially the mechanical properties and water permeability. The BNC tube itself played a great role in the performances of the composites as the skeleton base material. The PVA-BNC composite tubes could constitute new biomaterial candidates for vascular grafts.