Proliferation of pig iliac endothelium cells (PIECs) on coverslips, bacterial nanocellulose (BNC) tubes, BNC/poly(vinyl alcohol) (PVA) composite tubes and PVA tubes at 1, 3, 5, and 7 days after cell seeding. Significant variance between groups is shown by asterisks (* p < 0.05). The tubes processed from the first bioreactor which was assembled with an about 60 mm silicone tube (inner diameter × external diameter: 2 × 3 mm) and a glass tube (8 × 10 mm), were defined as S-BNC tubes. The other bioreactor was consisted of two silicone tubes with various calibers (2 × 3 mm, 8 × 9 mm), were defined as D-BNC tubes. Reproduced with permission from [74]. Royal Society of Chemistry, 2015.