Fig. 5.

Physical properties of the CNF/BC hydrogel. a Schematic representation of BC biosynthesized in CNF hydrogel with a culture medium. Cross-sectional FE-SEM images of CNF/BC tubes (b), multilayered BC at the surface region (c), and the compositing morphology of CNF and BC at the deeper region (d). Cellulose fibers at the surface region (e) and the deeper region (f) were observed by staining with Calcofluor white. Shear strain dependency of storage modulus G′ for CNF/BC hydrogels at different CNF contents from 0 to 1.5% (g) and calcium ion treatment (h). i Changes in storage modulus by CNF content and calcium ion treatment. j Representative tensile stress–strain curve of CNF/BC hydrogels at different CNF contents and calcium ion treatments. k Maximum tensile stress of CNF/BC hydrogels. l Tensile elastic modulus of CNF/BC hydrogels at 10% strain. The scale bars are 20 μm in b–f. Data are presented as mean ± s.d. (n = 3 in I, k, and l)