Fig. 3.

Vasculature applications of coaxial printing. (A) Tubular vessels were created by extruding sodium alginate onto a rotating rod (upper), and then assembled into multiscale vasculature (lower). (B) Alternatively, by crosslinking within a glass tube and varying the viscosity of the core and sheath fluids (left), coiled-rope structures (upper right) were created to provide space for the lumen formation of endothelial cells (lower right). (C) Artificial bio-blood vessels (BBV) were created using a sacrificial core fluid (left), showing enhanced limb salvage in a mouse model when laden with cells (EBBV) and statin drug (EABBV) (center right). (D) Coaxially printed vessels (left) showed better cell differentiation in vitro (center). They also significantly improved muscle-endothelial integration and blood vessel regeneration in a rat model, as compared to single fluid printing (right). Scale bars: (A) 5 mm; (B) 200 μm; (D) 200 μm. Reprinted (adapted) with permission from (A) Q. Gao et al., “3D Bioprinting of Vessel-like Structures with Multilevel Fluidic Channels,” ACS Biomater. Sci. Eng., vol. 3, no. 3, pp. 399–408, Mar. 2017, https://doi.org/10.1021/acsbiomaterials.6b00643. Copyright 2017 American Chemical Society. [61]; (B) [50]; (C) [43] and (D) [128].