Fig. 4.

Rheological validation of CBVdECM bioink and 3D bioprinting of CBV constructs. (A) Viscosity of 1.5% BdECM and VdECM hydrogels exhibiting shear-thinning behavior. (B) The complex moduli of the cross-linked BdECM (abbreviated as “B”) and VdECM hydrogels (abbreviated as “V”) showed higher storage moduli than loss moduli. (C) Gelation kinetics of the BdECM and VdECM hydrogels from 4 to 37 °C. (D) Sol–gel behavior of the BdECM and VdECM hydrogels before and after cross-linking for 1 h at 37 °C. (E and F) Viscosity (E) and complex modulus (F) values of cross-linked, reinforced CBVdECM bioink (abbreviated as “rCBVdECM”). (G) Automatic one-step printing process of polyethylene vinyl acetate (PEVA) chambers and CBV constructs: (i) printing of the PEVA chamber, (ii) coaxial printing of CBV constructs, and (iii) luminal perfusion of CBV constructs. (H) Schematic illustration of the luminal perfusion process used to remove the core sacrificial material and obtain a hollow structure. (I) Visual validation of perfusable CBV constructs using fluorescent beads with different colors. (J) Controlling the construct diameters by changing the core/shell pneumatic pressure (scale bars: 500 μm). (K and L) Schematic representation of the structural printing versatility (K) and actual results (L) (straight and meandering lines). Data represent mean ± SEM. All experiments were performed in triplicate.