132
spatial arrangements of the printed cells. They also reported a high viability in the
printed HUVECs containing microchannels. Using similar laser bioprinting techniques, Wu et al. developed a branched vascular microenvironment (~50–100 um
in caliber) with HUVECs and human umbilical vein smooth muscle cells
(HUVSMCs) [50]. The group first printed a structure with HUVECs, which was
incubated for a day before the scaffold was removed. HUVSMCs were then printed
on top of this structure, creating a combined microvasculature environment. In this
study, the development of self-formed network lumens was dependent on the laserprinted lumen, demonstrating the potential for using 3D laser bioprinting to make
a stable vasculature network. Though the exact ratio of HUVECs and HUVSMCs
was not quantified, proliferation and differentiation patterns in the vascular construct demonstrated that there was high printed cell viability and robust cell-cell
interactions.
More recently, a microscale capillary-like vascular network was developed by
Zhu et al. using LGDW printing with a bioink composed of HUVECs and mouse
fibroblasts encapsulated in GelMA and GM-HA [56]. Cell viability of the printed
vascular tissues was over 85%, and pericyte phenotype induction by the mouse
fibroblasts facilitated endothelial network formation by the HUVECs. To investigate endothelial network formation in vivo and anastomosis formation with the host
vessels, the vascularized capillary network was implanted subcutaneously into a
mouse model. The capillary network was observed to be dense 2 weeks after the
surgery, and successful anastomoses between the printed vascular network and the
host vasculature were demonstrated. This study demonstrated the potential for complex vascular biofabrication using laser 3D printing technology.
Vascular Graft Creation (Table 5.2)
3D laser bioprinting has also been used to fabricate larger-caliber vascular tissues.
For instance, Baudis et al. used digital light photopolymerization (DLP) techniques
to construct large-scale vascular tissue [1]. They developed a bioink formulation
composed of photoelastomers made from cross-linked monoacrylate (MA) and
dicarylate (DA), dithiol-based chain transfer agent (CTA), and a reactive diluent,
designed to optimize the mechanical properties and geometry of the printed vascular constructs. The printed vessels were demonstrated to have mechanical properties
comparable to native blood vessels. The DLP technique, which involved irradiation
of a photosensitive resin, allowed for fabrication of vascular constructs with very
precise dimensions (~1 mm in caliber). The photosensitive resin enabled the formation of a reversible crosslink in the printed tissue. These cross-links conferred
mechanical properties that mimic those of the native porcine coronary artery, in
terms of suture tear resistance, tensile strength, and fracture strain.
The use of photosensitive resin was further investigated by Wolfdietrich Meyer
et al. for the fabrication of bifurcated large-diameter, native-like tubular systems
(diameter ~2 mm) [36]. The study employed a series of photosensitive oligomerE. Yeung et al.
spatial arrangements of the printed cells. They also reported a high viability in the
printed HUVECs containing microchannels. Using similar laser bioprinting techniques, Wu et al. developed a branched vascular microenvironment (~50–100 um
in caliber) with HUVECs and human umbilical vein smooth muscle cells
(HUVSMCs) [50]. The group first printed a structure with HUVECs, which was
incubated for a day before the scaffold was removed. HUVSMCs were then printed
on top of this structure, creating a combined microvasculature environment. In this
study, the development of self-formed network lumens was dependent on the laserprinted lumen, demonstrating the potential for using 3D laser bioprinting to make
a stable vasculature network. Though the exact ratio of HUVECs and HUVSMCs
was not quantified, proliferation and differentiation patterns in the vascular construct demonstrated that there was high printed cell viability and robust cell-cell
interactions.
More recently, a microscale capillary-like vascular network was developed by
Zhu et al. using LGDW printing with a bioink composed of HUVECs and mouse
fibroblasts encapsulated in GelMA and GM-HA [56]. Cell viability of the printed
vascular tissues was over 85%, and pericyte phenotype induction by the mouse
fibroblasts facilitated endothelial network formation by the HUVECs. To investigate endothelial network formation in vivo and anastomosis formation with the host
vessels, the vascularized capillary network was implanted subcutaneously into a
mouse model. The capillary network was observed to be dense 2 weeks after the
surgery, and successful anastomoses between the printed vascular network and the
host vasculature were demonstrated. This study demonstrated the potential for complex vascular biofabrication using laser 3D printing technology.
Vascular Graft Creation (Table 5.2)
3D laser bioprinting has also been used to fabricate larger-caliber vascular tissues.
For instance, Baudis et al. used digital light photopolymerization (DLP) techniques
to construct large-scale vascular tissue [1]. They developed a bioink formulation
composed of photoelastomers made from cross-linked monoacrylate (MA) and
dicarylate (DA), dithiol-based chain transfer agent (CTA), and a reactive diluent,
designed to optimize the mechanical properties and geometry of the printed vascular constructs. The printed vessels were demonstrated to have mechanical properties
comparable to native blood vessels. The DLP technique, which involved irradiation
of a photosensitive resin, allowed for fabrication of vascular constructs with very
precise dimensions (~1 mm in caliber). The photosensitive resin enabled the formation of a reversible crosslink in the printed tissue. These cross-links conferred
mechanical properties that mimic those of the native porcine coronary artery, in
terms of suture tear resistance, tensile strength, and fracture strain.
The use of photosensitive resin was further investigated by Wolfdietrich Meyer
et al. for the fabrication of bifurcated large-diameter, native-like tubular systems
(diameter ~2 mm) [36]. The study employed a series of photosensitive oligomerE. Yeung et al.