Microvasculature
functions at the tissue and cell level, regulating
local mass exchange of oxygen and nutrient-rich blood. While there
has been considerable success in the biofabrication of large- and
small-vessel replacements, functional microvasculature has been particularly
challenging to engineer due to its size and complexity. Recently,
three-dimensional bioprinting has expanded the possibilities of fabricating
sophisticated microvascular systems by enabling precise spatiotemporal
placement of cells and biomaterials based on computer-aided design.
However, there are still significant challenges facing the development
of printable biomaterials that promote robust formation and controlled
3D organization of microvascular networks. This review provides a
thorough examination and critical evaluation of contemporary biomaterials
and their specific roles in bioprinting microvasculature. We first
provide an overview of bioprinting methods and techniques that enable
the fabrication of microvessels. We then offer an in-depth critical
analysis on the use of hydrogel bioinks for printing microvascularized
constructs within the framework of current bioprinting modalities.
We end with a review of recent applications of bioprinted microvasculature
for disease modeling, drug testing, and tissue engineering, and conclude
with an outlook on the challenges facing the evolution of biomaterials
design for bioprinting microvasculature with physiological complexity.