An Overview of Hydrogel‑Based Bioinks for 3D Bioprinting of Soft Tissues

Abstract

It has been widely perceived that three-dimensional bioprinted
synthetic tissues and organ can be a clinical treatment option
for damaged or diseased tissue repair and replacement. Conventional
tissue engineering approaches have limited control over the regeneration
of scaffold geometries and cell distribution. With the advancement of
new biomaterials and additive manufacturing techniques, it is possible to
develop physiologically relevant functional tissues or organs with living
cells, bioactive molecules and growth factors within predefined complex
3D geometries. In this perspective, this review discusses how hydrogel-
based bioinks can be used to mimic native tissue-like extracellular
matrix environment, with optimal mechanical and structural integrity for
patient-specific tissue regeneration, in reference to advanced bioprinting
technologies to bioprint multitude of multicomponent bioinks. This
review also summarizes various bioprinting techniques, the gelation and
biodegradation mechanisms of hydrogel-based bioinks, the properties
required for ideal bioink, challenges to design bioinks, as well as reviews
the fabrication of 3D printed cardiac tissue, cartilages, brain-like tissue,
bionic ear, and urinary system.