Hydrogels and Bioprinting in Bone Tissue Engineering: Creating Artificial Stem?Cell Niches for in Vitro Models
Advances in bioprinting have enabled the fabrication of complex tissue constructs with high speed and resolution. However, there remains significant structural and biological complexity within tissues that bioprinting is unable to recapitulate. Bone, for example, has a hierarchical organization ranging from the molecular to whole organ level. Current bioprinting techniques and the materials employed have imposed limits on the scale, speed, and resolution that can be achieved, rendering the technique unable to reproduce the structural hierarchies and cell–matrix interactions that are observed in bone. The shift towards biomimetic approaches in bone tissue engineering, where hydrogels provide biophysical and biochemical cues to encapsulated cells, is a promising approach to enhance the biological function and development of tissues for in vitro modelling. A major focus in bioprinting of bone tissue for in vitro modelling is creating the dynamic microenvironmental niches to support, stimulate, and direct the cellular processes for bone formation and remodeling. Hydrogels are ideal materials for imitating the extracellular matrix since they can be engineered to present various cues whilst allowing bioprinting. Here, we review recent advances in hydrogels and 3D bioprinting towards creating a microenvironmental niche that is conducive to tissue engineering of in vitro models of bone.This review focuses on hydrogels and 3D bioprinting in bone tissue engineering for development of in vitro models of bone. It highlights challenges in recapitulating the biological complexity seen in bone and how synergistic application of dynamic hydrogels and innovative bioprinting pipelines could address these challenges to achieve bone models.This article is protected by copyright. All rights reserved