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International Journal of Bioprinting Biomaterials for vascularized and innervated tissue regeneration

Figure 5. Schematic representation of design and fabrication of 3D-printed chips. First: biomaterials synthesis and chip engineering. Second: smart
delivery of biological factors and electrical signal cues to wound beds can stimulate the neural differentiation of MSCs and excitation function recovery .
[92]
Reprinted from Peng L H, Xu X H, Huang Y F, et al., Advanced Functional Materials, 2020, 30: 2001751. Copyright © 2020 John Wiley and Sons.
the complex hierarchical structure, organic–inorganic 3D printing technique (Figure 6A) [108] . Compared to
components, and physiological properties of bone traditional 3D-printed scaffolds stacked by solid structs,
tissues [100] . For example, 3D-printed bone regenerative the multichannel structs were capable to enhance oxygen/
scaffolds with multi-channel structures could promote nutrients transports and promote the early angiogenesis
host cells infiltration and serve as cell delivery platforms inside the implanted scaffolds. The in vivo results further
for new tissue regeneration [101] . Besides, integrating confirmed the satisfactory effects of channel structures
bioactive factors into 3D-printed scaffolds could mimic on vascularization. Similarly, Hann et al. prepared
the microenvironments in bone formation, then accelerate perfusable vascular networks-based biomimetic bone
the process of bone repair [102,103] . Moreover, 3D bioprinting scaffolds by combining stereolithography (SLA) and fused
has brought promise to prepare biomimetic bone deposition modeling (FDM) 3D printing technology [109] .
constructs with precise distribution of multiple cells [104-106] . The perfusable channels can provide appropriate
Biomimetic 3D cell-laden construct could highly mimic microenvironments for vasculogenesis and angiogenesis.
the hierarchical structure and cellular components of In order to enhance the tissue regeneration capacity inside
native bone tissues, enabling rapid integration with host the hollow-channel structs of the 3D-printed scaffolds,
systems and accelerated healing rate. Wang et al. developed a smart scaffold with hollow-pipe
channel structures and stimuli-responsive features by
4.2. 3D-printed biomaterials for vascularized bone using microfluidic 3D printing technique (Figure 6B) [110] .
regeneration The channel dimensions showed reversible swelling and
Bone scaffolds with macroporous or channel structures shrinkage properties under near-infrared light irradiation,
are beneficial to the penetration of cells and ingrowth which is beneficial to the infiltration of external cells into
of host blood vessels. It is well known that 3D printing hollow channels. As a result, these near-infrared-responsive
technology could easily control the structure of scaffolds channels could obviously promote the deep infiltration of
from macroscale to microscale [107] . For example, our group host vessel into scaffolds and effectively accelerate bone
developed lotus-like biomimetic scaffolds via a modified regeneration in vivo.

Volume 9 Issue 3 (2023) 223 https://doi.org/10.18063/ijb.706