NANOTECHNOLOGY AND 3D BIOPRINTING FOR NEURAL TISSUE REGENERATION - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 316

FIGURE 14.11
Typical 3D bioprinting techniques: (A) laser-based writing of cells, (B) ink-jet based systems and
(C) extrusion-based deposition. Images are adopted from Ozbolat and Yu (2013) .
(C17.2), collagen, and fibrin gel together ( Lee et al., 2010 ). C17.2 cells embedded within the col-
lagen showed comparable viability (92.89 ± 2.32%) after printing with that of manually plated cells.
When C17.2 cells were printed 1 mm from border of VEGF- releasing fibrin gel, the cells tended to
migrate toward the fibrin gel. This work illustrates the capability of VEGF-containing fibrin gels for
sustained release. These findings help to illustrate the role of sustained growth factor delivery within a
3D bioprinted neural construct.
In addition to cellular-level investigations, some studies have investigated the capacity of bio-
printed grafts in recovering sensory and motor function. In a study published by Owens et al., a cel-
lular nerve graft containing analogous potential to an autologous graft was fabricated via bioprinting
( Owens et al., 2013 ). Mouse bone marrow stem cells and Schwann cells were shaped into cylindrical
units as bioink constituents and then printed layer-by-layer to form a neural graft ( Figure 14.12 ). In
vivo experiments demonstrated that the cellular nerve graft performed satisfactorily in recovering both
motor and sensory function. Clinically, cells used for fabricating the cellular graft would be harvested
from the patient thus preventing immunological rejection. With regards to defect size, bioprinting
allows for the fabrication of clinically relevant grafts and the present work confirmed the superiority
of a bioprinted graft when compared to an autologous graft, the current therapeutic “gold standard”
for nerve injuries.