BLOOD VESSEL REGENERATION - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 160

in terms of surface features is very important. If only a simple cylinder is needed, then all of the above
fabrication processes could be used; however, if complex overhangs or surface topologies are needed,
then methods such as stereolithography and extrusion-based printing will need to be used based upon
their ability to fabricate free standing structures. The desired resolution of the printing process might
also be an important parameter for more complex geometries. Table 7.1 shows typical resolutions for
the discussed printing techniques.

7.1.9.2 Applications to the Vascular System and Other Engineered Tissues
3D printing of the vascular system opens a wide range of applications to tissue engineering and regen-
erative medicine. As discussed previously, vascularization is a limiting factor in implant design and
success. Additionally, complex geometries native to the vascular system could not always be replicated
on the surgical table. As such, 3D printing of custom tailored implants could fulfill this need by provid-
ing surgeons a means to develop implants using off-the-shelf 3D imaging techniques such as CT and
MRI. From these scans, complex architecture scaffolds could be developed and printed to meet the
desired application and treat the underlying condition.
There are still challenges associated with these sorts of implants, ranging from cell source, cell vi-
ability, surface properties, mechanical properties, and a wide range of regulatory constraints that must
be overcome prior to the application of these technologies to therapeutic applications.

Table 7.1 Comparison of various printing technologies commonly utilized in vascular

applications

Technique Typical resolution Material References

Stereolithography 25 to 50 m m Hydrogels and polymers ( Sodian et al., 2002;

Sodian et al., 2005;
Billiet et al . , 2012 )

∼ 100 m m

Fused Deposition
Modeling

Polymers ( Zein et al., 2002;

Miller et al., 2012 )

Ink-jet Bioprinting 20 m m (picoliter droplets) Liquids and hydrogels ( Campbell and

Weiss, 2007;
Boland et al., 2006;
Cui and Boland, 2009a;
Cui et al., 2012;
Arai et al., 2011;
Nakamura et al., 2005 )

∼ 100 m m Extrusion Based

Bioprinting

Hydrogels (natural and
synthetic), polymers

( Marga et al., 2012;
Jakab et al., 2010 )

Laser Assisted Bioprinting 10 m m Hydrogels ( Barron et al., 2004;

Guillotin et al., 2010;
Koch et al., 2013;
Barron et al., 2005;
Gaebel et al., 2011;
Koch et al., 2012 )