SOLID FREEFORM FABRICATION METHOD APPLIED TO TISSUE SCAFFOLDS - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 616

Figure 31.8. SEM image of a fabricated chitosan/gelatin structure. 23

fabricate a master pattern for the 2D Polydimethylsiloxane (PDMS)
mold. Chitosan/gelatin material was cast and freeze-dried on the
mold, resulting in a 2D shape composed of natural polymer. A 3D
structure was then created by assembling the 2D layers (Fig. 31.8).
Cell culture results using hepatocytes were also presented.
In contrast, Schuster et al . developed a solublephotopolymer for
use in SL that had high photoreactivity and mechanical strength 19
andcouldberemovedbyanalkalisolution.Abiocompatiblecopoly-
mer was molded using the developed resin. M. Vallet-Regi used
the etching properties of a commercialized photopolymer 20 , 21 ;a3D
mold was fabricated using Accrura SI10 from 3-D Systems, Inc., and
a biomaterial was injected. The mold was then etched using a 2 M
NaOH solution. Kang et al . studied the molding process for vari-
ous biomaterials, such as poly-

ε

-caprolactone (PCL), bone cement,
and poly(lactic-co-glycolic) acid (PLGA), for tissue engineering. The
soluble photopolymers proposed by Schuster 19 and high-resolution
MSTL technologies 22 were used to fabricate 3D scaffolds, and the
lost-mold shape-forming process was exploited using various bio-
materials (Fig. 31.9). 24 , 25

31.2.2 Fused Deposition Modeling
FDM is an SFF process commonly used in mechanical system design
and manufacture. The technology was developed by S. S. Crump
in the late 1980s and was successfully commercialized in 1990. A
traditional FDM machine consists of a head-heated liquefier