Biomedical Engineering Reference
In-Depth Information
FIGURE 2.8
The group at the National University of Singapore designed and built a rapid prototyping (RP)
machine and software, which is specifi cally dedicated to scaffold fabrication. The machine is based on an
extrusion/dispenser head (multiple heads are also possible) by a three-axis robot (A). The process generates a
scaffold from a computer fi le (STL, etc.) by building microstrands or dots. Depending on the machine setup, a
tissue engineer can make use of a wide variety of polymer pastes/solutions (B, chitosan), and hot melts as well
as dispersions and chemical reactive systems (e.g., fi brin glue).
A
B
C
D
Scaffold
Scaffold
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FIGURE 2.9
(A) Two full-thickness critical bone defects (5-mm diameter) were created in the rat parietal
bone. Bone chips are shown. (B) Implantation of PCL/TCP-Col1 scaffolds into the defects (Inset: PCL-TCP
scaffold (5-mm diameter and 1-mm thick, 0-900 lay-down pattern, 70% porosity) before treatment,
left
, and
after lyophilization of 350 µg of rat tail collagen 1,
right
. (C,D) Micro-CT scanning of the skull defect show-
ing the bone formation 13 months with and without scaffold implantation. It can be seen in (D) that there is
formation of new bone, made possible by the implantation of the PCL/TCP/Col scaffold, which were produced
via FDM.
