BIOMATERIALS AND MANUFACTURING METHODS FOR SCAFFOLD IN REGENERATIVE MEDICINE - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 21

phosphate/methylhydroxypropylcellulose composite for bone
regeneration materials, a polyethylene oxide- co -polybutylene
terephthalate for bone bonding, poly( ortho -ester) and its compos-
iteswithceramicsfortissue-engineeredbone,synthesizedconduct-
ing polymer polypyrrole/hyaruronic acid composite films for the
stimulation of nerve regeneration, and peptide-modified synthetic
polymers for the stimulation ofcell and tissue. 1 , 5 , 7
It is very important for the design and synthesis of more
biodegradable and biocompatible scaffold biomaterials to mimic
the natural ECM in terms of bioactivity, mechanical properties,
and structures. The more biocompatible biomaterials tend to elicit
less of an immune response and to reduce inflammatory response
at the implantation site, combined with scaffold-manufacturing
methods. 13
1.2.4 Natural Polymers
Many naturally occurring scaffolds can be observed as biomaterials
for regenerative medicine and tissue engineering purposes. One of
the typical examples is the ECM that is a very complex biomater-
ial and controls cell function. For the ECM of regenerative medicine
and tissue engineering, natural and synthetic scaffolds are designed
to mimic specific functions. Natural polymers are fibrins, collagens
(gelatin), alginate, proteins, albumin, gluten, elastin, fibroin, hyaru-
lonic acid, cellulose, starch, chitosan (chitin), sclerolucan, elsinan,
pectin (pectinic acid), galactan, curdlan, gellan, levan, emulsan, dex-
tran, pullulan, heparin, silk, chondroitin 6-sulfate, polyhydroxyalka-
noates, etc. (Chemical structures are shown in Fig. 1.2C.) Much of
the interest in these natural polymers comes from their biocompat-
ibility, relatively abundance and commercial availability, and ease of
processing. 16
1.2.4.1 Fibrin
Fibrin plays a major role during wound healing, such as forming
a hemostatic barrier to prevent bleeding and to support a natural
scaffold for fibroblasts. The actual polymerization is triggered by