REINFORCED SCAFFOLD FOR TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 562

tissue-engineered scaffold should provide adequate mechanical
strength during the initial stage of repair and be composed of a
highly porous structure that provides an ideal environment for
the migration and proliferation of cells. Additionally, the scaffold
shouldbedesignedtowithstandhandlingandsuturingduringsur-
gical implantation.
28.1 Introduction
Although various types of biomaterials have been developed and
utilized for the repair of damaged tissue and organs, the biocom-
patibility of these materials is of major concern. 1 − 4 Synthetic bio-
materialssuchasPGAandpoly-L-lacticacid(PLLA)havecommonly
been used in clinical applications. Synthetic materials may afford
betterplasticityandcontrolledbiodegradationthangraftsprepared
from natural extracellular matrix (ECM) materials, but they are also
less biocompatible. However, natural ECM materials such as gelatin,
alginate, chitosan, hyaluronate, collagen, amniotic membrane, and
small intestine submucosa (SIS) 5 , 6 may be less suitable for use in
tissue repair in many instances because of their weaker mechanical
properties.Forexample,themechanicalpropertiesofPGAarebetter
thancollagen,butthebiocompatibilityofPGAisnotasgood.Specifi-
cally,PGAhasbeenshowntoincreasetheproliferationofTcellsand
subsequently induce an inflammatory reaction. 7 As a result, many
researchers have designed composite or reinforced scaffolds to
overcome these shortcomingsassociated withPGA.
The scaffold design for tissue regeneration is one of the key
technologies used in tissue engineering. Scaffolds should mimic the
structure and biological function of the ECM. Collagen sponges are
highly porous, with interconnected pore structures that enable the
effective infiltration of cells and supply of oxygen and nutrients
to the cells. However, a drawback associated with using a colla-
gen sponge as a scaffold for cell proliferation and differentiation is
its poor mechanical strength. To overcome this problem, attempts
have been made to reinforce or combine sponges with other
materials. 8
Early reinforced composite scaffolds were developed for use
in urological surgery in 1987. Because the scaffolds required