Biomedical Engineering Reference
In-Depth Information
biocompatibilityandstrongmechanicalproperties,naturalandsyn-
thetic polymers were combined. These reinforced scaffolds were
composed of Vicryl (Polyglactin) and collagen sponges or films.
Many researchers utilized these reinforced scaffolds to repair uri-
nary tract defects as well as bladder and kidney surfaces. These
reinforced composite scaffolds were shown to be biodegradable,
prevent the leakage of urine, and to be readily replaced by collage-
nousscar tissue linedwith aurothelium.
9
−
12
Recently, a collagen sponge tube reinforced with copoly(L-
lactide/
ε
-caprolactone) was designed for urethral reconstruction.
The results of animal tests demonstrated that this reinforced scaf-
fold was slightly fibrotic but completely epithelialized and that it
supportedtheregenerationofsmoothmusclelayerswithoutfistulae
or stenoses.
13
Furthermore,reinforcedscaffoldshavebeenusedforhard-tissue
regeneration. A collagen scaffold reinforced with chitin fibers was
designed,andcellproliferation
in vitro
andbonegrowth
in vivo
were
evaluated. The results of these tests indicated that the cell popula-
tion and bone growth were superior to that obtained when colla-
gen scaffolds without chitin fibers were used. Further, the results
of these studies suggested that the suppression of shrinkage of the
sponges in the presence of chitin fibers maintained the interspace,
resulting in increased cell migration and bone formation.
14
,
15
Afib-
rin scaffold reinforced with PGA fibers was also utilized for hard
tissue regeneration (Fig. 28.1).
16
Figure28.1.
ComparisonofUTS(a)andcomparisonofcompressiontests
(b) between the collagen sponge (sponge) and reinforced collagen sponge
(reinforced)aftercellculture.(Seo
et al
.,Biotechnol.BioprocessEng.,1998).
Abbreviation
: UTS, ultimate tensile strength.
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