Cm. Agrawal et al., Effects of fluid flow on the in vitro degradation kinetics of biodegradable scaffolds for tissue engineering, BIOMATERIAL, 21(23), 2000, pp. 2443-2452
Scaffolds fabricated from biodegradable polymers are used extensively in th
e field of tissue engineering. Many of these scaffolds are subjected to flu
id flow, either in vivo or in bioreactors ex vivo. The goal of this study w
as to examine the effects of fluid flow on the degradation characteristics
and kinetics of scaffolds in vitro. Scaffolds with different porosity and p
ermeability values were fabricated using a copolymer of polylactic acid and
polyglycolic acid. These scaffolds were subjected to degradation in phosph
ate buffered saline at 37 degrees C for up to 6 weeks under two test condit
ions: static and flow (250 mu l/min). The porosity of the scaffolds decreas
ed up to 2 weeks and then increased, while the elastic modulus first increa
sed and then decreased over the course of the study. The mass and molecular
weight of the scaffolds exhibited a steady decrease up to 6 weeks. The res
ults further indicated that lower the porosity and permeability of the scaf
folds, the faster their rate of degradation. Additionally, fluid flow decre
ased the degradation rate significantly. It is possible that the high rates
of degradation observed here were due to autocatalysis of the degradation
reaction by the acidic degradation products. (C) 2000 Elsevier Science Ltd.
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