CONSIDERATIONS ON THE STRUCTURE OF BIOMATERIALS FOR SOFT- AND HARD-TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 517

thecircular,cylinder-likecounterelectrode,whichwasrotatingat60
rpm. The fibrous material collected on the counterelectrode formed
a tubelikestructure (Fig. 26.3a,b,d,e).
Preparation for a complex of PLA and water-soluble elastin 26 : A
tubelikecomplexofPLAandwater-solubleelastinwasgenerated.In
brief, water-soluble elastin was added to deionized water. A water-
solublecross-linkingagentwasaddedtothesolutionandstirredfor
a few minutes at room temperature. Triethylamine was then added
to the solution and stirred for another few minutes. The mixture
waspouredintoacylindricaltemplatealreadyinstalledintothePLA
tube and left to stand for two days until a gel had formed. The gel
was then copiously rinsed with deionized water. Finally, a milky-
white cylindrical molded article, which was a complex between
the PLA tube and water-soluble elastin, was obtained. The com-
plex was sterilized by autoclaving for all subsequent experiments
(Fig. 26.3c,f).
Preparation of a three-layered electrospun tube: An artery is com-
posed of three layers: intima, media, and adventitia. The intima is
composed of endothelial cells and the ECM. The media is composed
ofsmoothmusclecellsandelastictissues.Theadventitiaismadeup
of fibroblasts and connective tissues. Since the anatomical structure
ofthethree-layeredarterymaybeimportanttosupportthemechan-
ical properties of the vessel, we tried to mimic the three-layered
architecture using electrospinning techniques.
An electrospun tube was fabricated as follows: First, a mix-
ture consisting of poly( D , L ,-lactide- co -glycolide) (PLGA; 50/50) and
poly( D , L -lactide- co -caprolactone) (PLCA; 76/24) was spun toward
the circular, cylinder-like counterelectrode, which was rotating at
60 rpm. The fibers were discharged in the air using a neutralization
apparatus during development of the tube. Since the speed for fiber
spinningwasreducedbyneutralization,thefiberslaydownsoftlyon
the counterelectrode and were rolled up to create the intima layer.
For the media layer, PLCA was spun in a similar manner to give an
elastic texture. Finally, a mixture of PLGA and PLCA were spun to
generate theoutermost layer (Fig. 26.5).