Biomedical Engineering Reference
In-Depth Information
to 0.2 g/mL. Addition of pluronic P123 (EO
20
-PO
70
-EO
20
) resulted
in a decrease in the diameter of the BG fibers (Fig. 11.2c). Cui
et al.
designedanorthogonalexperimentsystemtooptimizetheprocess-
ing parameters of electrospining, which resulted in fibers with dif-
ferent morphologies and diameters by the controlling of different
parameters.
14
Furthermore, the researchers found that the surface
wettabilityofthefibrousmatscouldbeinfluencedbythefiberdiam-
eters, bead size, and bead percentage.
15
Meanwhile, they also com-
pared drug release properties of electrospun fibers with different
diameters and found that fibers with larger diameters exhibited
a longer period of nearly zero-order drug release compared with
fibers withsmaller diameters.
16
Yarin
et al.
recently fabricated core-shell nanofibers by co-
electrospining two different polymer solutions through a spinneret
comprisingtwocoaxialcapillaries.
17
Yang
et al.
alsofabricatedcore-
shell structured, ultrafine electrospun fibers as carriers for thera-
peutic proteins by emulsion electrospinning. Both studies indicated
thatthecore-shellstructuredelectrospunfibersprotectedthestruc-
tural integrity of the encapsulated protein during incubation in the
medium.
18
Nanofiberswithhollowinteriorscouldalsobefabricated
usingtheco-electrospiningtechniquefornanofluidicsandhydrogen
storage.
19
By changing the compositions used for electrospinning, Chang
et al.
fabricated composite fibers of poly(butylenes succinate)
(PBSU)/wollastonite/apatite via electrospinning and the bio-
mimetic process (Fig. 11.3a). The fibrous structures of the com-
posite scaffolds could be adjusted by the amount of wollas-
tonite or the incubation time.
20
Cui
et al.
developed electro-
spun fibrous nanocomposites of hydroxyapatite (HA) and poly(DL-
lactide) (PDLLA) through
in situ
growth (Fig. 11.3b).
21
In another
study,gelatinwasgraftedonthePDLLAfibroussurfacetoinduceHA
deposition (Fig. 11.3c).
22
The nucleation and growth of HA crystals
on a fibrous template could be controlled by induction conditions.
These fibrous nanocomposites should have potential applications
suchascoatingsonmedicaldevices,scaffoldsfortissueengineering,
andfillersforfiber-enforcedcomposites.Inshort,themorphologyof
electrospun fibers can be flexibly controlled by the electrospinning
parameters to meet the requirements for different applications.
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