Biomedical Engineering Reference
In-Depth Information
dominate initial cellular events, future works are expected to fol-
low on utilizing bone-specific biomolecules, such as growth factors
and bone morphogenetic proteins. Depending on the types of bio-
molecules, the coupling method should be selected appropriately to
maintain the biologicalactivity of the molecules.
14.4.2 Incorporation of Biomolecules
To secure biological stability and therapeutic effects, biomolecules
are often introduced within the nanofiber matrix. In this case,
however, electrospinning conditions, such as solvent type, should
be carefully considered in order not to degrade the therapeutic
agents. A range of biomolecules have been incorporated within
polymer nanofibers, including antibiotics, proteins, and genes. 48 , 49
Li et al . used silk and its blending with polyethylene oxide to
incorporate bone morphogetic protein (BMP-2). 48 The mesenchy-
mal stem cells were shown to have higher osteogenic differen-
tiation and calcification on the BMP-nanofiber matrix. Nie et al .
reported a gene delivery system of nanofibers, wherein BMP-2 plas-
mid DNA was incorporated into PLGA-hydroxyapatite composite
nanofibers. 49 Instead of mixing genes directly with the nanofiber
solution, DNA was preloaded within chitosan and then electrospun
withthecompositesolution.Tansfectione ciencywasenhancedon
the nanofiber containing DNA-chitosan with respect to the control
nanofibergroup.
To entrap biomolecules within the nanofiber, a core-shell struc-
ture nanofiber has often been suggested. A dual-syringe apparatus
is designed to separate the injection lines of two solutions either
Solution 2
Solution 1
+ Biomolecules
(Electrospun nanofiber)
(Electrospinning set up)
Figure 14.6. Electrospinning nozzle setup for preparing a core-shell
nanofiber structure. Biomolecules incorporated within core polymer 1 will
be released through the outershell of polymer 2.
 
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