FABRICATION OF TISSUE ENGINEERING SCAFFOLDS BY ELECTROSPINNING TECHNIQUES - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 222

of different structures have demonstrated superior potential in a
number of different tissue engineering applications. This chapter
reviews some recent developments related to the electrospinning
technique, with a focus on the control of the structure and assem-
blyof nanofibers.
11.2 Electrospun Nanofibers
Electrospunultrafinefibersaregenerallycollectedasnonwovenand
randomly arranged structures because of the bending instabilities
associated with the electrically charged liquid jets of the electro-
spun solution. The morphology and diameter of elecrospun fibers
are dependent on a number of processing parameters, including a)
the intrinsic properties of the solution, such as the type of polymer,
polymer concentration, viscosity, elasticity, electrical conductivity,
and surface tension of the solvent; b) operational conditions, such
asthefeedingrateforthepolymersolution,tip-to-collectordistance,
andthestrengthoftheappliedelectricfield;c)thedesignofthespe-
cific electrospinning setup; and d) the humidity and temperature of
the surroundings. 12
Chang et al. investigated the effect of electrospinning para-
meters on the diameter and morphology of bioactive glass (BG)
nanofibers. 13 Figures 11.2a and 11.2b showed that the morphology
of BG fibers changed from beaded fibers to smooth fibers with an
increaseinthepoly(vinylpyrrolidone)(PVP)concentrationfrom0.1
Figure 11.2. SEM images of bioactive glass nanofibers that were electro-
spun from an ethanol solution containing: (A) 0.1 g/mL PVP, 0.5 mL/mL BG
sol,andnoP123;(B)0.2g/mLPVP,0.5mL/mLBGsol, andnoP123;(C)0.2
g/mL PVP, 0.27 g/mL P123, and 0.33 mL/mL BG sol.