STRATEGIES TO ENGINEER ELECTROSPUN SCAFFOLD ARCHITECTURE AND FUNCTION - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 299

biomaterial scaffolds, presumably because of the better availability
ofoxygenandnutrients.Consequently,implicitinanyeffectivestrat-
egy to increase cell infiltration into electrospun meshes is a method
to keep them there. Perfusion culture may be one such method, as
it has been shown to maintain uniform cell distributions in macro-
porous scaffolds 44 , 45 and improve cell distribution in electrospun
scaffolds. 39
15.3.5 Electrospraying or Electrospinning of Cells
As an alternative to porogens and other methods to increase
the pore size of electrospun meshes and facilitate migration of
mammalian cells into electrospun scaffolds, methods have been
developed to incorporate live cells into scaffolds during the elec-
trospinning process. Stankus et al. have used both pressurized air
to spray suspensions of cells 46 and voltage potentials of 8.5 to
10 kV to electrospray suspensions of cells (in a conventional cul-
ture medium) 46 , 47 during the electrospinning process. Despite the
toxicity of the solvent used to electrospin their polymer (hexaflu-
oroisopropanol in this case), Stankus et al. showed good distri-
butions of cells throughout the scaffolds as well as evidence of
cell proliferation within the scaffolds. Recently, van Aalst et al. 48
tested an alternative approach in which cells were electrospun
from a poly(vinyl alcohol) (PVA) solution in such a way that
they were embedded within electrospun PVA filaments. The cells
were subsequently released by dissolution of the water-soluble
PVA.
15.4 Creation of Three-Dimensional Architectures for
Tissue-Specific Applications
Electrospun scaffolds must be processed into an appropriate three-
dimensionalformforeachtissueengineeringapplications(i.e.bone,
tendon/ligament, and cardiovascular). These three-dimensional
structures can be intrinsically complex, but relatively simple archi-
tectures have been described that are suitable for cardiovascular,
peripheral nerve, and connectivetissue applications.