Fig. 2. SEM photomicrographs cross-section of a gelatin nano-non-woven.
Magnification 300x (left) and 1000x (right)
On the other hand, polymeric nano-non-wovens obtained by electrospinning
are characterized with strictly controlled morphology of pores, which
depends on the material or the solvent used for the spinning and other
parameters of the process (Fig. 2). From a large selection of available
materials, one could choose materials that can be then easily removed
from the obtained scaffolds. Such nano-non-wovens were regarded as
non-classic pore precursors that enable for obtaining the structures of
desired morphology (defined by nano-non-woven). Their additional
advantage, in comparison to conventional precursors, is the formation of
pores in the entire volume of the scaffold. It guarantees the formation
of pores that are evenly distributed, not only inside the scaffold but
also on one of the surfaces.
In the next stage of the study, poly-L-lactide scaffolds have been
prepared using a gelatin nano-non-woven as a non-classic pore precursor.
Also, a combination of a gelatin nano-non-woven and classic pore
precursors was used (PVP or PVP and Pluronic®). Analogical tests were
conducted for other polyesters (PCLA and PCL).
A small number of pores having a diameter of about 5 µm was observed on
the bottom surface of the scaffold obtained from poly-L-lactide using a
gelatin nano-non-woven (Fig. 3). On the other hand, numerous irregular
pores of the size of 20–50 µm could be seen on the upper surface. Here,
”imprints” of nanofiber were also observed, application, pressing and
washing out of which have destroyed the thin covering layer. In the
cross-section of the scaffold, there were irregular and mutually linked
pores 20–80 µm in size. Their 2–5 µm thick walls contained oval pores
of a size of 1–2 µm. Also, walls of the pores, similarly to those at
the upper surface, contained ”imprints” of nanofiber which proves the
efficiency of using the non-wovens. In the scaffolds obtained with the
nano-non-wovens, the ”imprints” of gelatin nanofibers were observed.