4. By employing these optimized parameters, scaffolds composed
by different numbers of layers (ranging from 12 to 64) have
been produced.
5. When chloroform is used as solvent (e.g., in the case of
PHBHHx scaffold fabrication), a glass syringe should be used.
6. Be sure that no air bubbles are present in the syringe in order to
have a better control over polymeric solution flow rate during
scaffold fabrication. An effective way to place the solution
inside the syringe is removing the plunger and mounting a
Luer stop cap on the syringe in order to avoid the solution
flowing out. After the solution is poured into the syringe under
a fume hood, insert only partially the plunger, remove the Luer
stop cap, and eliminate the air inside the syringe by pushing
gently on the plunger. Finally mount the blunt tip needle on
the syringe.
7. Be sure that no solidified polymer is formed where the solution
can come in contact with air (e.g., at the tip of the syringe
before coupling it to the blunt tip needle or at the tip of the
needle while fixing the syringe to the pump due to an accidental
pressure on the plunger) in order to not compromise the feed
rate control. In case of polymer solution leaking during syringe
mounting on the pump, clean the needle tip accurately with
solvent-soaked paper.
8. You can use bi-adhesive tape to fix the beaker to the construction platform. The use of a Pyrex glass beaker is recommended
to avoid sample detachment during fabrication. In the case of
polymers showing high shrinkage degree during coagulation,
warming the coagulation bath of few degrees Celsius (e.g., up
to 25/26
C) can be an effective way to avoid sample
detachment.
9. It is advised to do the coordinates zeroing before filling the
beaker with the non-solvent in order to have a better visual
control of the actual needle tip position.
10. In all fabrication processes reported in Table 2, ethanol was
employed as a low toxic non-solvent suitable for polymer coagulation; when water was tested as a non-solvent, a homogeneous solution filament was not formed.
11. Although the volumes of solvent and non-solvent employed
and evaporated during the process are low, it is recommended
to perform the fabrication process under a fume hood.
12. Before starting the fabrication of the first layer, keep the needle
tip at a distance from the bottom of the beaker in order to ease
the observation of the extruded filament (see Note 13).
13. After the pump is started, small bubbles exiting from the
needle tip should be seen due to air inside the needle. Since
108
Dario Puppi and Federica Chiellini
by different numbers of layers (ranging from 12 to 64) have
been produced.
5. When chloroform is used as solvent (e.g., in the case of
PHBHHx scaffold fabrication), a glass syringe should be used.
6. Be sure that no air bubbles are present in the syringe in order to
have a better control over polymeric solution flow rate during
scaffold fabrication. An effective way to place the solution
inside the syringe is removing the plunger and mounting a
Luer stop cap on the syringe in order to avoid the solution
flowing out. After the solution is poured into the syringe under
a fume hood, insert only partially the plunger, remove the Luer
stop cap, and eliminate the air inside the syringe by pushing
gently on the plunger. Finally mount the blunt tip needle on
the syringe.
7. Be sure that no solidified polymer is formed where the solution
can come in contact with air (e.g., at the tip of the syringe
before coupling it to the blunt tip needle or at the tip of the
needle while fixing the syringe to the pump due to an accidental
pressure on the plunger) in order to not compromise the feed
rate control. In case of polymer solution leaking during syringe
mounting on the pump, clean the needle tip accurately with
solvent-soaked paper.
8. You can use bi-adhesive tape to fix the beaker to the construction platform. The use of a Pyrex glass beaker is recommended
to avoid sample detachment during fabrication. In the case of
polymers showing high shrinkage degree during coagulation,
warming the coagulation bath of few degrees Celsius (e.g., up
to 25/26
C) can be an effective way to avoid sample
detachment.
9. It is advised to do the coordinates zeroing before filling the
beaker with the non-solvent in order to have a better visual
control of the actual needle tip position.
10. In all fabrication processes reported in Table 2, ethanol was
employed as a low toxic non-solvent suitable for polymer coagulation; when water was tested as a non-solvent, a homogeneous solution filament was not formed.
11. Although the volumes of solvent and non-solvent employed
and evaporated during the process are low, it is recommended
to perform the fabrication process under a fume hood.
12. Before starting the fabrication of the first layer, keep the needle
tip at a distance from the bottom of the beaker in order to ease
the observation of the extruded filament (see Note 13).
13. After the pump is started, small bubbles exiting from the
needle tip should be seen due to air inside the needle. Since
108
Dario Puppi and Federica Chiellini