Macroporous hydrogels have great potential for biomedical
applications.
Liquid or gel-like pores were created in a photopolymerizable hydrogel
by forming water-in-water emulsions upon mixing aqueous solutions of gelatin and a poly(ethylene oxide)
(PEO)-based triblock copolymer. The copolymer constituted the continuous
matrix, which dominated the mechanical properties of the hydrogel
once photopolymerized. The gelatin constituted the dispersed phase,
which created macropores in the hydrogel. The microstructures of the
porous hydrogel were determined by the volume fraction of the gelatin
phase. When volume fractions were close to 50 v%, free-standing hydrogels
with interpenetrated morphology can be obtained thanks to the addition
of a small amount of xanthan. The hydrogels displayed Young’s
moduli ranging from 5 to 30 kPa. They have been found to be non-swellable
and non-degradable in physiological conditions. Preliminary viability
tests with hepatic progenitor cells embedded in monophasic PEO-based
hydrogels showed rapid mortality of the cells, whereas encouraging
viability was observed in PEO-based triblock copolymer/gelatin macroporous
hydrogels. The latter has the potential to be used in cell therapy.