Globally, one of the most common tissue transplantation
procedures
is bone grafting. Lately, we have reported the development of polymerized
high internal phase emulsions (PolyHIPEs) made of photocurable polycaprolactone
(4PCLMA) and shown their potential to be used as bone tissue engineering
scaffoldsin vitro. However, it is essential to evaluate
thein vivoperformance of these scaffolds to investigate
their potential in a clinically more relevant manner. Therefore, in
this study, we aimed to comparein vivoperformances
of macroporous (fabricated using stereolithography), microporous (fabricated
using emulsion templating), and multiscale porous (fabricated using
emulsion templating and perforation) scaffolds made of 4PCLMA. Also,
3D-printed macroporous scaffolds (fabricated using fused deposition
modeling) made of thermoplastic polycaprolactone were used as a control.
Scaffolds were implanted into a critical-sized calvarial defect, animals
were sacrificed 4 or 8 weeks after implantation, and the new bone
formation was assessed by micro-computed tomography, dental radiography,
and histology. Multiscale porous scaffolds that include both micro-
and macropores resulted in higher bone regeneration in the defect
area compared to only macroporous or only microporous scaffolds. When
one-grade porous scaffolds were compared, microporous scaffolds showed
better performance than macroporous scaffolds in terms of mineralized
bone volume and tissue regeneration. Micro-CT results revealed that
while bone volume/tissue volume (Bv/Tv) values were 8 and 17% at weeks
4 and 8 for macroporous scaffolds, they were significantly higher
for microporous scaffolds, with values of 26 and 33%, respectively.
Taken together, the results reported in this study showed the potential
application of multiscale PolyHIPE scaffolds, in particular, as a
promising material for bone regeneration.