Abstract

GelMa/ES-HA composite scaffold was sucessfully fabricated via freeze-drying process.
The cytotoxicity of composite scaffolds was low after 24 h incubations (The viability of
cells was above 85%). However, the cell viability decreased over time (71.9% after 48
h and 60.0% after 72 h). ALP activity of the cells grown on scaffold samples was
significantly higher than that of polystyrene plates under the same condition (p <0.05).
Also, ALP activity of scaffold samples increased over time. Osteocalcin synthesis for
the cells cultured on the GelMa/ES-HA scaffold was significantly higher than on the
polystyrene plate after 6 days of culture. The results of ALP activity and osteocalcin
synthesis suggest that the bioactive GelMa/ES-HA scaffold improved the development
of a mature osteoblast phenotype. SEM micrographs of the HOS cells grown on the
scaffold after culturing for 3 days confirmed the favorable cells growth of cells on the
surface of scaffold or between its pores and also formation of calcium deposits.
The histological examination of bone sections showed deposition of osteoid bone in all
studied groups after 1-week and immature bone spicules rimmed by osteoblasts were
observed more clearly in treatment groups. Significant osteoid matrix synthesis and
mineralization accelerated was by early cell differentiation. The number of osteocytes
and osteoblasts as mean values increased during the transition from the 1, 4 to 8 and
12-weeks of healing intervals among treatment groups. While, the Osteoclast
population in treatment groups decreased over time. The production of Osteocalsin,
Osteopointin and Osteronectin in treatment groups significantly increased over time
(p< 0.05). Furthermore, the difference between Osteocalsin, Osteopointin and
Osteonectin production in all treatment group and control groups was significant (p<
0.05) except for the 1 week groups. The maximum Osteocalsin, Osteopointin and
Osteronectin production belonged to 3 months treatment group which were 34.26,
42.43 and 34.26, respectively; which this values for 3 months control groups were
17.49, 14.73 and 14.50.
The results of this study showed that the novel GelMa/ES-HA composite scaffold is a
bioactive, biocompatible, biodegradable bone graft with desired mechanical and
swelling properties and excellent potential for enhancing bone regeneration process
which could serve as a promissing candidate for bone and dental tissue engineering
applications.