  A very small number of biomaterials investigated for bone regeneration was
reported as able to prevent the oxidative stress. In this study beads based on
alginate hydrogel and mesoporous glasses (MG) containing different amounts of
cerium oxides (Ce3+/Ce4+) exhibiting antioxidant properties were investigated
as a good approach to mimic the action of antioxidant enzymes in our organism.
The effect of cerium contents on the bioactivity and biocompatibility of beads
were investigated. Moreover, the potential capability of Ce-containing MG to
prevent the oxidative stress caused by the activity of reactive oxygen species
(ROS) was here investigated for the first time. The increment of cerium oxide
from 1.2, to 3.6 and 5.3 mol-% decreases the surface area and porosity of MG
and increases the catalase mimetic activity after 168 h. Swelling tests in
different cell culture media (D- and {\alpha}-MEM) demonstrated the rehydration
capability of beads. The presence of beads with the highest Ce-contents (3.6
and 5.3 %) improved the proliferation of pre-osteoblastic cells MC3T3-C1 cells.
However, the cell differentiation decreased when increased the cerium content.
Lactate dehydrogenase assays showed beads are cytocompatible materials.
Moreover, oxidative stress tests with H2O2 showed a better response related to
cell viability and the elimination of oxidant species when increased cerium
content. Beads of glasses with 1.2 and 3.6 % of CeO2 are excellent candidates
as bioactive scaffolds for bone regeneration capable of counteract the
oxidative stress.
