posted on 2015-11-09, 00:00authored byEce Alpaslan, Hilal Yazici, Negar H. Golshan, Katherine
S. Ziemer, Thomas J. Webster
Cerium
oxide nanoparticles (or nanoceria) have demonstrated great
potential as antioxidants in various cell culture models. Despite
such promise for reducing reactive oxygen species and an ability for
surface functionalization, nanoceria has not been extensively studied
for cancer applications to date. Herein, we engineered the surface
of nanoceria with dextran and observed its activity in the presence
bone cancer cells (osteosarcoma cells) at different pH values resembling
the cancerous and noncancerous environment. We found that dextran
coated nanoceria was much more effective at killing bone cancer cells
at slightly acidic (pH 6) compared to physiological and basic pH values
(pH 7 and pH 9). In contrast, minimal toxicity was observed for healthy
(noncancerous) bone cells when cultured with nanoceria at pH = 6 after
1 day of treatment in the concentration range of 10–1000 μg/mL.
Although healthy bone cancer cell viability decreased after treatment
with high ceria nanoparticle concentrations (250–1000 μg/mL)
for longer time periods at pH 6 (3 days and 5 days), approximately
2–3 fold higher healthy bone cell viabilities were observed
compared to osteosarcoma cell viability at similar conditions. Very
low toxicity was observed for healthy osteoblasts cultured with nanoceria
for any concentration at any time period at pH 7. In this manner,
this study provides the first evidence that nanoceria can be a promising
nanoparticle for treating bone cancer without adversely affecting
healthy bone cells and thus deserves further investigation.