Chitosan films promote formation of olfactory neurospheres and differentiation of olfactory receptor neurons

Abstract

Background: Olfactory dysfunction significantly impairs the life quality of patients. Therefore, a model needs to be developed for anosmia. Chitosan is a biodegradable natural polysaccharide that has been widely studied for regenerative purposes in the nervous system. However, whether chitosan promotes differentiation of olfactory receptor neurons or regulates formation of neurospheres in the olfactory system remains unexplored. Methodology: Olfactory neuroepithelial cells were isolated from embryonic wistar rats on day 17, and cultured on controls and chitosan films for 12 days. The effects of treatment were assessed using immunocytochemistry, quantitative polymerase chain reaction and western blots following culturing. The substrate of poly-L-lysine-co-laminin was adopted as a control. Results: In contrast to the flat layer on controls, olfactory neuroepithelial cells form olfactory neurospheres on chitosan films with steadily increasing diameter. The olfactory neurospheres contain basal cells, as well as immature and mature olfactory receptor neurons. The expression level of olfactory marker protein is higher on chitosan films than those on controls in gene and protein levels, and the olfactory transduction elements also express a similar trend. Mature olfactory receptor neurons are found predominantly at the periphery of the olfactory neurospheres. Conclusions: Chitosan films not only facilitate formation of olfactory neurospheres, but also promote differentiation of olfactory receptor neurons. Chitosan is a potential biomaterial to establish an in vitro culture model to treat olfactory dysfunction in future.

From prevention to optimal treatment in chronic rhinosinusitis

“…In patients with post-traumatic or post-infectious olfactory loss, olfactory training represents an effective treatment, with Hummel et al (9) reporting for the first time the associated increase in electroolfactogram responses to pleasant and unpleasant odors. In an attempt to further explore novel therapeutic pathways for anosmia, Li et al (10) utilized olfactory neuroepithelial cells from embryonic rats to assess the effects of chitosan on neurosphere formation and differentiation of olfactory receptor neurons, with promising findings. Smell disorders in relation to drug intake in the elderly, has been studied by Ottaviano et al (11) , confirming the clinical observation of correlation between the number of drugs taken for non-rhinologic conditions and smell impairment.…”