Cryopreservation of Human Nasal Ciliated Epithelium

Abstract

The purpose of this study was to compare the effects on human nasal cilia of various freezing and thawing methods in order to determine a reliable method of cryopreservation. Ten samples each were preserved by a slow freezing and a fast freezing method. All samples were stored in liquid nitrogen (–196°C) for 1 week. The frozen samples were thawed by one of two methods: 1) rapid thawing—37°C water bath for 3–4 minutes; and 2) slow thawing—room temperature for 15 minutes. Prefreeze and postthaw ciliary beat frequency (CBF) was measured. The slow freezing and fast thawing method (SFFT) resulted in the best viability. An additional 10 samples preserved using the SFFT method stored at –70°C to –90°C did not retain ciliary function. Thirty ciliated samples preserved by the SFFT method were examined after freezing in liquid nitrogen (–196°C) for 1 week, 2 weeks, and 1 month. There was no significant decrease in CBF after cryopreservation at –196°C for 1 week or 2 weeks (P> 0.05). As the storage time increased to 1 month, postthaw CBF decreased 7.25 ± 0.87% when compared to the prefreeze CBF (P < 0.05). We conclude that human nasal cilia preserved by SFFT at –196°C retain activity for up to 1 month.