Preliminary Characterization of Extracellular Vesicles From Auditory HEI-OC1 Cells. (June 2019)

• Record Type: Journal Article
• Authors: Kalinec, Gilda M.; Cohn, Whitaker; Whitelegge, Julian P.; Faull, Kym F.; Kalinec, Federico
• Other Names: Moon Sung K. guest-editor.; Kawauchi Hideyuki guest-editor.; Oh Seung-Ha guest-editor.
• Is Part Of: Annals of otology, rhinology & laryngology. Volume 128(2019)Supplement 6
• Page Start: 52S
• Page End: 60S
• Publication Date: 2019-06
• Subjects: extracellular vesicles -- HEI-OC1 cells -- proteomics -- drug nanocarriers -- intracochlear drug delivery; Otolaryngology -- Periodicals; 617.51
• DOI: 10.1177/0003489419836226
• Languages: English
• ISSNs: 0003-4894

Abstract

Objectives: Isolate, purify, and characterize extracellular vesicles (EVs) obtained from auditory HEI-OC1 cells, and evaluate their suitability for intracochlear transport and delivery of pharmacological drugs and/or pro-resolution mediators of acute inflammatory processes. Methods: HEI-OC1 EVs were isolated and purified using the exoEasy Maxi Kit, and their size was evaluated by nanoparticle tracking techniques. Bottom-up proteomics of the EVs, either freshly obtained or stored for up to 4 months at −20°C, was performed by LC-ESI-MS/MS. LC-ESI-MS/MS-MRM was used to measure the loading of dexamethasone inside EVs following co-incubation at room temperature for 1 hour with and without 5 minutes sonication. Results: Routinely, we were able to obtain purified fractions of >2 × 10 9 EVs/mL, with diameters varying between 50 and 800 nm. Bottom-up proteomics showed that among the most abundant EVs proteins, 19.2% were cytoplasmic, 17.2% were membrane localized, 12.3% were cytosolic, and 14.6% were nucleolar. No significant differences between fresh and stored EVs were detected. Importantly, co-incubation of HEI-OC1 EVs (1 × 10 8 EVs/mL) with dexamethasone (10 mM) resulted in the incorporation of 10.1 ± 1.9 nM dexamethasone per milliliter of EVs suspension. Conclusions: Altogether, the results suggest that EVs from HEI-OC1 cells could be advantageously used as biological nanocarriers for the delivery of specific molecules and pharmacological drugs into the inner ear.