Small Extracellular Vesicles for Severe and Profound Sudden Sensorineural Hearing Loss Treatment

This clinical trial aims to explore the effectiveness and safety of small extracellular vesicles, derived from mesenchymal stem cells, in treating severe and profound sudden sensorineural hearing loss. The study seeks to improve current treatments for sudden deafness by combining these vesicles with traditional drug therapy. Its primary goals are to determine if this combination enhances hearing recovery compared to traditional treatment alone, and to identify any potential medical issues associated with the intratympanic injection of these vesicles. During the Phase I trial, participants will undergo traditional drug treatment for sudden deafness, receive either small extracellular vesicles or a placebo injection, and visit the clinic every two weeks for checkups and tests. The injection dosage will range from low to high concentration, and any adverse reactions will be evaluated. In the Phase II trial, participants will be randomly assigned to either a control or an experimental group. The experimental group will receive intratympanic injections of small extracellular vesicles three times along with traditional treatment, while the control group will receive injections of dexamethasone. Both groups will have clinic visits 7 days, 1 month, and 3 months after treatment for hearing tests, speech audiometry, tinnitus disability scale, and visual analogue scale assessments.