1. Department of Polymer Science and Engineering, Chungnam National University, Daejeon, Korea.
2. Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon, Korea.
3. Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, Korea.
4. Brain Research Institute, College of Medicine, Chungnam National University, Daejeon, Korea.