**Acknowledgements**

The authors would like to thank (a) the Chuan Ratanarak Foundation; (b) the Neurosurgery Unit, Surgery Department, Faculty of Medicine Ramathibodi Hospital Mahidol University, Thailand; and (c) the Industrial Chemistry Department, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Thailand for financial support (in-house grant no. 5841103 and KMUTNB-62-DRIVE-036).
