1. a Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea
2. b Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea; R & D Center, I-cure Pharmaceutical Corporation, 190-1 Sandaewon Dong, Jungwon Gu, Seongnam 462-807, South Korea
3. c Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea
4. d Rigen Biotech, 66-2 Sandaewon Dong, Jungwon Gu, Seongnam 462-120, South Korea
5. e Rigen Biotech, 66-2 Sandaewon Dong, Jungwon Gu, Seongnam 462-120, South Korea
6. f Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea