1. Eye Institute & Affiliated Xiamen Eye Center, School of Medicine, Xiamen University Xiamen, Fujian 361102, P. R. China
2. Fujian Provincial Key Laboratory of Ophthalmology and Visual Science & Ocular Surface and Corneal Diseases, Xiamen, Fujian 361102, P. R. China
3. Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
4. Institute of Sustainability for Chemicals, Energy and Environment (ISCE2) Agency for Science, Technology and Research (A*STAR) 2 Fusionopolis Way, Singapore 138634, Singapore
5. Department of Materials Science and Engineering, National University of Singapore 9 Engineering Drive 1, Singapore 117576, Singapore