1 Beijing Laboratory of Biomedical Materials, Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
2 Beijing Laboratory of Biomedical Materials, Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China. Electronic address: kqweiyan@bjmu.edu.cn.
3 Beijing Laboratory of Biomedical Materials, Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China. Electronic address: kqdengxuliang@bjmu.edu.cn.