1. Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Xueyuan Road 38, Beijing 100191, China
2. Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Xueyuan Road 38, Beijing 100191, China
3. Department of Ultrasound, Peking University Third Hospital, Peking University, Xueyuan Road 38, Beijing 100191, China