School of Chemistry and Chemical Engineering Harbin Institute of Technology Harbin 150090 China;
Department of Neurosurgery Yale University New Haven CT 06510 USA;
College of Biological Sciences and Biotechnology Beijing Forestry University Beijing 100083 China;
Department of Chemistry Beijing Normal University Beijing 100875 China;
Department of Biomedical Engineering Yale University New Haven CT 06510 USA;
Beijing Key Laboratory of Polymorphic Drugs Institute of Materia Medico Chinese Academy cf Medical Sciences and Peking Union Medical College Beijing 100050 China;
Department of Pathology Yale University New Haven CT 06510 USA;
natural material; oral drug delivery; nano particle; dehydrotrametenolic acid(DTA);