超顺磁性氧化铁纳米粒（SPIONs）是一种新型靶向递药系统，因其具有反应性高、载药量大、生物毒性低、磁学性能特殊等特点，近年迅速成为医学研究热点。缺血性脑卒中是脑卒中主要类型，其病理生理机制复杂，目前除缺血后短时间内进行溶栓外，尚无较好治疗手段。肌肽是一种天然二肽化合物，具有较强抗氧化、抗自由基作用，课题组前期研究发现肌肽具有抗缺血性脑损伤作用，但有效剂量大，难以应用。本项目采用SPIONs靶向递送肌肽进入脑缺血半暗带，并利用SPIONs增强磁共振弛豫信号强度的特点，实现脑缺血的高效诊疗。前期相关研究已表明载药SPIONs具有良好磁响应性、中枢靶向及在缺血灶区释药的性能，本项目进一步评价SPIONs靶向调控机制及其递送肌肽对抗脑缺血的作用，通过磁调控、生物相容性、体内外靶向性及模型大鼠药动-药效研究，探讨脑缺血诊疗新策略，同时为丰富SPIONs靶向递药治疗中枢疾病方面做出有益尝试。

Superparamagnetic iron oxide nanoparticles （SPIONs）, possessing property of high reactivity, electromagnetic specialty and good biological safety, are novel promising targeting drug delivery system and can be used in several biomedical applications. Cerebral ischemic stroke（CIS）, one of the most prevalent central neurological disorders is now facing limited effective treatment approaches, due to lack of targeting ability and severe adverse drug reaction. As most CIS has a characteristic of partial attack, we plan to use SPIONs to deliver carnosine, a kind of dipeptide neuroprotective agents into the ischemia penumbra and to realize the high efficient diagnosis and treatment for CIS. Our preliminary experiments demonstrated that the delivery of SPIONs can manipulated via external magnetic field in vitro and target to brain in vivo. Further study will be performed to investigate the targeted control mechanism and relationship between anti-CIS efficacy and drug delivery. And the magnetic responsiveness, nervous system biocompatibility, targeting properties and PK-PD study in animals will also be performed. With this project, we’re going to put forward a feasible brain-targeting pharmacotherapeutic approach combating CIS.