乏氧响应型磷光探针的制备及对脑中风损伤区的识别成像研究

Ischemic stroke is a kind of acute disease may cause permanent damages, so rapid identification of damage areas and real-time observation of pathological changes are needed. But now, there is a lack of effective means in the detection of stroke so as to block early diagnosis and targeted therapy. The stroke damage areas have the characteristics of lack of oxygen, so can be detected by hypoxia-sensitive luminescence probes. But now most of the hypoxia-sensitive probes reported rarely could be used in the detection of brain blood vessels, especially in vivo imaging. In this project, a series of hypoxia phosphorescence probes with two-photon excitation will be prepared. As phosphorescence probes loaded in the polymer microspheres are sensitivity to oxygen, the damage areas of stroke with low oxygen levels will enhance the phosphorescence intensity of the probes and could be identified. Through modification of the structure with suitable groups will improve the two-photon absorption of probes, surface modification of the load materials will improve the biocompatibility effectively, so this kind of probes will meet the requirements of imaging in vivo. Using Two-photon imaging technology can realize high signal-to-noise ratio imaging of brain blood vessels in living mice, especially the recognition imaging and evaluation in stroke damage areas. The results from the present project will favor the development of timely diagnosis and real-time detection of stroke, and provide idea for the targeted therapy and repair in damage areas.

脑中风具有突发性和永久损伤性的特点，迫切需要发展一些有效的有段，能对发病后中风损伤区进行快速识别和实时观测。利用脑中风损伤区的乏氧特性可对其进行特异性识别成像，但目前报道的大部分乏氧探针并不适用于脑血管环境中的检测，且极少能运用于活体成像。本研究拟制备一系列具有双光子吸收的乏氧响应型磷光探针，通过溶胀分散法负载于高分子微球内，利用小鼠脑中风损伤区的缺氧环境可点亮磷光探针，从而实现识别成像的目的。通过对探针分子的结构优化提高其双光子吸收性能，对负载载体的形貌调控和表面修饰改善其生物相容性，从而满足活体成像的要求。利用双光子成像技术实现对活体小鼠脑部血管高信噪比的成像，特别是对缺血性脑中风损伤区的特异性识别和损伤评估。此研究为脑中风的病理研究和诊断检测提供新的手段，也为中风损伤区的靶向治疗和修复提供新的思路。

脑中风具有突发性和永久损伤性的特点，迫切需要发展一些有效的有段，能对发病后中风损伤区进行快速识别和实时观测。本研究项目以获得适用于脑部血管精细结构稳定标记的新型血管造影剂为目标，从而用于脑中风损伤区的精准定位和血管损伤过程的实时监测。我们设计制备了一系列具有高荧光量子产率、高稳定性、生物相容性好的探针分子和聚合物纳米颗粒，结合组织透明技术，发展了一种兼容其他标记技术，并能够对透明化的大组织中血管网络精细结构进行深层成像和三维重建的新技术。利用近红外和双光子成像技术，实现了活体小鼠脑部血管损伤及血流恢复过程中血流速度和血管结构变化过程的实时监测。利用缺血性脑中风模型，实现了缺血性脑中风/血流重灌注全过程的实时成像、脑中风半影区的准确定位以及中风后血管损伤程度的定性评估。本研究的研究成果，为脑血管相关疾病的研究和诊断以及血管损伤后的修复和治疗提供了一种新的观测和评估手段。发表标注本基金项目资助的论文5篇，申请中国发明专利2项。同时，本项目取得的成果还包括待发表的论文2篇。