神经干细胞膜修饰的多功能免疫-纳米复合物用于胶质瘤靶向诊断与融合治疗

Cerebral glioma has a high mortality and recurrence rate. The residual glioma cells in the peripheral area of tumors and glioma stem cells in the subependymal region result in tumor recurrence. Owing to convenient surface modification and being easily loaded with imaging contrast, drug and physiotherapy nano materials, polymeric nanomaterials have attracted increasing attention in targeted diagnosis and therapy of glioma in recent years. However, the high reticuloendothelial system clearance rate of polymeric nanomaterials and the blocking-up of blood-brain barrier have strongly hindered their further clinical application. According to our previous study, cell membrane engineering, due to the extended blood retension time and immune-evading capabilities, has been proposed as a promising strategy to overcome these technique obstacles. In this study, neuro stem cell membrane should be used in the surface modification of multifunctional nano material, which has several intrinsic capabilities as upconversional luminescence imaging(UCL)/MRI contrast agents and photodynamic therapy drugs. Furthermore, a lipid-insertion method is employed to functionize this nanoparticles by a 131I labeled mice derived antiglioma B7-H3 monoclonal antibody(mAb) 18F9. In vivo and ex vivo macrophage uptake and cell binding assay with mice glioma cells, photodynamic therapy(PDT) combined internal radiation therapy(IRT), as well as UCL/MRI/SPECT multimodal imaging should be carried out to verify whether the NSC membrane coated nanoparticles have simultaneously integrated the multiple capabilities of immune-evading and auto-tracking of glioma cells and glioma stem cells, as well as multimodal imaging and combined therapy mediated by the stem cell and mAb. Here, we illustrate a rational design to achieve new breakthroughs in targeted diagnosis and therapy of gliomas.

脑胶质瘤术后易复发，死亡率高，肿瘤周边残存的胶质瘤细胞及室管膜下区残存胶质瘤干细胞是肿瘤复发的根源。高分子纳米材料易于表面修饰，可负载成像、药物及物理治疗材料，成为近年来胶质瘤靶向诊断与治疗的热点，但高网状内皮系统清除率及血脑屏障阻断等因素限制了其进一步应用。本项目组前期研究表明，细胞膜工程技术修饰的纳米材料具有长循环及免疫逃逸等特点，有望克服上述技术障碍。本研究拟采用神经干细胞膜修饰具有上转换光学/MRI及光动力治疗特性的多功能纳米材料，采用脂质插入技术连接131I标记的胶质瘤鼠源性B7-H3抗体18F9，通过体内、外巨噬细胞与小鼠胶质瘤细胞结合实验，以及光动力治疗联合内照射治疗与光学/MRI/SPECT多模态成像，验证神经干细胞膜修饰的纳米材料免疫逃逸及体内自动追踪胶质瘤细胞与胶质瘤干细胞的能力、抗体与干细胞双重靶向介导的多模态成像与联合治疗的可行性，实现胶质瘤靶向诊断与治疗的新突破。

脑胶质瘤是颅内最常见的原发肿瘤。外科手术是治疗胶质瘤最有效的手段。但是考虑到脑功能的保留，术区不宜过大；加之胶质瘤细胞在脑组织内易全脑转移，胶质瘤术后复发率非常高。神经干细胞对胶质瘤细胞有定向迁移的作用。经过绿色荧光蛋白标记的神经干细胞能够清晰指示胶质瘤的转移“路径”。大粒径的超顺磁性氧化铁在具有作为磁共振造影剂，可以实现体外成像的同时，也具有非常好的光热效应，可以定向杀伤胶质瘤细胞。但是由于血脑屏障的存在，超顺磁性氧化铁纳米颗粒较难进入颅内。因此，本研究采用经过绿色荧光蛋白标记的神经干细胞负载超顺磁性氧化铁颗粒，双标记的神经干细胞进入颅内后，通过其定向迁移能力，将具有光热效应的超顺磁性氧化铁运载到胶质瘤细胞附近。研究已经表明，通过荧光显微镜对标记了绿色荧光蛋白的神经干细胞可以在胶质瘤内部及附近得到显示。同时，通过体外磁共振扫描，也能观测到胶质瘤内部以及附近的超顺磁性氧化铁。之后通过体外的光热治疗，对胶质瘤以及胶质瘤细胞进行杀伤，可以观察到肿瘤体积相对于对照组的明显减小。从而实现胶质瘤的靶向诊断与治疗。