目的 探究巨噬细胞膜包被的黄芩苷脂质体（macrophage membrane-coated baicalin liposomes，MM-BA-LP）的血清稳定性、免疫逃逸及脑靶向性，以及其对小鼠脑全缺血再灌注损伤（global cerebral ischemia-reperfusion injury，GCIRI）的保护作用。方法 通过吸光度分析MM-BA-LP血清稳定性；利用荧光显微镜和流式细胞仪评估MM-BA-LP的免疫逃逸能力；使用活体成像系统研究MM-BA-LP在脑组织中的分布；通过CCK-8法确定安全给药范围；构建细胞氧糖剥夺/再灌注（oxygen glucose deprivation/reperfusion，OGD/R）模型和小鼠GCIRI模型，进行神经功能评分、旷场实验、苏木素-伊红（hematoxylin-eosin）染色以评价药效，并通过ELISA和Western blotting实验进行抗炎机制研究。结果 MM-BA-LP具有良好的血清稳定性；活体成像结果显示，MM-BA-LP组脑部荧光强度高于BA-LP组；CCK-8实验结果显示，MM-BA-LP对BV2细胞的毒性低于BA-LP；药效结果显示，MM-BA-LP显著改善GCIRI小鼠的运动和神经功能（P＜0.001），且能显著改善脑组织炎性病变；机制研究结果显示，MM-BA-LP能显著降低OGD/R细胞与GCIRI小鼠脑组织中高迁移率族蛋白B1（high mobility group box 1 protein，HMGB1）、Toll样受体4（Toll-like receptor 4，TLR4）和磷酸化核因子-κB（phosphorylated nuclear factor-κB，p-NF-κB）/NF-κB的表达（P＜0.05、0.01、0.001），且能显著下调炎症因子白细胞介素-6（interleukin-6，IL-6）、白细胞介素-1β、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）的水平（P＜0.05、0.01、0.001）；且HMGB1特异性抑制剂甘草酸与MM-BA-LP联用能显著改善GCIRI小鼠脑组织炎性病变。结论 MM-BA-LP具有良好的稳定性、免疫逃逸能力和脑靶向性，能显著抑制GCIRI后的炎症反应和神经功能损伤，其机制可能涉及HMGB1/TLR4/NF-κB通路。

Objective To investigate the serum stability, immune evasion and brain targeting of macrophage membrane-coated baicalin liposomes (MM-BA-LP), and study its protective effect on global cerebral ischemia-reperfusion injury (GCIRI) in mice. Methods The serum stability of MM-BA-LP was analyzed by absorbance; Fluorescence microscopy and flow cytometry were used to assess immune evasion of MM-BA-LP; The distribution of MM-BA-LP in brain tissue was studied using a in vivo bioluminescence imaging; The safe dosing range was determined by CCK-8 method; Oxygen glucose deprivation/reperfusion (OGD/R) model and mice GCIRI model were constructed, neurological severity score, open field experiments and hematoxylin-eosin (HE) staining were performed to evaluate drug efficacy, and the anti-inflammatory mechanism was studied by ELISA and Western blotting. Results MM-BA-LP had good serum stability. The results of in vivo imaging showed that the fluorescence intensity of MM-BA-LP group was higher than that of BA-LP group. The results of CCK-8 experiments showed that the toxicity of MM-BA-LP to BV2 cells was lower than that of BA-LP. The efficacy results showed that MM-BA-LP significantly improved the motor and nerve function of GCIRI mice (P < 0.001), and significantly improved the inflammatory lesions of brain tissue. Mechanistic studies showed that MM-BA-LP significantly reduced the expressions of high mobility group box 1 protein (HMGB1), Toll-like receptor 4 (TLR4) and phosphorylated nuclear factor-κB (p-NF-κB)/NF-κB in OGD/R cells and brain tissues of GCIRI mice (P < 0.05, 0.01, 0.001), and significantly down-regulated the levels of inflammatory cytokines such as interleukin-6 (IL-6), IL-1β and tumor necrosis factor-α (TNF-α) (P < 0.05, 0.01, 0.001). In addition, the combination of HMGB1 specifically inhibitor glycyrrhizic acid and MM-BA-LP significantly improved the inflammatory lesions of brain tissue in GCIRI mice. Conclusion MM-BA-LP has good serum stability, immune escape ability and brain targeting, and could significantly inhibit the inflammatory response and neurological impairment after GCIRI, and the mechanism may involve HMGB1/TLR4/NF-κB pathway.

R285.5

国家自然科学基金资助项目（82474220）