College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, 310014, China.
Department of Pharmacy, Jiangxi Medical College, Shangrao, 334000, China.
Eur J Med Chem. 2024 Oct 5;276:116674. doi: 10.1016/j.ejmech.2024.116674. Epub 2024 Jul 14.
Crocetin (CCT), a natural bioactive compound extracted and purified from the traditional Chinese medicinal herb saffron, has been shown to play a role in neurodegenerative diseases, particularly depression. However, due to challenges with solubility, targeting, and bioavailability, formulation development and clinical use of CCT are severely limited. In this study, we used the emulsification-reverse volatilization method to prepare CCT-loaded nanoliposomes (CN). We further developed a borneol (Bor) and lactoferrin (Lf) dual-modified CCT-loaded nanoliposome (BLCN) for brain-targeted delivery of CCT. The results of transmission electron microscope (TEM) and particle size analysis indicated that the size of BLCN (∼140 nm) was suitable for transcellular transport across olfactory axons (∼200 nm), potentially paving a direct path to the brain. Studies on lipid solubility, micropolarity, and hydrophobicity showed that BLCN had a relatively high Lf grafting rate (81.11 ± 1.33 %) and CCT entrapment efficiency (83.60 ± 1.04 %) compared to other liposomes, likely due to Bor improving the lipid solubility of Lf, and the combination promoting the orderly arrangement of liposome membrane molecules. Microplate reader and fluorescence microscopy analysis showed that BLCN efficiently promoted the endocytosis of fluorescent coumarin 6 into HT22 cells with a maximal fluorescence intensity of (13.48 ± 0.80 %), which was significantly higher than that of CCT (5.73 ± 1.17 %) and CN (12.13 ± 1.01 %). BLCN also exhibited sustained function, remaining effective for more than 12 h after reaching a peak at 1 h in cells, while CN showed a significant decrease after 4 h. The uptake mechanisms of BLCN in HT22 cells mainly involve energy-dependent, caveolae-mediated, and microtubule-mediated endocytosis, as well as micropinocytosis. Furthermore, BLCN displayed a significant neuroprotective effect on HT22 cells in glutamate-, corticosterone-, and HO-induced models. Tissue fluorescence image analysis of mice showed that BLCN exhibited substantial retention of fluorescent DiR in the brain after nasal administration for 12 h. These findings suggest that CCT has the potential for cellular uptake, neuroprotection, and targeted delivery to the brain following intranasal administration when encapsulated in Bor and Lf dual-modified nanoliposomes.
西红花酸（CCT）是从传统中药藏红花中提取和纯化的天然生物活性化合物，已被证明在神经退行性疾病中发挥作用，特别是在抑郁症中。然而，由于溶解度、靶向性和生物利用度方面的挑战，西红花酸的制剂开发和临床应用受到严重限制。在本研究中，我们使用乳化-反挥发法制备了西红花酸负载纳米脂质体（CN）。我们进一步开发了一种冰片（Bor）和乳铁蛋白（Lf）双重修饰的西红花酸负载纳米脂质体（BLCN），用于西红花酸的脑靶向递药。透射电子显微镜（TEM）和粒径分析的结果表明，BLCN 的大小（约 140nm）适合穿过嗅轴的细胞内转运（约 200nm），可能为大脑开辟了直接途径。脂质溶解度、微极性和疏水性研究表明，与其他脂质体相比，BLCN 具有相对较高的 Lf 接枝率（81.11±1.33%）和西红花酸包封率（83.60±1.04%），这可能是由于 Bor 提高了 Lf 的脂溶性，并且这种结合促进了脂质体膜分子的有序排列。微孔板阅读器和荧光显微镜分析表明，BLCN 能够有效促进荧光香豆素 6 被 HT22 细胞内吞，最大荧光强度为（13.48±0.80%），明显高于西红花酸（5.73±1.17%）和 CN（12.13±1.01%）。BLCN 还表现出持续的功能，在细胞中达到 1 小时的峰值后，12 小时内仍然有效，而 CN 在 4 小时后显著下降。BLCN 在 HT22 细胞中的摄取机制主要涉及能量依赖、网格蛋白介导和微管介导的内吞作用以及微胞饮作用。此外，BLCN 对谷氨酸、皮质酮和 HO 诱导的 HT22 细胞模型具有显著的神经保护作用。小鼠组织荧光图像分析表明，BLCN 经鼻腔给药 12 小时后，大脑中保留了大量荧光 DiR。这些发现表明，西红花酸在包封于 Bor 和 Lf 双重修饰的纳米脂质体后，通过鼻腔给药具有细胞摄取、神经保护和靶向递药到大脑的潜力。
