Purpose

Lipid nanoparticles (SLN and NLC) were functionalized with the RVG29 peptide in order to target the brain and increase the neuronal uptake through the nicotinic acetylcholine receptors. These nanosystems were loaded with quercetin to take advantage of its neuroprotective properties mainly for Alzheimer’s disease.

Methods

The functionalization of nanoparticles with RVG29 peptide was confirmed by NMR and FTIR. Their morphology was assessed by transmission electron microscopy and nanoparticles size, polydispersity and zeta potential were determined by dynamic light scattering. The in vitro validation tests were conducted in hCMEC/D3 cells, a human blood-brain barrier model and thioflavin T binding assay was conducted to assess the process of amyloid-beta peptide fibrillation typical of Alzheimer’s disease.

Results

RVG29-nanoparticles displayed spherical morphology and size below 250 nm, which is compatible with brain applications. Zeta potential values were between −20 and −25 mV. Quercetin entrapment efficiency was generally higher than 80% and NLC nanoparticles were able to encapsulate up to 90%. The LDH assay showed that there is no cytotoxicity in hCMEC/D3 cell line and RVG29-nanoparticles clearly increased in 1.5-fold the permeability across the in vitro model of blood-brain barrier after 4 h of incubation compared with non-functionalized nanoparticles. Finally, this nanosystem was capable of inhibiting amyloid-beta aggregation in thioflavin T binding assay, suggesting its great potential for neuroprotection.

Conclusions

RVG29-nanoparticles that simultaneously target the blood-brain barrier and induce neurons protection against amyloid-beta fibrillation proved to be an efficient way of quercetin delivery and a promising strategy for future approaches in Alzheimer’s disease.

Graphical Abstract

中文翻译：

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用于槲皮素脑部递送和阿尔茨海默氏病的RVG29功能化脂质纳米颗粒。

目的

脂质纳米颗粒（SLN和NLC）被RVG29肽功能化，以靶向大脑并通过烟碱乙酰胆碱受体增加神经元摄取。这些纳米系统装有槲皮素，以利用其主要对阿尔茨海默氏病的神经保护特性。

方法

通过NMR和FTIR证实了具有RVG29肽的纳米颗粒的功能化。通过透射电子显微镜评估其形态，并通过动态光散射测定纳米粒子的大小，多分散性和ζ电势。在体外验证试验是在人心脏微血管内皮/ D3细胞，人血脑屏障模型和硫磺素T结合测定以评价淀粉样蛋白β肽颤动典型阿尔茨海默氏病的方法进行。

结果

RVG29纳米颗粒显示球形形态，尺寸小于250 nm，与大脑应用兼容。Zeta电位值在-20和-25 mV之间。槲皮素的包封率通常高于80％，而NLC纳米颗粒能够包封高达90％的包封率。LDH分析显示，在hCMEC / D3细胞系中没有细胞毒性，并且与未功能化的纳米颗粒相比，RVG29纳米颗粒在孵育4小时后跨血脑屏障体外模型的通透性明显提高了1.5倍。最后，该纳米系统能够在硫黄素T结合试验中抑制淀粉样蛋白β的聚集，表明其具有巨大的神经保护潜力。

结论

RVG29纳米粒子同时靶向血脑屏障并诱导神经元针对淀粉样β纤颤的保护被证明是槲皮素递送的有效方法，也是阿尔茨海默氏病未来治疗方法中的有希望的策略。

图形概要