Muscetti Ornella, Blal Naym, Mollo Valentina, Netti Paolo Antonio, Guarnieri Daniela
Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia (IIT@CRIB), Largo Barsanti e Matteucci 53, 80125 Naples, Italy.
Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II 132, 84084 Salerno, Italy.
Nanomaterials (Basel). 2023 Jul 3;13(13):1999. doi: 10.3390/nano13131999.
To improve the efficacy of nanoparticles (NPs) and boost their theragnostic potential for brain diseases, it is key to understand the mechanisms controlling blood-brain barrier (BBB) crossing. Here, the capability of 100 nm carboxylated polystyrene NPs, used as a nanoprobe model, to cross the human brain endothelial hCMEC/D3 cell layer, as well as to be consequently internalized by human brain tumor U87 cells, is investigated as a function of NPs' different intracellular localization. We compared NPs confined in the endo-lysosomal compartment, delivered to the cells through endocytosis, with free NPs in the cytoplasm, delivered by the gene gun method. The results indicate that the intracellular behavior of NPs changed as a function of their entrance mechanism. Moreover, by bypassing endo-lysosomal accumulation, free NPs were released from cells more efficiently than endocytosed NPs. Most importantly, once excreted by the endothelial cells, free NPs were released in the cell culture medium as aggregates smaller than endocytosed NPs and, consequently, they entered the human glioblastoma U87 cells more efficiently. These findings prove that intracellular localization influences NPs' long-term fate, improving their cellular release and consequent cellular uptake once in the brain parenchyma. This study represents a step forward in designing nanomaterials that are able to reach the brain effectively.
为提高纳米颗粒（NPs）的功效并增强其对脑部疾病的诊疗潜力，关键在于了解控制血脑屏障（BBB）穿越的机制。在此，以100 nm羧化聚苯乙烯纳米颗粒作为纳米探针模型，研究其穿越人脑内皮hCMEC/D3细胞层以及随后被人脑肿瘤U87细胞内化的能力，该能力是纳米颗粒不同细胞内定位的函数。我们将通过内吞作用递送至细胞内、局限于内溶酶体区室的纳米颗粒，与通过基因枪方法递送的、存在于细胞质中的游离纳米颗粒进行了比较。结果表明，纳米颗粒的细胞内行为因其进入机制而异。此外，通过绕过内溶酶体积累，游离纳米颗粒比内吞纳米颗粒更有效地从细胞中释放出来。最重要的是，一旦被内皮细胞排出，游离纳米颗粒会以比内吞纳米颗粒更小的聚集体形式释放到细胞培养基中，因此，它们能更有效地进入人胶质母细胞瘤U87细胞。这些发现证明，细胞内定位会影响纳米颗粒的长期命运，改善其在脑实质中的细胞释放及随后的细胞摄取。这项研究在设计能够有效抵达脑部的纳米材料方面向前迈进了一步。
