Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
Curr Drug Deliv. 2021;18(1):31-43. doi: 10.2174/1567201817666200804105017.
Polyamidoamine (PAMAM) dendrimers are attracting interest of the scientists as vehicles for nucleic acid delivery due to their suitable properties. The highly positive surface charged of PAMAM enables an adequate interaction with negatively charged microRNAs.
The purpose of this study is to investigate the anti-tumor effect of microRNA Mimic let-7b loaded in PAMAM dendrimers (G5) on Non-Small Cell Lung Cancer (NSCLC) cells.
In order to increase the anti-tumor effect, chloroquine is employed to enhance the endosomal escape which is counted as a limitation in the advancement of gene delivery. Nanoparticles (NPs) were coated with natural polysaccharide "Hyaluronic Acid (HA)" to develop biodegradable carriers with targeting moiety for over-expressed CD44 receptors on NSCLC cells. The size and zeta potential measurements, gel retardation, cellular uptake, cell viability and gene expression studies were investigated for the designed delivery system.
DLS analysis showed monodispersed small nanoparticles, which was in agreement with TEM results. Remarkably, NPs in the cells pretreated with chloroquine exhibited the highest cytotoxicity and were capable of inducing apoptosis. In cellular uptake study, NPs labeled with Fluorescein Isothiocyanate (FITC), were successfully taken up in cancer cells. Moreover, the expression study of three genes linked with cancer initiation and development in NSCLC, including KRAS, p-21, and BCL-2 indicated a decrease in KRAS and BCL-2 (oncogenic and anti-apoptotic genes) and increase in p-21 (apoptotic gene).
All factors considered, the results declare that application of let-7b-loaded PAMAM-HA NPs in combination with chloroquine can be a promising therapeutic option in cancer cells inhibition. This fact has frequently been highlighted by many researchers upon the potentials of micro RNA delivery in cancer cells.
聚酰胺-胺（PAMAM）树枝状聚合物由于其合适的性质，作为核酸传递载体引起了科学家的兴趣。PAMAM 的高度正表面电荷使它能够与带负电荷的 microRNA 充分相互作用。
本研究旨在探讨负载 microRNA 模拟物 let-7b 的 PAMAM 树枝状聚合物（G5）对非小细胞肺癌（NSCLC）细胞的抗肿瘤作用。
为了提高抗肿瘤效果，采用氯喹增强内涵体逃逸，这被认为是基因传递进展的一个限制。纳米颗粒（NPs）用天然多糖“透明质酸（HA）”包被，以开发具有针对 NSCLC 细胞过度表达的 CD44 受体的靶向部分的可生物降解载体。对设计的递药系统进行了粒径和 zeta 电位测量、凝胶阻滞、细胞摄取、细胞活力和基因表达研究。
DLS 分析显示单分散的小纳米颗粒，这与 TEM 结果一致。值得注意的是，在用氯喹预处理的细胞中，NP 表现出最高的细胞毒性，并能够诱导细胞凋亡。在细胞摄取研究中，用荧光素异硫氰酸酯（FITC）标记的 NPs 成功地被癌细胞摄取。此外，对与 NSCLC 中癌症起始和发展相关的三个基因（KRAS、p-21 和 BCL-2）的表达研究表明，KRAS 和 BCL-2（致癌和抗凋亡基因）减少，p-21（凋亡基因）增加。
综上所述，结果表明，负载 let-7b 的 PAMAM-HA NPs 与氯喹联合应用可能是抑制癌细胞的一种有前途的治疗选择。这一事实经常被许多研究人员强调，认为 microRNA 传递在癌细胞中的潜力。
