School of Life Sciences, Jilin University, Changchun 130012, China.
Engineering Laboratory for AIDS Vaccine, Jilin University, Changchun 130012, China.
Int J Mol Sci. 2022 Oct 11;23(20):12071. doi: 10.3390/ijms232012071.
In recent years, cyclic peptides have attracted much attention due to their chemical and enzymatic stability, low toxicity, and easy modification. In general, the self-assembled nanostructures of cyclic peptides tend to form nanotubes in a cyclic stacking manner through hydrogen bonding. However, studies exploring other assembly strategies are scarce. In this context, we proposed a new assembly strategy based on cyclic peptides with covalent self-assembly. Here, cyclic peptide-(DPDPDP) was rationally designed and used as a building block to construct new assemblies. With cyclo-(DP) as the structural unit and 2,2'-diamino-N-methyldiethylamine as the linker, positively charged nanospheres ((CP)NS) based on cyclo-(DP) were successfully constructed by covalent self-assembly. We assessed their size and morphology by scanning electron microscopy (SEM), TEM, and DLS. (CP)NS were found to have a strong positive charge, so they could bind to siRNA through electrostatic interactions. Confocal microscopy analysis and cell viability assays showed that (CP)NS had high cellular internalization efficiency and low cytotoxicity. More importantly, real-time polymerase chain reaction (PCR) and flow cytometry analyses indicated that (CP)NS-siRNA complexes potently inhibited gene expression and promoted tumor cell apoptosis. These results suggest that (CP)NS may be a potential siRNA carrier for gene therapy.
近年来，由于环肽具有化学和酶学稳定性、低毒性和易于修饰等特点，引起了人们的广泛关注。通常，环肽的自组装纳米结构倾向于通过氢键以环状堆叠的方式形成纳米管。然而，探索其他组装策略的研究却很少。在这种情况下，我们提出了一种基于共价自组装的环肽新组装策略。在这里，我们合理设计了环肽-(DPDPDP)并将其用作构建新组装体的构建块。以环-(DP)为结构单元，以 2,2'-二氨基-N-甲基二乙胺为连接体，通过共价自组装成功构建了基于环-(DP)的带正电荷的纳米球((CP)NS)。我们通过扫描电子显微镜(SEM)、TEM 和 DLS 评估了它们的尺寸和形态。(CP)NS 具有很强的正电荷，因此可以通过静电相互作用与 siRNA 结合。共聚焦显微镜分析和细胞活力测定表明，(CP)NS 具有很高的细胞内化效率和低细胞毒性。更重要的是，实时聚合酶链反应(PCR)和流式细胞术分析表明，(CP)NS-siRNA 复合物能够有效抑制基因表达并促进肿瘤细胞凋亡。这些结果表明，(CP)NS 可能是一种用于基因治疗的潜在 siRNA 载体。
