Abstract：
Nucleic Acid Nanocapsules (NANs) are nucleic acid nanostructures that radially display oligonucleotides on the surface of cross-linked surfactant micelles. Their chemical makeup affords the stimuli-responsive release of therapeutically active DNA-surfactant conjugates into the cells. While NANs have so far demonstrated the effective cytosolic delivery of their nucleic acid cargo, as seen indirectly by their gene regulation capabilities, there remain gaps in the molecular understanding of how this process happens. Herein, we examine the enzymatic degradation of NANs and confirm the identity of the DNA-surfactant conjugates formed by using mass spectrometry (MS). With surface enhanced (resonance) Raman spectroscopy (SE(R)RS), we also provide evidence that the energy-independent translocation of such DNA-surfactant conjugates is contingent upon their release from the NAN structure, which, when intact, otherwise buries the hydrophobic surfactant tail in its interior. Such information suggests a critical role of the surfactant in the lipid disruption capability of the DNA surfactant conjugates generated from degradation of the NANs. Using NANs made with different tail lengths (C12 and C10), we show that this mechanism likely holds true despite significant differences in the physical properties (i.e., critical micelle concentration (CMC), surfactants per micelle, Nagg) of the resultant particles (C12 and C10 NANs). While the total cellular uptake efficiencies of C12 and C10 NANs are similar, there were differences observed in their cellular distribution and localized trafficking, even after ensuring that the total concentration of DNA was the same for both particles. Ultimately, C10 NANs appeared less diffuse within cells and colocalized less with lysosomes over time, achieving more significant knockdown of the target gene investigated, suggesting more effective endosomal escape. These differences indicate that the surfactant assembly and disassembly properties, including the number of surfactants per particle and the CMC can have important implications for the cellular delivery efficacy of DNA micelles and surfactant conjugates.
摘要：
核酸纳米胶囊(NAN)是在交联的表面活性剂胶束的表面上径向展示寡核苷酸的核酸纳米结构。它们的化学组成使治疗活性DNA-表面活性剂缀合物的刺激响应性释放进入细胞。虽然到目前为止，NAN已经证明了其核酸货物的有效胞质递送，从它们的基因调控能力间接看出，在分子对这个过程是如何发生的理解方面仍然存在差距。在这里，我们检查了NAN的酶促降解，并确认了通过使用质谱（MS）形成的DNA-表面活性剂缀合物的身份。用表面增强（共振）拉曼光谱（SE（R）RS），我们还提供证据表明，这种DNA-表面活性剂缀合物的能量非依赖性易位取决于它们从NAN结构中的释放，which,完好无损时，否则将疏水性表面活性剂尾部埋在其内部。这些信息表明表面活性剂在由NAN降解产生的DNA表面活性剂缀合物的脂质破坏能力中的关键作用。使用具有不同尾部长度（C12和C10）的NAN，我们表明，尽管物理性质存在显着差异，但这种机制可能是正确的(即，临界胶束浓度(CMC)，每个胶束的表面活性剂，Nagg)的所得颗粒(C12和C10NAN)。虽然C12和C10NAN的总细胞摄取效率相似，它们的细胞分布和局部运输存在差异，即使在确保两个颗粒的DNA总浓度相同之后。最终,随着时间的推移，C10NANs在细胞内出现较少弥漫性，与溶酶体的共定位较少，对所研究的目标基因实现更显著的敲除，表明更有效的内体逃逸。这些差异表明，表面活性剂的组装和拆卸性能，包括每个颗粒的表面活性剂的数量和CMC可以对DNA胶束和表面活性剂缀合物的细胞递送功效具有重要意义。
