Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
ACS Nano. 2023 Sep 26;17(18):17996-18007. doi: 10.1021/acsnano.3c04333. Epub 2023 Sep 15.
The stability of the core can significantly impact the therapeutic effectiveness of liposome-based drugs. While the spherical nucleic acid (SNA) architecture has elevated liposomal stability to increase therapeutic efficacy, the chemistry used to anchor the DNA to the liposome core is an underexplored design parameter with a potentially widespread biological impact. Herein, we explore the impact of SNA anchoring chemistry on immunotherapeutic function by systematically studying the importance of hydrophobic dodecane anchoring groups in attaching DNA strands to the liposome core. By deliberately modulating the size of the oligomer that defines the anchor, a library of structures has been established. These structures, combined with and immune stimulation analyses, elucidate the relationships between and importance of anchoring strength and dissociation of DNA from the SNA shell on its biological properties. Importantly, the most stable dodecane anchor, (C12), is superior to the = 4-8 and 10 structures and quadruples immune stimulation compared to conventional cholesterol-anchored SNAs. When the OVA1 peptide antigen is encapsulated by the (C12) SNA and used as a therapeutic vaccine in an E.G7-OVA tumor model, 50% of the mice survived the initial tumor, and all of those survived tumor rechallenge. Importantly, the strong innate immune stimulation does not cause a cytokine storm compared to linear immunostimulatory DNA. Moreover, a (C12) SNA that encapsulates a peptide targeting SARS-CoV-2 generates a robust T cell response; T cells raised from SNA treatment kill >40% of target cells pulsed with the same peptide and 45% of target cells expressing the entire spike protein. This work highlights the importance of using anchor chemistry to elevate SNA stability to achieve more potent and safer immunotherapeutics in the context of both cancer and infectious disease.
核的稳定性会显著影响基于脂质体的药物的治疗效果。虽然球形核酸（SNA）结构提高了脂质体的稳定性，从而提高了治疗效果，但将 DNA 锚定到脂质体核的化学方法是一个探索不足的设计参数，具有潜在的广泛生物学影响。在此，我们通过系统研究将 DNA 链附着到脂质体核的疏水性十二烷锚定基团的重要性，来探索 SNA 锚定化学对免疫治疗功能的影响。通过故意调节定义锚的低聚物的大小，建立了一个结构库。这些结构与和免疫刺激分析相结合，阐明了锚定强度和 DNA 从 SNA 壳解离与生物特性之间的关系及其重要性。重要的是，最稳定的十二烷锚定物（C12）优于 = 4-8 和 10 结构，与常规胆固醇锚定的 SNA 相比，其免疫刺激增加了四倍。当 OVA1 肽抗原被（C12）SNA 包封并用作 E.G7-OVA 肿瘤模型中的治疗性疫苗时，50%的小鼠存活下来，并且所有存活下来的小鼠都能抵抗肿瘤再挑战。重要的是，与线性免疫刺激 DNA 相比，强烈的先天免疫刺激不会引起细胞因子风暴。此外，一种包封针对 SARS-CoV-2 的肽的（C12）SNA 会产生强烈的 T 细胞反应；从 SNA 治疗中产生的 T 细胞可以杀死>40%用相同肽脉冲的靶细胞和>45%表达整个刺突蛋白的靶细胞。这项工作强调了使用锚定化学提高 SNA 稳定性的重要性，以在癌症和传染病的背景下实现更有效和更安全的免疫疗法。
