Impact of the Core Chemistry of Self‐Assembled Spherical Nucleic Acids on their In Vitro Fate

• Published in: Angewandte Chemie 2023-12, Vol.135 (51), p.n/a
• Main Authors: Faiad, Sinan, Laurent, Quentin, Prinzen, Alexander L., Asohan, Jathavan, Saliba, Daniel, Toader, Violeta, Sleiman, Hanadi F.
• Format: Article
• Language: English
• Subjects: Antisense oligonucleotides; Antisense RNA; Biocompatibility; Cell surface receptors; Chemistry; Crosslinking; Deoxyribonucleic acid; Disulfide; DNA; Drug Delivery; Gene expression; Gene Silencing; Immune response; Nuclease; Nucleic acids; Oligonucleotides; Polymers; Proteins; Self-assembly; Serum proteins; siRNA; Spherical Nucleic Acids; Stimuli-Responsive
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202315768

Nucleic acid therapeutics (NATs), such as mRNA, small interfering RNA or antisense oligonucleotides are extremely efficient tools to modulate gene expression and tackle otherwise undruggable diseases. Spherical nucleic acids (SNAs) can efficiently deliver small NATs to cells while protecting their payload from nucleases, and have improved biodistribution and muted immune activation. Self‐assembled SNAs have emerged as nanostructures made from a single DNA‐polymer conjugate with similar favorable properties as well as small molecule encapsulation. However, because they maintain their structure by non‐covalent interactions, they might suffer from disassembly in biologically relevant conditions, especially with regard to their interaction with serum proteins. Here, we report a systematic study of the factors that govern the fate of self‐assembled SNAs. Varying the core chemistry and using stimuli‐responsive disulfide crosslinking, we show that extracellular stability upon binding with serum proteins is important for recognition by membrane receptors, triggering cellular uptake. At the same time, intracellular dissociation is required for efficient therapeutic release. Disulfide‐crosslinked SNAs combine these two properties and result in efficient and non‐toxic unaided gene silencing therapeutics. We anticipate these investigations will help the translation of promising self‐assembled structures towards in vivo gene silencing applications. In physiological conditions, self‐assembled spherical nucleic acids made from DNA amphiphiles encounter abundant serum proteins. Because they are held through weak non‐covalent interactions, they might disassemble, impacting their biological activity. Here, we investigate the biological fate of SNAs and the impact of core chemistry and stimuli‐responsive crosslinking on their stability, providing guidelines for the biological applications of these self‐assembled structures.