Advancing Gene Editing Technologies with Spherical Nucleic Acids

Nanomaterials have already begun to play a pivotal role in overcoming the limitations of traditional drugs by enhancing drug delivery, improving bioavailability, overcoming biological barriers in the treatment and prevention of diseases. Spherical Nucleic Acids (SNAs) stand out as a versatile class of nanomaterials that have been utilized in applications spanning diagnostics and therapeutics. SNAs, comprised of a nanoparticle core densely functionalized with radially oriented oligonucleotides, offer unique advantages for nanomedicine. Their 3-dimensional structure renders SNAs with superior properties in comparison to linear nucleic acid molecules, including enhanced cellular uptake, resistance to nuclease degradation, and superior target affinity. These qualities make SNAs ideally suited for their application towards effective gene editing technologies. This presentation will cover two recent examples of employing SNAs in gene editing paradigms. First, an approach that enhances the therapeutic potential of small interfering RNAs (siRNAs) when formulated as SNAs is described. Until now, the gene silencing activity of SNAs had been hindered by endosomal entrapment. Here, a simple yet innovative strategy that employs calcium chloride (CaCl2) salting in SNA formulation results in enhanced cytosolic delivery and gene silencing activity by up to 20-fold across diverse cell lines, indicating a promising avenue for overcoming existing limitations. In a second, related story, SNAs are employed for the purposes of performing CRISPR/Cas9 systems for genome editing. In this work, Cas9 protein-cored SNAs, densely modified with DNA and preloaded with single-guide RNA, exhibit enhanced cellular uptake and stability, achieving notable genome editing efficiencies across multiple cell lines. The integration of GALA peptides and nuclear localization signals further enhances endosomal escape and nuclear localization. Taken together, this work underscores the importance of precise control over molecular interactions at the nanoscale and the potential of SNA-based nanotechnologies for gene editing applications. 

Learning Objectives:

• Spherical Nucleic Acids (SNAs), exhibit properties making them ideal constructs for nanomedicine and effective gene editing technologies. This talk describes routes of employing SNAs to markedly improve the cytosolic delivery of siRNAs and enhanced genome editing and delivery of CRISPR/Cas9 platforms.