Nutcracker Therapeutics Announces Publication in ACS Nano Demonstrating the Therapeutic Viability of Nutshell Delivery Vehicles

Nutcracker Therapeutics, Inc. recently announced the publication of its latest peer-reviewed paper, which explores the fundamental aspects of its Nutshell platform of peptoid-based mRNA delivery vehicles. The paper, published in ACS Nano, outlines the design of these peptoids, their impact on mRNA expression, and comparisons to lipid nanoparticle (LNP) delivery vehicles.

mRNA vaccines and therapeutics are typically delivered using LNP formulations, which have known liver-bias and immunogenicity issues. Instead of using traditional lipids, Nutcracker Therapeutics chose peptoids as the macromolecule core of its technology. Peptoids are similar in structure to the peptides found ubiquitously in nature with a key difference: The side chain groups are attached to the amide nitrogen instead of the alpha carbon – a minor change with drastic implications for nanoparticle properties. Chief among these is the high level of tuning and customization that can be achieved by modifying the side chains of the peptoids, which can confer properties such as organ-targeting, increasing expression, and more.

This study sought to systematically characterize Nutcracker Therapeutics’ peptoid-based delivery vehicles and compare their performance to benchmark traditional LNPs. The scientists synthesized and characterized 221 different peptoid molecules, and clustered that library based on physico-chemical properties. The most promising cluster was then selected as a structural motif for further optimization. Ultimately, a high-expressing liver-targeted peptoid was identified which performed better than the benchmark lipid MC3 in inducing expression levels of an mRNA-encoded, anti-RSV protein in mice. Additionally, this peptoid showed limited reactogenicity in mice and was storage stable for longer than 6 months.

“As the mRNA therapeutics field expands, there is an increased need to understand and control delivery vehicle properties,” remarked Bette Webster, Senior Scientist and lead author on the study. “We demonstrate that peptoids are a flexible and modular replacement for ionizable lipids that facilitate tunable nanoparticles for a range of therapeutic areas. We build relationships between peptoid structure and in vivo expression that can be applied not only to the problem of IV delivery but also more focused applications.”

Additional findings from this paper include:

• Peptoid macromolecules can be further fine tuned to direct the localization of Nutshell delivery vehicles among the major target organs: lung, spleen, and liver
• Delivery of anti-RSV-encoding mRNA with peptoid-based Nutshell particles led to a roughly two-fold higher expression of the resulting protein 24 hours post-administration compared to MC3 at the same dose level
• Peptoids showed limited in vivo reactogenicity, based on serum levels of proinflammatory cytokines 6 hours post-administration in Balb/c mice. These markers of immunogenic response included interleukin-2, interleukin-6, TNF alpha, and interferon gamma
• Nutshell delivery vehicles were stable for six months in -80°C storage, with no growth in delivery vehicle diameter, changes in encapsulation, or impact to RNA integrity. The stored delivery vehicles did not show changes in protein expression, while also having several-fold higher expression versus stored MC3

“At Nutcracker Therapeutics, we believe that mRNA will be the modality of choice to treat a wide range of diseases – from the common to the exceedingly difficult. Unlocking this reality will require RNA-specific tools and processes,” commented Chief Scientific Officer Samuel Deutsch, PhD. “Our Nutshell delivery vehicles exemplify this philosophy, as we found ways to improve the current mRNA delivery paradigm, instead of relying on the same delivery tools employed throughout the industry. Each part of our platform – from the drug design process with the CodonCracker™ software, to the biochip-based Nutcracker Manufacturing Unit and Nutshell delivery vehicles – was built to simplify mRNA drug development, allowing us to create therapies with complex mechanisms and unique properties.”

The paper, titled Discovery of a peptoid-based nanoparticle platform for therapeutic mRNA delivery via diverse library clustering and structural parameterization, can be found online on the ACS Nano website.

Nutcracker Therapeutics, Inc. is an RNA therapeutics company that has combined the power of advanced engineering with high-precision biosynthesis to deploy a complete RNA platform that encompasses the design, delivery, and manufacturing of RNA medicines. Armed with this high-tech advantage, the company has initiated multiple therapeutic programs with the support of clinical investigators at leading institutions. Nutcracker Therapeutics’ technology platform has the potential to significantly reduce costs and cycle times for RNA therapeutic development, with dramatic advantages in speed and capacity scaling over other RNA manufacturing approaches. For more information, visit www.nutcrackerx.com.