Researchers at Helmholtz Munich and the Technical University of Munich, led by corresponding authors Christoph Gruber, Florian Giesert, and Wolfgang Wurst, have developed synthetic RNA delivery vehicles using AI-designed protein assemblies, showing in preclinical experiments that the platform can outperform lipid nanoparticles (LNPs) in some cell systems and deliver CRISPR gene-editing cargo in patient-derived muscle cells and a pig model, according to a study published September 3, 2026 in Nature.
The platform, called Synthetic Transfer Vehicles (STVs), combines an AI-designed protein scaffold with membrane-binding, vesicle-release, and RNA-binding domains. The lead construct, STV-C8, forms approximately 110-nanometer vesicles that package RNA cargo and can be retargeted to different cell types using computationally designed receptor-binding proteins.
In HEK293T cells, STV-C8 required more than 10,000-fold less mRNA than LNPs formulated with the clinical ionizable lipid ALC-0315 to achieve equivalent reporter expression. The platform also delivered RNA into primary human monocytes, retinal organoids, and mouse astrocytes, cell types in which LNP performance was more limited.
For therapeutic proof-of-concept, STV-C8 delivered Cas9 mRNA and guide RNAs targeting dystrophin exon 51 into patient-derived skeletal muscle cells carrying a DMD-associated deletion, restoring the reading frame at the DNA level. The researchers also confirmed on-target editing after intramuscular administration in a single German Landrace pig, although the large-animal experiment was an initial proof-of-concept with n=1.
Additional experiments showed delivery of Cas13d RNA machinery into human lung cells, reducing SARS-CoV-2 replication, and delivery of Ascl1 mRNA with evidence of neuronal reprogramming activity.