Safer and efficient base editing and prime editing via ribonucleoproteins delivered through optimized lipid-nanoparticle formulationsRafał Hołubowicz, Samuel W. Du, Jiin Felgner et al.|Nature Biomedical Engineering|2024 Delivering ribonucleoproteins (RNPs) for in vivo genome editing is safer than using viruses encoding for Cas9 and its respective guide RNA. However, transient RNP activity does not typically lead to optimal editing outcomes. Here we show that the efficiency of delivering RNPs can be enhanced by cell-penetrating peptides (covalently fused to the protein or as excipients) and that lipid nanoparticles (LNPs) encapsulating RNPs can be optimized for enhanced RNP stability, delivery efficiency and editing potency. Specifically, after screening for suitable ionizable cationic lipids and by optimizing the concentration of the synthetic lipid DMG-PEG 2000, we show that the encapsulation, via microfluidic mixing, of adenine base editor and prime editor RNPs within LNPs using the ionizable lipid SM102 can result in in vivo editing-efficiency enhancements larger than 300-fold (with respect to the delivery of the naked RNP) without detectable off-target edits. We believe that chemically defined LNP formulations optimized for RNP-encapsulation stability and delivery efficiency will lead to safer genome editing.
Engineered nucleocytosolic vehicles for loading of programmable editorsAdvanced gene editing methods have accelerated biomedical discovery and hold great therapeutic promise, but safe and efficient delivery of gene editors remains challenging. In this study, we present a virus-like particle (VLP) system featuring nucleocytosolic shuttling vehicles that retrieve pre-assembled Cas-effectors via aptamer-tagged guide RNAs. This approach ensures preferential loading of fully assembled editor ribonucleoproteins (RNPs) and enhances the efficacy of prime editing, base editing, trans-activators, and nuclease activity coupled to homology-directed repair in multiple immortalized, primary, stem cell, and stem-cell-derived cell types. We also achieve additional protection of inherently unstable prime editing guide RNAs (pegRNAs) by shielding the 3'-exposed end with Csy4/Cas6f, further enhancing editing performance. Furthermore, we identify a minimal set of packaging and budding modules that can serve as a platform for bottom-up engineering of enveloped delivery vehicles. Notably, our system demonstrates superior per-VLP editing efficiency in primary T lymphocytes and two mouse models of inherited retinal disease, highlighting its therapeutic potential.
Data from: A combinatorial synthetic strategy for developing genome-editing protein-delivery agents targeting mouse retinaCRISPR/Cas9-based gene-editing technologies offer promise for treating inherited retinal diseases (IRDs); however, safe and efficient ocular delivery of precision editors remains challenging. To address this challenge, we report a new class of Coomassie brilliant blue (CBB)-derived lipidoids that bind and deliver proteins. Subretinal injection of Cre complexed with these lipidoids into mT/mG mice leads to robust recombination in the retinal pigment epithelium and photoreceptors. We employ the CBB-lipidoid platform to deliver adenine base editor (ABE) ribonucleoproteins (RNP). Incorporating CBB lipidoids into liposomes improves delivery efficiency. CBB11 stands out for facilitating precise in vivo ABE-mediated gene editing. Delivery of liposome-CBB11-RNP complexes results in a 120-fold increase in base editing compared to RNP alone and restores the scotopic ERG b-wave response in the rd12 mouse model. These results demonstrate the potential of CBB-augmented, liposome-RNP systems for therapeutic gene editing in the eye, paving the way for single-dose precision medicines to treat IRDs.
A combinatorial synthetic strategy for developing genome-editing protein-delivery agents targeting mouse retinaCRISPR/Cas9-based gene-editing technologies offer promise for treating inherited retinal diseases (IRDs), however safe and efficient ocular delivery of precision editors remains challenging. To address this challenge, we report a class of Coomassie brilliant blue (CBB)-derived lipidoids that bind and deliver proteins. Subretinal injection of Cre complexed with these lipidoids into mT/mG mice leads to robust recombination in the retinal pigment epithelium and photoreceptors. We employ the CBB-lipidoid platform to deliver adenine base editor (ABE) ribonucleoproteins (RNP). Incorporating CBB lipidoids into liposomes improves delivery efficiency. CBB11 stands out for facilitating precise in vivo ABE-mediated gene editing. Delivery of liposome-CBB11-RNP complexes results in a 120-fold increase in base editing compared to RNP alone and restores the scotopic ERG b-wave response in the rd12 mouse model. These results demonstrate the potential of CBB-augmented, liposome-RNP systems for therapeutic gene editing in the eye, paving the way for single-dose precision medicines to treat IRDs.