Optimized lentivirus-derived virus-like particles for efficient delivery of Cas9-based genome editors.

Implementation of therapeutic genome editing requires a potent, versatile, and transient delivery system to enable safe and effective in vivo applications. Here, we report on an optimized virus-like particle (VLP) platform for protein-based delivery of Cas9 ribonucleoproteins and Cas9-derived base editors and prime editors, termed LV-VLP-MA, that enables flexible editor deployment. By systematically engineering a panel of truncated Gag-Cas9 fusion variants, we identify a minimal MA-Cas9 configuration that maximizes editor packaging while effectively preserving efficient particle production and functional delivery. Systematic refinement of VLP production parameters enhances particle yield, supporting robust editing activity across diverse genomic targets. Importantly, systemic administration of LV-VLP-MA mediates efficient in vivo editing of the Pcsk9 locus with functional target suppression, establishing proof-of-concept for therapeutic application. Together, these results define a programmable, modular VLP-based platform that combines potency, flexibility, and transient delivery to expand the scope of in vivo genome engineering for therapeutic development.