Targeted Intracellular Delivery via Precision Programming of ARRDC1-Mediated Microvesicles.

Efficient and cell-specific delivery remains a major barrier to realising the full therapeutic potential of modalities such as mRNA and CRISPR-based gene editors. Here, we report a versatile delivery platform based on engineered ARRDC1-mediated microvesicles (ARMMs) capable of delivering cargo to defined cell populations. By decorating ARMMs with engineered Nipah virus (NiV)-derived fusion and attachment proteins conjugated to cell-specific ligands, we enable selective binding and membrane fusion-mediated cargo release. ARMMs functionalized with anti-CD8 single-chain variable fragment (scFv) delivered protein, mRNA, or CRISPR-Cas9 base editor selectively to CD8⁺ T cells. Similarly, ARMMs displaying a designed ankyrin repeat protein (DARPin) targeting the GluA4 receptor enabled delivery to parvalbumin-positive (PV⁺) neurons. In vivo, administration of targeted ARMMs resulted in functional delivery to CD8⁺ splenocytes and PV⁺ cortical neurons in mice. These findings establish surface-engineered ARMMs as a programmable and modular system for precision delivery of therapeutic macromolecules, with broad applicability in gene and RNA-based medicine.