Synthetic nanoparticles for cell-type specific, spatially resolved loading and export of MiRNAs in neural cells

Background: Brain development and plasticity depend on specific microRNA (miRNA) expression patterns across cell types and subcellular compartments. Nevertheless, comprehensive profiling of localized brain miRNAs is still limited by challenges in isolating individual cell types or compartments and in detection sensitivity. Results: To overcome these limitations, we advanced HIV-1 Gag's ability to bind host miRNAs within Virus-like Particles to develop Synthetic Nano-Particles for Precise endogenous miRNA loading and export (SNaP). Our data establish SNaP's modularity and portability to clinically relevant neural cells, with particle yields matching benchmark packaging cells. The integration of SNaP with a cell-specific promoter enabled lineage-restricted miRNA export, while incorporating a dendritic localization signal improved the specificity of post-synaptic miRNA recovery over traditional synaptosomes. Additional engineering with a miRNA-binding module synergistically increased synaptic miRNA packaging in a sequence-independent manner. Conclusion: Collectively, this work positions SNaP as a technological advancement supporting the high-resolution, spatially resolved profiling of miRNAs, adaptable to diverse polarized or heterogeneous culture systems.