Microfluidic Production of Exosome-Mimicking Lipid Nanoparticles for Enhanced RNA Delivery: Role of Exosomal Proteins.

Exosomes, which are cell-secreted lipid-based nanoparticles, play a crucial role in intercellular communication by encapsulating and delivering various biomolecules such as DNA, mRNA, miRNA, and proteins. They offer potential as drug delivery systems (DDSs) based on their ability to cross biological barriers, use natural communication mechanisms, and minimize immunogenicity. However, the heterogeneity of exosomes presents a bottleneck for functional analysis and the development of exosome-based DDSs. Therefore, engineering techniques are needed to produce exosomes or exosome-mimicking nanoparticles with controlled characteristics, including the presentation of specific exosomal proteins on their surface. Here, a one-step microfluidic method for producing exosome-mimicking lipid-based nanoparticles decorated with specific exosomal proteins was developed, enabling control over the composition and characteristics of the resulting exosomes. Exosome-mimicking nanoparticles decorated with tetraspanin proteins (CD9, CD63, CD81) and integrins (ITG αVβ5, ITG α6β4), which are involved in cell signaling and organ targeting, were thereby generated. Investigating the impact of these exosomal proteins on RNA delivery efficiency revealed that ITG αVβ5-decorated exosome-mimicking nanoparticles significantly enhance RNA delivery both in vitro and in vivo. This study provides an approach for producing precisely decorated exosome-mimicking nanoparticles, which may be applied to elucidate the functions of exosomal proteins and develop targeted DDSs.