The design of lipid-based RNA delivery systems is often constrained by the limitations of vesicular architectures, which restrict passive RNA uptake and require complex encapsulation or transfection strategies. Here, we present a minimal lipid platform based on glycerol monodecanoate (GMD), where molecular chirality alone governs the formation of hydrated, non-vesicular mesophases capable of direct RNA uptake and retention.
GMD was synthesized in its R-, S-, and racemic forms, and their self-assembly behaviour was systematically evaluated. The R-enantiomer consistently formed sponge-like and bicontinuous cubic phases, while S- and racemic mixtures resulted in dense or disordered aggregates with poor RNA accessibility. RNA uptake was achieved by simple external addition of total yeast RNA, followed by incubation and analysis via fluorescence microscopy with RNA-selective dyes. Laurdan-based hydration profiling further confirmed the internal aqueous nature of R-GMD structures, correlating mesophase topology with RNA compatibility.
Interestingly, racemic GMD samples showed initial formation of dense phases, but over time transitioned into more hydrated morphologies, suggesting potential enantiomeric segregation or reorganization. However, these late-phase structures remained less effective in RNA uptake compared to the R-form, highlighting the functional relevance of chirality-controlled self-assembly.
This work demonstrates that chirality can act as a molecular switch to control lipid phase behaviour and functionality, even in simple single-chain amphiphiles. By bypassing the need for cationic lipids or vesicle encapsulation, this approach introduces a new direction for the design of minimal, tuneable RNA delivery platforms. These findings have implications for therapeutic nucleic acid delivery, where mesophase architecture and molecular symmetry can be exploited for efficient, passive RNA loading.