From RNA to DNA: How Cargo Identity Reprograms Lipid Nanoparticle Architecture and Function

Lipid nanoparticles (LNPs) have become the leading platform for delivering genetic material, gaining global recognition through the success of mRNA-based COVID-19 vaccines such as mRNA-1273 (SpikeVax, Moderna) and BNT162b2 (Comirnaty, BioNTech/Pfizer). Yet, while RNA-LNPs have reached clinical maturity, their DNA counterparts remain comparatively underexplored, despite holding great promise for gene replacement and genome-editing therapies. In this review, we turn the spotlight on DNA-loaded LNPs, examining how their structure, composition, and biological behavior differ from RNA-LNPs, their natural point of reference, and from earlier lipid-based systems such as cationic liposome/DNA complexes (lipoplexes). DNA-LNPs tend to form larger, more heterogeneous, and often multilamellar particles due to the intrinsic stiffness and high charge density of DNA. These distinctive features call for dedicated design strategies, including the use of cationic lipids, pre-condensation agents, and optimized PEGylation schemes. Moreover, DNA profoundly influences the biomolecular corona that forms in biological fluids, which in turn shapes immune recognition, circulation, and tissue targeting. By highlighting these unique physical and biological challenges, this review underscores the need to move beyond simply adapting RNA-based formulations. Instead, a cargo-informed design approach will be key to unlocking the full therapeutic potential of DNA-LNPs in next-generation gene delivery.