Common mRNA delivery systems include:

• Liquid nanoparticles (LNPs)are spherical nanoparticles composed of lipids that encapsulate mRNA molecules. They protect the mRNA from degradation and facilitate its entry into cells. 
• Polymeric nanoparticles use polymers such as polyethylenimines to form complexes with mRNA. 
• Free mRNAcan also be delivered in its naked form without encapsulation. However, it is generally less effective at protecting mRNA and facilitating cell entry compared to encapsulated systems.
• Cationic peptide-based carriers(often with cell-penetrating capabilities) are used to condense and deliver mRNA. Peptide-based carriers can form complexes with mRNA through electrostatic interactions and may enhance cellular uptake by disrupting endosomal membranes.
• Dendritic cell-based deliveryinvolves injecting dendritic cells ex vivo with mRNA and then administering them into the host.
• Some delivery systems use inorganic materialslike gold or silica nanoparticles to carry mRNA.