Table 3.
Delivery strategies of mRNA vaccines.
| Delivery strategies | Structure | Study findings | References |
|---|---|---|---|
| Lipid-based | |||
| 3-Comp | Composed of nAcx-Cm lipids, permanent cationic lipids, and PEG lipids | Better delivery efficiency and lung targeting than four- or five-component systems containing cholesterol and phospholipids, while still maintaining nanoparticle stability | [77] |
| 4N4T LNP (4-Comp) | Composed of multicharged lipids with 4N4T, cholesterol, phospholipids, and PEG | Providing enhanced mRNA delivery, robust immune responses, and improved safety compared to traditional LNP systems | [78] |
| Inhalable LNP (5-Comp) | Composed of ionizable lipids, helper lipids, phospholipids, and PEG | The iLNP formulation is more suitable for inhalation and respiratory disease treatments because it can form effective and intact aerosolized particles. | [79] |
| Polymer-based | |||
| F-PEI-based nanoparticle | Composed of a F-PEI shell and an mRNA core | Effective delivery of mRNA vaccines to exert anti-tumor effects without the need for adjuvants. | [22] |
| PEG-Plys-based nanoparticles | Composed of polyethylene glycol-polylysine (PEG-PLys) modified with triphenylphosphonium | Significantly extended blood circulation time and increased mRNA distribution within solid tumors | [83] |
| Anionic polymers nanoparticles | Composed of a PLGA shell and an mRNA core | Achieved a delivery efficiency of up to 80%, rapidly inducing protein translation | [84] |
| VLP-based | |||
| Chimeric VLP | Composed of antigen-encoding mRNA, unmethylated CpG oligonucleotides, and positively charged proteins within a phospholipid bilayer. | Exerting adjuvant effects through structural modifications to elicit potent humoral and cellular immunity in prophylactic vaccines against HPV, cervical cancer, and breast cancer | [86–89] |
CpG: Cytosine-phosphorothioate-guanine; F-PEI: Fluoroalkane-modified polyethylenimine; iLNP: Inhalable LNP; LNP: Lipid nanoparticle; mRNA: Messenger RNA; PEG: Polyethylene glycol; PEG-PLys: PEG-poly(l-lysine); PLGA: Poly(lactic-co-glycolic acid); VLP: Virus-like particle; 3-Comp: Three-component LNP; 4N4T: Four tertiary amine nitrogen atoms.