Revolutionary mRNA vaccine delivery targets lymph nodes for better cancer treatment
Scientists have created a new way to deliver mRNA vaccines that targets lymph nodes with precision. The method uses modified polyplexes to carry the vaccine directly to immune cells, improving effectiveness. This breakthrough could make cancer vaccines more reliable and easier to administer. Traditional mRNA cancer vaccines often fail because they don’t reach lymph nodes efficiently. Instead, they build up in organs like the liver, reducing their impact and increasing side effects. The new system solves this by using a polyplex made of mRNA and a specially altered low-molecular-weight polyethylenimine (PEI) with cyclic disulfide monomers.
These cyclic disulfides bind specifically to the transferrin receptor on monocytes—a type of white blood cell. Once injected under the skin, the polyplexes trigger an innate immune response and attract monocytes to the injection site. The monocytes then act as carriers, transporting the vaccine to nearby lymph nodes, where they help launch a targeted adaptive immune attack. Tests in multiple tumour models have shown promising results. Using antigens like Survivin, HPV-derived peptides, ovalbumin, and interleukin-12 (IL-12) mRNA, the system slowed melanoma growth and blocked metastasis. The subcutaneous injection method also makes the treatment more practical for routine clinical use.
The new delivery system cuts down on off-target liver uptake, lowering toxicity and improving patient comfort. By ensuring mRNA vaccines reach lymph nodes effectively, it could enhance cancer immunotherapy outcomes. Further studies will determine its broader applications in treating different tumour types.
