Targeted delivery of cytotoxic proteins via lipid-based nanoparticles to primary Langerhans cells

Targeted delivery has emerged as a critical strategy in the development of novel therapeutics. The advancement of nanomedicine hinges on the safe and precise cell-specific delivery of protein-based therapeutics to the immune system. However, major challenges remain, such as developing an efficient delivery system, ensuring specificity, minimizing off-target effects, and attaining effective intracellular localization. Our strategy utilizes lipid-based nanoparticles conjugated with a glycomimetic ligand. These nanoparticles selectively bind to langerin, a C-type lectin receptor expressed on Langerhans cells in the skin. We opted for cytotoxic proteins, namely cytochrome c and saporin, as model proteins to showcase the potential of delivering intact proteins to Langerhans cells. These proteins are recognized for their ability to induce apoptosis upon entry into the cytosol. We observed specific killing of cells expressing langerin in vitro, and in primary Langerhans cells isolated from mouse and human skin ex vivo with minimal off target effects. By delivering functional proteins within lipid nanoparticles to Langerhans cells, our approach offers new potential to deliver effective therapeutics with minimal side effects.