International journal of molecular sciencesSep 15, 2026

Using Genetic Code Expansion to Attach Targeting Proteins to Lipid Nanoparticles for Selective mRNA Delivery to CD8+ T Cells

mRNA Technology Weekly Brief ↗PubMed ↗DOI ↗OA ↗

Updated Sep 16, 2026

Abstract

Targeted lipid nanoparticles successfully transfected CD8⁺ T-lymphocytes in vitro.

Lipid nanoparticles (LNPs) have limitations in targeting specific cell populations due to a lack of specificity.
An innovative method was developed to create targeted LNPs through the post-insertion of protein-lipid conjugates.
A single amino acid, p-azido-L-phenylalanine, was incorporated into a binding protein to enable functionalization of the LNP surface.
Characterization of the DARPin-LNP showed that particle size was preserved and a negative charge was acquired after the insertion.
In vitro tests demonstrated that these targeted LNPs selectively delivered nucleic acids to cytotoxic lymphocytes.

Simplified

Lipid nanoparticles (LNPs) are an effective platform for delivering therapeutic payloads, but their use for targeting specific cell populations in vivo is limited by a lack of specificity. To address this issue, we developed an innovative approach for creating targeted LNPs based on the post-insertion of protein-lipid conjugates. By expanding the genetic code, a single p-azido-L-phenylalanine residue was specifically incorporated into a DARPin against murine CD8, enabling copper-free click-chemistry with dibenzocyclooctyne (DBCO) to functionalize the particle surface with DARPin conjugates. DARPin-LNP characterization demonstrated preservation of particle size and acquisition of a characteristic negative charge after DARPin insertion, confirming successful post-insertion. In vitro experiments using primary murine splenic T-cells showed that targeted LNPs selectively transfected CD8⁺ T-lymphocytes. These data indicate that the developed platform enables selective in vitro delivery of nucleic acids to cytotoxic lymphocytes, highlighting its potential relevance for designing safer immunotherapeutic strategies.