GalNAc-CPP conjugates improve the efficiency of oligonucleotide drugs in vivo

Antisense oligonucleotides (ASOs) have emerged as a promising therapeutic strategy, enabling targeted modulation of gene expression through mechanisms such as exon skipping, exon inclusion, and transcript degradation. However, low cellular uptake, limited control over ASO trafficking, and various intracellular barriers compromise both active efficacy and clinical translation. The two primary mechanisms of action for ASOs both function within the nucleus. Splice-switching ASOs directly modulate pre-mRNA splicing, whereas mRNA-degrading ASOs rely on RNase H, an enzyme predominantly localized and active within the nucleus. Therefore, effective nuclear delivery of ASOs is essential to achieve maximum therapeutic efficacy. In this study, cell-penetrating peptides (CPP) were conjugated with triantennary N-acetyl galactosamine (GalNAc, GN3) to develop a hepatocyte-targeted oligonucleotide delivery system. The resulting conjugates enhanced delivery efficiency for both fluorescent dyes and ASOs. This work may provide an effective strategy for the design and development of hepatocyte-nuclear-targeted drug delivery systems.