Peptide nanomicelles for NIR light-dependent siRNA delivery

The peptide amphiphile PA8, derived from the GAVILRR peptide, was developed as a carrier for small interfering RNA (siRNA) delivery; however, its RNA interference (RNAi) efficacy was limited owing to predominant endocytotic uptake. In this study, the RNAi efficiency of PA8 nanomicelle/siRNA complexes was enhanced by modifying the nanomicelles with the photosensitizer DY750 and the tumor-homing peptide iRGD. The conjugation of DY750 to the nanomicelles facilitated endosomal escape of the nanomicelle/siRNA complexes, enabling the cytosolic release of siRNA. Additionally, the incorporation of iRGD improved RNAi delivery efficiency in the AsPC-1 pancreatic ductal adenocarcinoma cell line. PA8-DY750-iRGD nanomicelle complexes loaded with siRNA against polo-like kinase 1 (PLK1) achieved an 80% reduction in PLK1 mRNA levels in AsPC-1 cells and a moderate 28% knockdown in NCI-N87 gastric cancer cells. Notably, no RNAi effect was observed in noncancerous 1C3D3 pancreatic cells or HEK293T kidney cells, underscoring the selectivity of this system for AsPC-1 cells. These findings highlight the potential of PA8-DY750-iRGD nanomicelle complexes as a targeted therapeutic platform for specific cancers, particularly pancreatic cancer.