Figure 1. iRGD-enhanced tumor accumulation of silicasome-encapsulated drugs.

Intravenous iRGD penetrates tumor tissue in a 3-step process. First, iRGD binds to α_v integrins. Second, protease cleavage of bound iRGD generates a C-terminal CendR–containing fragment of iRGD at the tumor site. Third, CendR fragment binds to NRP-1, which promotes silicasome uptake and transcytosis through the vessel endothelium, allowing delivery of cargo directly to the target tumor.