Targeting siRNA nanoparticles with ApoB peptide: Formulation, biodistribution, and bioactivity in pancreatic tumor-bearing mice

Pancreatic cancer (PC) is one of the most lethal cancers, with limited therapeutic means mainly due to its distinctive extracellular matrix (ECM). Polymeric nanoparticles (NPs) containing siRNA against VAV1 protein, which is overexpressed and involved in PC progression and metastases formation, have been shown as a promising approach. For enhanced tumor accumulation of the siRNA and effective therapy, targeted NPs is a valuable approach. Herein, poly(lactic-co-glycolic acid) (PLGA)-based NPs encapsulating siVAV1 were linked with an ApoB-derived peptide. This targeting ligand possesses a high affinity for proteoglycans and low-density lipoprotein receptors, which are overexpressed on the PC cell surface and within the ECM. We have characterized the physicochemical properties of ApoB-targeted NPs (T-NPs), examined their affinity properties in 2D/3D cell cultures, and assessed their biodistribution and therapeutic bioactivity in an orthotopic PC mouse model. T-NPs displayed favorable physicochemical properties in terms of nano-size, low polydispersity index, neutral charge, homogenous spherical morphology, and efficient siRNA encapsulation. High affinity and increased internalization of T-NPs were observed in cell cultures. Treatment of PC-bearing mice with siVAV1-laden T-NPs revealed superior tumor accumulation, resulting in increased survival rates following significant suppression of tumor growth and metastases. The therapeutic effect was mediated via the knockdown of both VAV1 mRNA and protein levels. These findings validate our hypothesis that targeted ApoB-PLGA NPs can address PC therapeutic challenges, suggesting an effective and safe targeting approach.