Modulating the Protein Corona on Nanoparticles by Finely Tuning Cross-Linkers Improves Macrophage Targeting in Oral Small Interfering RNA Delivery

The protein corona (PC) plays an important role in regulating the in vivo fate of nanoparticles (NPs). Modulating the surface chemical properties of NPs to control PC formation provides an alternative impetus for the oral delivery of small interfering RNA (siRNA). Herein, using tripolyphosphate (TPP), hyaluronic acid, and poly-γ-glutamic acid as cross-linkers, three types of mannose-modified trimethyl chitosan-cysteine (MTC)-based NPs with distinct surface chemistries were prepared to encapsulate siRNA via ionic gelation. The MTC-based NPs that were cross-linked exclusively with TPP (MTC/TPP/siRNA NPs) exhibited greater thiol group accessibility on their surfaces, resulting in a stronger affinity for apolipoprotein (APO) B48 during translocation across intestinal epithelia. Moreover, intracellular transport of MTC/TPP/siRNA NPs via the endoplasmic reticulum and Golgi apparatus further increased adsorption of APOB48, a key component of chylomicrons, which follow a similar transport pathway. Benefiting from the elevated APOB48 levels within the PC, the orally delivered MTC/TPP/siRNA NPs showed higher uptake by hepatic macrophages and better therapeutic efficacy for acute liver injury. Our results elucidate the role of NP surface chemical characteristics and translocation mechanisms across intestinal epithelia in forming oral PC, providing valuable insights for designing NPs that achieve effective oral gene delivery by customizing PC formation in vivo.