Neonatal Fc receptor-targeted lignin-encapsulated porous silicon nanoparticles for enhanced cellular interactions and insulin permeation across the intestinal epithelium.

Oral insulin delivery could change the life of millions of diabetic patients as an effective, safe, easy-to-use, and affordable alternative to insulin injections, known by an inherently thwarted patient compliance. Here, we designed a multistage nanoparticle (NP) system capable of circumventing the biological barriers that lead to poor drug absorption and bioavailability after oral administration. The nanosystem consists of an insulin-loaded porous silicon NP encapsulated into a pH-responsive lignin matrix, and surface-functionalized with the Fc fragment of immunoglobulin G, which acts as a targeting ligand for the neonatal Fc receptor (FcRn).