Transport Mechanisms of Butyrate Modified Nanoparticles: Insight into “Easy Entry, Hard Transcytosis” of Active Targeting System in Oral Administration

The intestinal epithelium constitutes a major barrier for orally delivered nanoparticles (NPs). Although surface ligand modification can increase cellular uptake of NPs, the transepithelial transport of active targeting NPs is relatively limited. The phenomenon is described as “easy entry, hard transcytosis”. However, underlying mechanisms and potential solutions of this phenomenon are unclear. Here, butyrate modified polyethylene glycol coated...