Smart pH-sensitive nanoassemblies with cleavable PEGylation for tumor targeted drug delivery.

A new acidly sensitive PEGylated polyethylenimine linked by Schiff base (PEG-s-PEI) was designed to render pH-sensitive PEGylation nanoassemblies through multiple interactions with indomethacin and docetaxel (DTX). DTX nanoassemblies driven by PEG-s-PEI thus formulated exhibited an excellent pH-sensitivity PEGylation cleavage performance at extracellular pH of tumor microenvironment, compared to normal tissues, thereby long circulated in blood but were highly phagocytosed by tumor cells. Consequently, this smart pH-sensitive PEGylation cleavage provided an efficient strategy to target tumor microenvironment, in turn afforded superior therapeutic outcome in anti-tumor activity.