pH-triggered poly(ethylene glycol) nanogels prepared through orthoester linkages as potential drug carriers

The new acid-labile poly(ethylene glycol) (PEG) nanogels were prepared by copolymerization of a new crosslinking agent containing orthoester groups (OEAM) and methoxypolyethylene glycol acrylate (MPEGAC). DOX was loaded into PEG nanogels with a loading content of 18.2%, which was highly desirable for targeted cancer therapy without premature drug release in neutral environment. The cellular uptake and cytotoxicity of DOX-loaded PEG nanogels were measured using SH-SY5Y and HepG2 cells. Tumor penetration and antitumor activity were investigated using SH-SY5Y tumor-like spheroids. All results demonstrate that the pH-sensitive PEG nanogels may be used as potential drug carriers for chemotherapy.