pH-degradable PVA-based nanogels via photo-crosslinking of thermo-preinduced nanoaggregates for controlled drug delivery.

pH-Degradable PVA nanogels, which are prepared by photo-crosslinking thermo-preinduced PVA nanoaggregates in water without any surfactants or toxic organic solvents, are used for intracellular PTX release and anticancer treatment. These nanogels fast degraded at mildly acidic conditions with a pH-triggered PTX release, and the degradation products are only native PVA and poly(hydroxyethyl acrylate) (PHEA) as well as acetaldehyde without any toxic byproducts. The nanogel sizes could be tailored by different temperatures during the crosslinking process. The results of confocal microscopy and flow cytometry revealed that smaller nanogels exhibited enhanced internalization with MCF-7 cells than the ones treated with larger nanogels, by which the smaller PTX-loaded nanogels induced a more significant cytotoxicity against MCF-7 cells. GRAPHIC ABSTRACT: pH-Degradable PVA nanogels can be prepared by photo-crosslinking of thermo-preinduced nanoaggregates with tailored nanogel sizes given their pH-triggered PTX release and fast acid-degradation into native PVA and cell-compatible poly(hydroxyethyl acrylate) (PHEA) as well as acetaldehyde.