Gallic acid loaded disulfide cross-linked biocompatible polymeric nanogels as controlled release system: synthesis, characterization, and antioxidant activity

In this article, a sustained release formulation of the antioxidant gallic acid (GA) is presented in the form of glutathione responsive disulfide cross-linked poly(ethylene glycol)-based nanogels synthesized via aqueous inverse miniemulsion using atom transfer radical polymerization. The particle size was found to be in the range from 227 +/- 51.78 to 573.3 +/- 207.2nm at three drug loading levels achieved i.e. 6.6, 14.26, and 18.29 wt.% of the nanogels with loading efficiency in the range of 6070%. The release profile of the GA studied at three drug loading levels suggested a controlled release and the nanogels were capable of scavenging radicals and retained the antioxidant activity. The GA-loaded nanogels were found to be biocompatible on human cervical cancer cell lines (HeLa). DCFH-DA (2,7-dichlorofluorescin diacetate) assay evidenced that the nanogels were capable of scavenging the reactive oxygen species in cellular environment.