Synthesis, Characterization, and Evaluation of Radical Scavenging Ability of Ellagic Acid-Loaded Nanogels

Ellagic acid (EA), a potential antioxidant phytochemical has low aqueous solubility and bioavailability. In this paper, encapsulation of ellagic acid has been carried out into the biodegradable disulfide crosslinked poly (ethylene glycol) PEO-based nanogels synthesized via AGET (activator generated electron transfer) ATRP (atom transfer radical polymerization), and their radical scavenging ability was evaluated. The encapsulation of the EA was carried out at two drug loading percentages, that is, 10 and 20 wt.% of the nanogels. 1,1-Diphenyl-2-picryldrazyl (DPPH) assay was utilized in order to assess the radical scavenging ability of the ellagic acid-loaded nanogels. A drug-loading level of about 2.5 wt.% was achieved with encapsulation efficiency of about 25% at 10 wt.% of the EA w.r.t nanogels, which was found to increase to about 4.7 wt.% with decreased encapsulation efficiency of 23.5% as EA content was increased to 20wt.% of the nanogels. Ellagic acid loading was found to be accompanied with increase in the size of the nanogels from 144.6 +/- 39.52nm for neat nanogels to 217.8 +/- 105.5 and 633 +/- 160.1 nm at 2.5 and 4.7 wt.% drug loading level. The nanogels were found to be capable of scavenging radicals and biocompatible on human cervical cancer cell lines (HeLa cells) at appropriate concentrations.