Chitosan-based glycated polyampholyte nanogels for copper-catalysed Fenton-like reaction†

Abstract

For several decades, there has been great interest in the application of polysaccharide nanogels as nanoscale platforms that integrate polymer scaffolds to confer distinctive biochemical properties. Notably, nanogels, utilizing metal coordination as an efficient cross-linking strategy to enhance structural integrity and responsiveness, have emerged as nanoscale catalysts, broadening their utility in controlled drug delivery, sensing, and biomedical applications. In this study, we present a facile method for preparing chemically modified nanogels based on chitosan, facilitated by Cu(II) coordination for a Fenton-like reaction. The chitosan scaffold undergoes modifications through ethylenediaminetetraacetate (EDTA) conjugation and non-enzymatic glycation, yielding water-soluble structures across a wide pH range. Cu(II) chelation facilitates coordination-mediated cross-linking, resulting in the formation of nanogels with multiple Cu(II)-chelated domains that resemble artificial enzymes. The resulting Cu(II)-containing nanostructures exhibit altered catalytic activity attributed to the distinctive chemical environment of self-folded polysaccharide scaffolds. Spectroscopic monitoring reveals different kinetic pathways in Cu(II)-catalysed Fenton-like reactions mediated by self-folded polysaccharide-based nanostructures containing Cu(II)-chelating active sites. These results demonstrate the potential of polysaccharide nanogels as advanced materials with versatile functionalities in catalytic applications.