Surface Engineering of Magnetite Nanoparticles with Boronated Polysaccharides Enables Alpha-1-Acid Glycoprotein...

Glycoproteins play essential roles in numerous biological processes, yet their controlled interaction with synthetic materials remains challenging due to structural complexity and heterogeneity of glycan moieties. In this study, starch-based magnetic nanomaterials functionalized with phenylboronic acid were developed and evaluated for pH-dependent interactions with α-1-acid glycoprotein (AGP). Dialdehyde starch (DAS) and carboxymethyl starch (CMS) were functionalized with phenylboronic acid to obtain DAS-PBA and CMS-PBA, which were subsequently used as coatings for magnetite nanoparticles, yielding the corresponding magnetic nanocomposites. The polymers and nanocomposites were comprehensively characterized using spectroscopic, microscopic, and thermal techniques. The functional accessibility of boronic acid groups was assessed using an Alizarin Red S assay. Binding studies demonstrated pH-dependent interactions with AGP, with enhanced binding observed under alkaline conditions, consistent with the behavior of boronic acid-diol interactions. Among the investigated systems, CMS-PBA-based materials exhibited higher AGP binding capacities compared to DAS-PBA-based analogues. Furthermore, partial release of AGP from the magnetic nanocomposites was achieved under mildly acidic conditions, confirming the reversible nature of the interactions.