Synthesis and characterization of biofunctional quaternized xylan-Fe2O3 core/shell nanocomposites and modification with polylysine and folic acid

Abstract The aims of this study are to prepare quaternized xylan-Fe 2 O 3 (QX-Fe 2 O 3 ) core/shell nanocomposites and explore their potential application in the biomedical fields. γ-Fe 2 O 3 nanoparticles synthesized by a facile solvothermal process are coated with QX via reverse microemulsion method and further modified by polylysine (PLL) and folic acid (FA) to prepare PLL-QX-Fe 2 O 3 and FA-QX-Fe 2 O 3 nanoparticles. An obvious strong absorption of γ-Fe 2 O 3 at 580 cm −1 in the spectra of QX-Fe 2 O 3 is observed, the Fe element content of QX-Fe 2 O 3 is 30–75 μg/mL and the saturation magnetization of QX-Fe 2 O 3 nanoparticles is 1.49 emu/g. The γ-Fe 2 O 3 and QX-Fe 2 O 3 nanoparticles are of regular sphericity with diameter of 50–100 nm and 60–150 nm, respectively. The highest zeta potential of QX-Fe 2 O 3 nanoparticles is −41 mV, and the PLL-QX-Fe 2 O 3 nanoparticles have a positive potential with a maximum value of 45.2 mV. In addition, FA-QX-Fe 2 O 3 showed excellent performance in T 2 -weighted Magnetic Resonance (MR) imaging with an r 2 value of 190 mM −1 S −1 . Each nanocomposite has its own inherent properties, which contributes to its versatile utilization and application potential.