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

The aims of this study are to prepare quaternized xylan-Fe2O3 (QX-Fe2O3) core/shell nanocomposites and explore their potential application in the biomedical fields. gamma-Fe2O3 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-Fe2O3 and FA-QX-Fe2O3 nanoparticles. An obvious strong absorption of gamma-Fe2O3 at 580 cm(-1) in the spectra of QX-Fe2O3 is observed, the Fe element content of QX-Fe2O3 is 30-75 mu g/mL and the saturation magnetization of QX-Fe2O3 nanoparticles is 1.49 emu/g. The gamma-Fe2O3 and QX-Fe2O3 nanoparticles are of regular sphericity with diameter of 50-100 nm and 60-150 nm, respectively. The highest zeta potential of QX-Fe2O3 nanoparticles is -41 mV, and the PLL-QX-Fe2O3 nanoparticles have a positive potential with a maximum value of 45.2 mV. In addition, FA-QX-Fe2O3 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.