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-FeO (QX-FeO) core/shell nanocomposites and explore their potential application in the biomedical fields. γ-FeO 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-FeO and FA-QX-FeO nanoparticles. An obvious strong absorption of γ-FeO at 580 cm in the spectra of QX-FeO is observed, the Fe element content of QX-FeO is 30-75 μg/mL and the saturation magnetization of QX-FeO nanoparticles is 1.49 emu/g. The γ-FeO and QX-FeO nanoparticles are of regular sphericity with diameter of 50-100 nm and 60-150 nm, respectively. The highest zeta potential of QX-FeO nanoparticles is -41 mV, and the PLL-QX-FeO nanoparticles have a positive potential with a maximum value of 45.2 mV. In addition, FA-QX-FeO showed excellent performance in T-weighted Magnetic Resonance (MR) imaging with an r value of 190 mMS. Each nanocomposite has its own inherent properties, which contributes to its versatile utilization and application potential.