Core-shell Magnetic Molecularly Imprinted Poly (Methyl Methacrylate) Nanoparticles: A Fast Tool for Physical Removal of Urea for Hemodialysis

Abstract Urea detection and elimination attracted great attention as a kind of representative toxin with the highest daily molar production for dialysis patients. Low molecular weight, high solubility, and low reactivity make it a challenge to absorb urea. Although there are different ways to for urea removal, there are some problems like causing side effects, being time-consuming, and wasting high amounts of absorbents. In the present research, urea adsorbents were prepared by synthesizing magnetic nanoparticles (Fe3O4 NPs) by co-precipitation method, functionalizing with SiO2 (Fe3O4@SiO2), and then modifying by surface imprinting poly (methyl methacrylate) with urea (MMIPs). The Fe3O4 and Fe3O4@SiO2 NPs were nearly spherical (5-20 nm in diameter) and in size. In 10 minutes, the MMIPs could absorb 50% of dialysate. The urea binding capacity of the system at the NP: Urea ratio of 0.5 and initial urea concentrations of 100 mg dL-1 were calculated at 1.06 mmol g -1 . Under the control of a pseudo-first-order equation, the adsorption process was determined. The Freundlich isotherm model was fitted to the equilibrium adsorption data. These MMIPs are proposed as promising tools for urea removal in hemodialysis to reduce dialysis time and improve patient compliance with the therapy and also for dialysate regeneration.