Fe₃O₄ Nanoparticles Coated with Mesoporous Shells for Pb(II) Removal from Blood

The current difficulty in treating blood lead poisoning lies in effectively removing Pb(II), which is mainly located inside red blood cells (>95%) and is complexed with hemoglobin, without causing damage to the blood environment. In this work, a new type of blood nanoremover that can safely enter red blood cells to remove the Pb(II) located in the cells is reported. Specifically, using tetraethyl orthosilicate (TEOS) as the silicon source, a silica shell with a mesoporous pore size of about 30 nm was synthesized on the outer surface of Fe3O4 nanoparticles, resulting in Fe3O4/mSi with flower morphology. Then, dimercaptosuccinic acid (DMSA) with good affinity to Pb(II) was modified inside the pores of the silica shell to obtain Fe3O4/mSi/D. The experimental results showed that the size of the synthesized Fe3O4/mSi/D was relatively uniform, and the pore structures were regular. Fe3O4/mSi/D would not cause obvious hemolysis and coagulation in the blood, and they could avoid the phagocytosis of the immune system and enter the red blood cells. The removal efficiency of Pb(II) by Fe3O4/mSi/D can reach about 73.5% in 30 min. This strategy provides the possibility for the removal of heavy metals in blood.