Magnetic mesoporous silica/ϵ-polylysine nanomotor-based removers of blood Pb²⁺

The removal of excessive blood lead ions (Pb2+) is very important to human health, but current effective removal technology is still lacking because of the complex existence state of Pb2+ in blood, which can be attributed to the fact that most of the blood Pb2+ is combined with haemoglobin (Hb) located in red blood cells (RBCs). Here, a new type of magnetic mesoporous silica/ϵ-polylysine nanomotor-based remover (MMS/P NR) with abundant chelation sites was designed, synthesized and used to remove Pb2+ from blood. The magnetic core can make the nanocomposites become nanomotors with autonomous movement under an external variable magnetic field, which can effectively improve the contact probability between the MMS/P NRs and Pb2+-contaminated Hb in RBCs. The amino rich ϵ-polylysine (ϵ-PL) was used as the co-template of mesoporous silica. Mesoporous channels can provide a confinement effect for Pb2+-contaminated Hb to stabilize the captured blood Pb2+. The movement behavior of the MMS/P NRs in and out of RBCs and the capture mechanism of Pb2+ in the blood were studied. The results indicate that the MMS/P NRs we propose have good blood compatibility, low cytotoxicity, magnetic properties, autonomous movement ability and recyclability under the condition of an external magnetic field. Moreover, compared with the experimental conditions without an external variable magnetic field (0.01485 mg g-1), the MMS/P NRs show a higher blood Pb2+ removal ability under the condition of an external variable magnetic field (0.05525 mg g-1). The design strategy of this remover based on nanomotor technology has great potential in the future medical treatment of heavy metal poisoning.