The Generation And Assessment Of Iron Chelating Polymeric Micelles

Iron overload is the main reason of hemochromatosis,and it can cause cirrhosis,diabetes,cardiomyopathy and other diseases.Deferiprone,deferoxamine,deferasirox and other iron chelating agents have several obstacles in the removal of excess iron from the human body,such as the adverse effects,short half life and frequent dosing.It was postulated that the use of nanocarriers can enhance the iron chelating ability and address the above-mentioned issues.We designed and synthesized the macromolecular iron chelator mPEG-P（Glu-CP）in this work,where the macromolecule mPEG-poly-（glutamic acid）（mPEG-P（Glu））copolymer served as drug carrier.The mPEG-P（Glu-CP）was synthetized by the reaction of amidation,combining together the mPEG-P（Glu）with 1-（2-aminoethyl）-3-hydroxy-2-methyl-4-pyridinone.The synthetic products were verified by ¹H NMR,¹³C NMR and MS.The different polymeric micelles of mPEG-P（Glu-CP）and mPEG-P（Glu-CP）-Fe³⁺were achieved by the method of dialysis.The particle size,surface morphology and the particle stability of the nanoparticles were characterized by the methods of dynamic light scattering（DLS）,transmission electron microscope（TEM）.The hydrodynamic size of the micelles of mPEG-P（Glu-CP）and m PEG-P（Glu-CP）-Fe³⁺was 170.5±14.3 nm and 100.3±6.9 nm,respectively.The zeta potential of the micelles of mPEG-P（Glu-CP）and mPEG-P（Glu-CP）-Fe³⁺was-15.4±1.4 mV and-27.6±3.0m V,respectively.The results showed that iron chelating made the micelles crosslink closely and shrink.TEM showed that the polymeric micelles were spherical and well distributed with 123.6±24.7 nm和66.7±10.8 nm.A systematic comparative evaluation of the 1-（2-aminoethyl）-3-hydroxy-2-methyl-4-pyridinone（CP-NH₂）and mPEG-P（Glu-CP）on the ability of removing excess iron in vitro was well performed via UV-vis and atomic absorption spectrum（AAS）quantification methods,respectively.The chelating ratio of CP-NH₂ and mPEG-P（Glu-CP）was 3.2±0.2 and2.4±0.3,respectively.The superior chelating ability of mPEG-P（Glu-CP）was demonstrated.The chelating ability was demonstrated in the mouse embryonic fibroblast cells（3T3 cells）,and the iron scensitive probe-calcein fluorescein（Calcein-AM）was used as an indicator.The polymeric micelle of mPEG-P（Glu-CP）could eliminate more iron than DFP in the cells.The cell viability analysis showed that both deferrone（DFP）and mPEG-P（Glu-CP）had less toxic effects on 3T3 cells.This study had shown the macromolecular iron chelating mPEG-P（Glu-CP）could remove more excess iron than the small molecular iron chelator.This nanoscale iron chelators may present an efficient approach for iron overload disease treating.