Preliminary Study On The Influence Of Gold Magnetic Nanoparticles With Different Structure Morphology And Components On The Activity And Function Of Macrophages

Magnetic nanoparticles have unusual magnetic properties as well as the properties of common nanomaterials which are widely used in biological fields such as biological magnetic resonance imaging,nucleic acids assays,targeted drug delivery system,cell isolation and enzyme immobilization;Gold magnetic nanoparticles are composite nanomaterials consisting of Fe₃O₄and gold,the gold provide the composite material plasmon resonance absorption,highly efficient coupling molecules,and good biocompatibility,and Fe₃O₄ensure this nanomaterial could be isolated under a magnetic field.In view of these excellent properties,gold magnetic nanoparticles have drawn great attention in the field of biomedicine has become more extensive and in recent years has become a research focus.In addition,macrophages play an important role in nonspecific defense?innate immunity?and specific defense?cellular immunity?in vertebrates.Research shows that when nanoparticles could be absorb and swallow by macrophages,which compromise the function of magnetic nanoparticles in the body.Therefore,mouse monocyte macrophage RAW 264.7 was selected to study the interaction between magnetic nanoparticles and macrophage.three kinds of magnetic nanoparticles have been involved in this study,i.e.flower like magnetic nanoparticles core-shell gold magnetic nanoparticles and Fe₃O₄nanoparticle The biological safety and biological effects of these nanoparticles on mouse macrophages?RAW 264.7?were investigated,including cell activity,cell phagocytosis,immune responses and magnetic nanoparticle adsorption proteins.The experimental results indicate that core-shell gold magnets and Fe₃O₄magnetic nanoparticles were not toxic at the experimental concentration,however,for the flower like gold nanoparticle,a dose dependent cytotoxicity effect could be observed when the concentration is higher than 100?g/m L.However,the treatment of all three kinds of nanoparticles show no significant influence on the expression of Caspase-3,which indicate that all tested nanoparticles did not induce cell apoptosis.ROS detection shown that flower like gold magnetic nanoparticles stimulated RAW 264.7 cells to produce the most ROS,followed by core-shell gold magnets,and the least amount of ROS was found with Fe₃O₄magnetic nanoparticles treatment.The lipid peroxidation was not observed with cell exposed to all tested nanoparticle.The results of cell polarization investigation indicate that flower like gold magnetic nanoparticles intend to promote RAW 264.7 to M1 macrophage,while core-shell gold magnets and Fe₃O₄magnetic nanoparticles have no effect on the cell polarization of RAW 264.7.At least,the adsorption of serum proteins on the surfaces of the three magnetic nanoparticles were detected.The results shown that the type and amount of proteins adsorbed on the surface of the core-shell gold magnetic and Fe₃O₄magnetic nanoparticles were similar,Which is quite different compared with that on flower like gold magnetic nanoparticles.