Study On Magnetic Iron Oxide Nanoparticles In Stem Cell Differentiation And Biofilm Eradication

Magnetic iron oxide nanoparticles have controllable particle size,good biocompatibility,stable physicochemical properties and good sensitivity to magnetic fields,which makes them to be one of the most promising biomaterials for biomedical applications.Their high surface-area-to-volume ratio is the basis for their subsequent modification by biological functional molecules.These modified magnetic iron oxide nanoparticles can be widely used in magnetic separation,magnetic transfection,targeted transportation,bio-imaging and cancer treatment.Therefore,in this paper,magnetic iron oxide nanoparticles with special properties were used to explore roles of magnetic iron oxide nanoparticles in neural differentiation of stem cells and biofilm elimination by studying their interaction with bacteria and cells.The specific research contents are as follows:(1)The effects of magnetic iron oxide nanoparticles on neural differentiation of mouse embryonic stem cells under magnetic fields.Firstly,thermal decomposition method was used to synthesize magnetic iron oxide nanoparticles(MIONs)with size of around 20 nm,which could disperse well in organic phase.Then,these nanoparticles were subjected to a phase inversion experiment with a small molecule 3,4-dihydroxyhydrocinnamic(DHCA),resulting in dispersing in aqueous phase.Because of the small size,MIONs could easily enter cells through endocytosis of cells after co-cultured with them.Then,neural differentiation of mouse embryonic stem cells was studied after cultured for 7 and 14 days respectively under a magnetic field.The results of experiments showed that no significant change occurred in neural differentiation of embryonic stem cells when magnetic iron oxide nanoparticles or magnetic fields were used alone.However,the interaction between MIONs and the magnetic fields significantly promoted the differentiation of the embryonic stem cells into nerve cells,and the promoting effect did not depend on the neural differentiation medium.Most importantly,with the combination of MIONs,magnetic fields and neural differentiation medium,neural differentiation of embryonic stem cells was significantly promoted,and the expression levels of mature neural cells marker genes increased by 60 times.The results indicated that the synergistic effect of magnetic iron oxide nanoparticles,magnetic fields and neural differentiation medium could significantly promote the neural differentiation of embryonic stem cells.(2)The effects of porous magnetic iron oxide nanoparticles loaded with an inhibitor of heat shock protein on biofilm elimination.Porous magnetic iron oxide nanoparticles(P-MIONs)were used to encapsulate an inhibitor of heat shock protein(2-phenylethynesulfonamide,PES),abbreviating to P-MIONs-PES,and entered the interior of the biofilms under a magnetic field.After exposure to near-infrared light,the activities of bacteria in biofilms were tested.The results of experiments showed that the temperature of the whole system was increased for the photothermal effect of P-MIONs,and the heat resistance of bacteria was reduced due to the inhibition of heat shock protein on the surface of bacteria by PES.Therefore,compared to P-MIONs,P-MIONs-PES had a better eradication effect on bacteria in biofilms.The method using high load capacity and photothermal effects of the porous structure of P-MIONs can be well used in the elimination of biofilms.In summary,in this paper,the neural differentiation of embryonic stem cells was significantly promoted through the synergistic effects of magnetic iron oxide nanoparticles,magnetic fields and neural differentiation medium.The biofilms were effectively eliminated using porous magnetic iron oxide nanoparticles-loaded inhibitors of the heat shock protein in combination with a photothermal effect.The results of this study have great potential in the treatment of neurodegenerative diseases and the elimination of biofilms.