Preparation And Characterization Of Fe₃O₄@Dextran Nanoparticles And Their Photothermal And Antitumor Effects

Research BackgroundMalignant tumor is the greatest threat to human health today.According to the data published by World Healt h Organization in 2017,it showed that the global annual 8.8 million people died of ma lignant tumors,accounting for the world's total annual death rate of 1/6.Tradit ional treatments such as chemotherapy,radiotherapy and surgery,although there is a certain therapeutic effect,but its huge toxic effect is to limit its further play.Photothermal therapy as a new method of tumor treatment has attracted widespread attention of tumor therapy researchers.Photothermal therapy uses nanomaterials with photothermal effects as photothermal agents and near infrared light with a strong tissue penetration as a light source.Nanomaterials generate heat at the tumor site under laser irradiation to achieve tumor eliminat ion.In recent years,superparamagnetic iron oxide nanoparticles?SPIO s?have been found to have good photothermal conversion properties.As a functional material,SPIOs have shown great potentia l in biomedical applications,includ ing various biological separation technologies,drug targeting vectors,magnetic resonance imaging?MRI?and tumor hyperthermia.The US Food and Drug Administration?FDA?has approved Fe₃O₄ nanoparticles as contrast agents for MIR,demonstrating long-term biosafety of Fe₃O₄ nanoparticles.Due to the poor dispersib ility and stability of Fe₃O₄ nanopartic les in solut ion,the surface modification of Fe₃O₄ nano-particles to enhance their dispersion and stability in solut ion,and their application in photothermal therapy has great research potential.PurposeIn this study,the Fe₃O₄@dextran nanoparticle was applied to the photothermal therapy from the aspects of preparation and characterization of Fe₃O₄@dextran nanoparticle,investigat ion of phototherma l properties,biosafety evaluation and anti-tumor effect.Provide basic research for the application of Fe₃O₄@dextran nanoparticle as a photothermal therapeutic agent.MethodsFe₃O₄@dextran nanoparticles were synthesized by co-precipitation method.The optimal synthesis process was screened by examining the ratio of the reactants,the stirring rate and the reaction temperature;the prepared nanoparticles were characterized,their morphology and partic le size were analyzed by transmission electron microscopy and scanning electron microscopy,and they were analyzed.At the same time,the magnetic properties,spectral absorption,therma l weight,ele mental composition and dispersion stability of nanoparticles were analyzed.The photothermal conversion properties of Fe₃O₄@dextran nanoparticle in the solid state and solut ion dispersion state were investigated through a self-made experimenta l device.The material,nanoparticle concentration,laser wavelengt h and laser power were investigated.The cytotoxicity and photo-thermal toxicity of Fe₃O₄@dextran nanoparticles were studied by MTT assay.The in vivo safety of Fe₃O₄@dextran nanoparticles was further studied in tail vein injections.Routine,blood biochemical and tissue sections are safety evaluation indicators.Fina lly,photothermal ant i-tumor effects of Fe₃O₄@dextran nanopartic les were studied by in vitro cell exper iments and in vivo experiments.Results and conclus ionsThe optimum preparation conditions of Fe₃O₄@dextran nanoparticles were as follows:the mass ratio of dextran,FeC l₃·6H₂O and FeC l₂·4H₂O was 40:3:1,the optimum reaction p H was 10 and the optima l react ion temperature was 60°C.;The results showed that the average particle size of the prepared Fe₃O₄@dextran nanoparticles was 98.7±11.6 nm.Nanoparticles have clear morphology,uniform partic le size distribution,and have superparamagnetis m.They absorb in the near-infrared region and have better dispersion and stability than Fe₃O₄nanoparticles without glucan coating.The phototherma l properties of Fe₃O₄@dextran nanoparticles showed that nanoparticle concentration and laser power were the key factors affecting the temperature increase of nanoparticles.The higher nanoparticle concentration and the laser power and the higher temperature is.The biosafety evaluat ion results of Fe₃O₄@dextran nanoparticles showed that the concentration of Fe₃O₄@dextran nanoparticles at the concentration of 1 mg/m L showed no difference compared with the control group.In vivo experiments also showed that Fe₃O₄@dextran nanopartic les did not cause changes in the hematology and tissue physiology of mice.The prepared Fe₃O₄@dextran nanoparticles ha d high biosafety.The in vitro and in vivo photothermal anti-tumor experiments of Fe₃O₄@dextran nanoparticles showed that tumor cells and tissues c ould be eliminated when both Fe₃O₄@dextran nanoparticles and near-infrared laser irradiation were present.The results show that the prepared Fe₃O₄@dextran nanoparticle has good stability and high biosafety,and there is a strong phototherma l anti-tumor effect that can be used as a photothermal therapeutic material.