Fabrication And Performance Research Of PH-sensitive Magnetic Silica Nanomaterials

In recent years,more and more attentions have been paid to the biological targeted drug therapy in cancer treatment.The drugs are mainly delivered to the lesion locations by adopting the targeted transport capability of nanomaterials,this will improve the therapeutic effect of drugs and reduce the toxic effect on the human body.The study found that diseased tissue cells and normal tissue cells are sustained in different physiological environments,mainly reflecting in their different pH conditions of the physiological environment.Therefore,the drug release using pH response has gradually become a hot research issues.In this paper,magnetic silica with excellent bioaffinity was used as substrate materials to prepare solid and mesoporous pH-sensitive drug delivery carrier which has great dispersion and particle size uniformity,and the drug loading properties of these two systems were also studied and analyzed.The main contents of this paper were as follows:1.Fe₃O₄ magnetic nanoparticles with different functional groups were synthesized by hydrothermal method and co-precipitation method,respectively.The nanoparticles prepared by hydrothermal method exhibited great dispersion and hydrophilicity,and the nanoparticles prepared by co-precipitation method showed poor dispersion and great hydrophobicity.All the nanoparticles had suitable diameter and high magnetic responses.Fe₃O₄ magnetic nanoparticles with small particle size and great hydrophobicity were considered as a subsequent reaction magnetic core,everything considered.2.Fe₃O₄@SiO₂ magnetic nanoparticles were prepared by microemulsion method,then through the modification of silane coupling agent,and a series of organic reactions,the surface of nanocomposites were grafted with a large number of hydrazine bonds,which can be connected with DOX to form pH-sensitive hydrazine bonds.The magnetic nanoparticles prepared by this method with the size of about 100 nm have a good magnetic responsiveness and low cytotoxicity,and can be used as a suitable target drug carrier.3.Fe₃O₄@mSiO₂ magnetic mesoporous nanomaterials were prepared by microemulsion method,then AlOOH was coated on the surface of nanocomposites.Using ammonium nitrate as a precipitating agent,the pH-sensitive layered double hydroxides?LDH?were synthesized by in situ growth.The prepared drug loading system had a particle size of about 100 nm,and exhibited good magnetic responsiveness and low cytotoxicity,and can also be used as a suitable drug carrier.4.Doxorubicin was loaded in carriers via hydrazine bonds,and methotrexate was housed in the channels of mesoporous silica and the interlayer of LDH to form a pH-sensitive magnetic targeted drug delivery system by molecular motion and ion exchange interaction.The experimental results showed that the suitable amount of anti-cancer drugs were loaded in these two drug delivery systems,and the systems both showed excellent pH-sensitivity and magnetic targeting.In addition,the systems was to control and kill tumor cells and achieve the purpose of cancer treatment.