Preparation Of Multi-functional Magnetic Nanomaterials And Their Application In Biomedical Field

Recently,there was significant increase in cancer patients with the change of environment and lifestyle.Current traditional cancer treatments,such as chemotherapy,surgery and radiation therapy,more or less have disadvantages.Meanwhile,the development of multifunctional nanocarriers and their applications in biomedical field have attracted the attention of researchers in recent years,which have promoted the development of“nano-biomedicine”field.Therefore,the design of multi-functional nanocarriers(including photothermal therapy,drug delivery,magnetic resonance imaging,fluorescence imaging,etc.)have rapidly become hot spot in the field of nano-biomedicine.In this paper,we have prepared a multifunctional drug carrier nanocarrier for cancer therapy based on the current research situation.The specific research contents are as follows:(1)In order to achieve the targeted synergistic therapeutic effect of photothermal therapy and chemotherapy,we have prepared a nanocarrier with mesoporous structure and integrated photothermal therapy,targeted transport,drug loading and magnetic resonance imaging.The details are as follows:We firstly fabricated magnetic mesoporous silica nanoparticles(Fe₃O₄@mSiO₂),on which folic acid(FA)was grafted as the targeting reagent,CuS nanocrystals were attached as the photothermal agent,and polyethylene glycol(PEG)was coupled to improve biocompatibility.The characterization results demonstrated that the fabricated Fe₃O₄@mSiO₂-FA-CuS-PEG nanocomposites not only showed strong magnetism and excellent MRI performance,but also had a high doxorubicin(DOX,an anticancer drug)loading capacity(22.1%).The loaded DOX can be sustainably released,which was apt to be controlled by p H adjustment and near infrared(NIR,915 nm,1.0 W/cm²)laser irradiation.The cell experiment showed that Fe₃O₄@mSiO₂-FA-CuS-PEG/DOX laser groups could achieve the magnetic resonance imaging(MRI)guided synergetic effect by HeLa cells combined with folate receptor.Therefore,the multi-functional Fe₃O₄@mSiO₂-FA-CuS-PEG/DOX nanocarriers have outstanding application in the field of cancer therapy.(2)In order to shorten the preparation cycle of nanocarriers,we successfully prepared a kind of biocompatible Fe₃O₄@CS nanospheres by a simple one-step method.Doxorubicin(DOX,an anticancer drug)and indocyanine green(ICG)can be co-loaded into Fe₃O₄@CS nanospheres(Fe₃O₄@CS-ICG/DOX nanocomposites)by virtue of mesoporous structure and electrostatic interaction of CS.The fabricated nanocomposites showed an excellent magnetic resonance imaging(MRI)and fluorescence imaging performance for in vivo tumor.Moreover,the chemotherapy and photothermal therapy can be driven simultaneously under the NIR laser irradiation.Tumor growth could be effectively inhibited by chemo-photothermal combinational therapy in vivo,achieving excellent synergistic therapeutic efficacy.That is,the proposed biocompatible Fe₃O₄@CS-ICG/DOX nanocomposites can be used as a kind of multifunctional nanoplatform for MRI and fluorescence imaging guided chemo-photothermal combination therapy of cancer.In summary,multifunctional nanocarriers were masterly assembled by magnetic materials(based Fe₃O₄,a good contrast agent)and photothermal reagents,combining magnetic resonance imaging,chemotherapy and photothermal therapy,which have very good application in the field of cancer treatment.