Preparation And Biomedical Application Of Multifunctional Nanomaterials By

Nanomaterials have exhibit excellent physicochemical properties due to their high surface area and nanoscale size and have great potential for applications in the biomedical fields,such as imaging,drug loading,anti-tumor,antibacterial,regeneration and so on.For example,ferromagnetic and paramagnetic nanoparticles are used for nuclear magnetic resonance imaging;nanomaterials with high X-ray absorption coefficient elements such as bismuth,gold and zirconium are used for CT imaging;quantum dots and upconversion nanomaterials are used for fluorescence imaging;mesoporous or hollow structures nanomaterials are used for drug loading;photothermal materials are used for photothermal therapy and photoacoustic imaging;silver-containing nanomaterials are used for antibacterial treatment.With the development of nanotechnology,inexpensive,gentle and simple preparation and assembly methods provide greater feasibility for obtaining reasonable multifunctional nanomaterials for biomedical applications.As multifunctional nanomaterials are used as more comprehensive and effective nanoplatforms,shows better application prospects.This article will comprehensively expound the biomedical application,synthesis,characterization and development direction of multifunctional nanomaterials.Mainly include the following works:1)The core-shell structure of SiO2-coated quantum dot(QD)is synthesized by the reverse microemulsion method.The controllable thickness of QD/SiO2 core-shell structure of single-core particles is obtained by adding different amounts of ethanol,thereby avoiding a large amount presence of quantum dots in nanocomposites due to quantum dots has greater biological toxicity.Next,ZrO2 is coated on the surface of SiO2 by hydrolysis of zirconium n-propoxide.Based on the high X-ray attenuation coefficient of the Zr element,it can be used for CT imaging.Then,the folic acid(FA)was modified on the surface of QD/SiO2/ZrO2 to increase the uptake of nanocomposites by tumor cells.Finally,we synthesized and characterized of QDs/SiO2/ZrO2-FA nanocomposites.The nanomaterials exhibit excellent compatibility with hepatocytes and hepatoma cells by cytotoxicity tests in vitro.In addition,in vitro fluorescence imaging showed FA-modified nanocomposites significantly increase the intake of hepatoma cells.2)Bi2S3 nanomaterials with adjustable aspect ratio were prepared by hydrothermal reaction of bovine serum albumin(BSA)and bismuth nitrate pentahydrate mixed solution.By adjusting the concentration of BSA in the reaction system,irregular nanosheets and popsicle-like nanorod structures can be obtained,and it is clearly observed that the aspect ratio changes during the change of the BSA concentration.Then,we evaluated the photothermal conversion properties,photoacoustic and CT imaging effects of Bi2S3 nanomaterials in aqueous solution.Moreover,we demonstrated the excellent biocompatibility of the Bi2S3 nanomaterials by cytotoxicity analysis in vitro.Finally,the excellent photothermal effects were further confirmed by photothermal therapy in vitro.3)We synthesis of poly dopamine-doped mesoporous silica coated reduced graphene oxide nanosheets(rGO/MSN/PDA)and loaded with doxorubicin(DOX)for chemotherapy and photothermal synergistic therapy.rGO/MSN/PDA was obtained by additional adding dopamine hydrochloride in the synthesis of GO/MSN.The operation is simple,but the performance of nanocomposites is significantly improved.The photothermal conversion performance test confirmed the obtained PDA and the reduction of graphene oxide during the synthesis process have improved the photothermal performance of the nanocomposites.Simultaneously,the nanomaterials exhibited better biocompatibility through in vitro cytotoxicity tests.In addition,the therapeutic effect remarkable improved through chemotherapy and photothermal synergy therapy in vitro.4)We synthesis silver nanoparticle-modified mesoporous silica coated reduced graphene oxide nanosheets(rGO/MSN/Ag)for photothermal synergistic antimicrobial treatment.Nanocomposites with antibacterial and photothermal conversion properties were constructed by loading small silver nanoparticles with controllable size on mesoporous silica-coated reduced graphene oxide.The excellent antibacterial properties of Escherichia coli(E.Coli),Pseudomonas putida(P.Putida)and Rhodococuss were demonstrated by minimum inhibitory concentration tests.However,the decrease of antibacterial properties with the increase of the bacterial population indicates that the high concentration of bacteria exhibited insensitivity to the nanocomposites.However,through photothermal treatment,a significant antibacterial enhancement based on photothermal synergy was demonstrated.