Preparation And Characterization Of Gold Nanocomposite And Study On Antitumor And Antibacterial Activity

Nanomedicine has been used more and more widely in the treatment of tumors and antibiotics.Among them,Nanogold has attracted the most attention in biomedicine because of their advantages of uniform size,adjustable particle size and low cytotoxicity.Based on these advantages,such materials can also be used in combination with other tumor treatment technologies,such as photothermal therapy,photodynamic therapy,photoacoustic therapy,etc,resulting in enhanced the therapeutic effect of tumor.At present,the reported metal nanomaterials for tumor therapy have a single therapeutic function,which limit the therapeutic effect.Therefore,the development of natural drug composite metal nanomaterials for the treatment of cancer and antibacterial,is a focus in biomedical researchIn this thesis,we reviewed multi-function gold nanomaterials and their applications in tumor imaging,treatment and antibacterial applications.Design and synthesis of the three different types of natural products gold nanoparticle composites were studied.The nanoparticles were characterized using UV,IR,TEM and SEM method.Moreover,solar-thermal conversion performance,in vitro cell imaging and drug release properties of the nano composites were studied.The main novelties are shown as follows:?1?Using a natural product coffeine as raw material,a new type of fluorescent nano-caffeine gold composite was synthesized by one-step hydrothermal method,the structure of nano-caffeine gold was characterized and its optical properties were studied.It was found that nano-caffeine gold had good fluorescence properties and longer fluorescence lifetime.In addition,it can be used as fluorescent sensor for the detection of curcumin very sensitively.Compared with reported methods for detecting curcumin,its measurable concentration range is wider.Further research results on the nano-caffeine gold cytotoxicity and cell imaging revealed that it can enter tumor cells and sense curcumin in tumor cells,which is the first report.Therefore,the nano-caffeine gold is a fluorescent probe capable of detecting curcumin and an intelligent drug deliver.?2?In order to explore the multi-effect treatment of new nanomaterials for hypoxic tumors,the gold-manganese nanocomposite?DNAG-L₂Mn@Caffeine-Au?was synthesized,the structure of the nanocomposite was characterized.It was found to have good fluorescence properties,low cytotoxicity and excellent biocompatibility.Through cell imaging experiments and comparison of bright and dark fields,it was found that DNAG-L₂Mn@Caffeine-Au nanocomposite can enter living MCF-7 cells and can be used as a probe for cell imaging.Further biological assay results indicate that the GLUT-4 nucleic acid conjugated the nanocomposite can target tumor cells and interfere with HIF-1 expression.Therefore,DNAG-L₂Mn@Caffeine-Au can be used as a potential nano-antitumor drug.?3?A metal nanomaterial composed of MOF material ZIF-8 and gold nanorods was synthesized and loaded with the natural drug asiatic acid to form a ZIF-8@AuNRs-AA nanocomposite.Various methods were used to characterize the structure of the nanocomposite,and its stability and photothermal properties were studied.It was found to have good photothermal properties,excellent stability and excellent drug loading capacity.Cell experiment results indicate that the nanocomposite has low toxicity.Antibacterial experiments demonstrate that it has a good antibacterial property.Therefore,ZIF-8@AuNRs-AA can be used as a multi-effect low toxicity nano-antibacterial material.