Gold Nanoflowers-based Multifunctional Nano-platform For Diagnosis And Treatment Of Tumor Cell

Accurate diagnosis of cancer cell and the following effective drug therapy with high drug delivery efficiency,low toxicity and side effects can significantly improve the curative effect.Recently,the development of novel nanosystem integrating efficient tumor diagnosis and treatment has become an urgent demand.Aiming at this requirement,a traceable and targeted gold nanoflowers-based nanosystem with high drug encapsulation and p H-controlled release was studied and prepared for efficient targeted-SERS imaging and intracellular imaging-guided chemo-phototherapy.The specific research content of this thesis is as follows:In the first part,a kind of flower-like gold nanoparticles(Au NFs)with large surface area,moderate size,NIR-surface plasmon resonance feature and good SERS activity was synthesized.The influence of the ratio of materials and reaction temperature on the nanoparticle morphology and their special optical properties were studied and the controllable preparation method was proposed.The Au NFs show good morphological,optical,SERS and photothermal properties.In the second part,bright SERS probes which can target lung cancer A549 cells were prepared based on the Au NFs.Firstly,the Raman molecules were assembled on the surface of Au NFs,and then the polypeptide molecules(RGD)were coupled with the Raman molecules to construct SERS probes.The SERS response of the SERS probes and their targeted-SERS imaging of cancer cell,as well as their stability were studied and characterized.In the third part,the Au NF-based multifunctional nanosystem integrating with the function of cancer cell diagnosis and treatment was proposed and prepared.Firstly,the surface of the above-mentioned SERS probers was modified by PAA-SH to improve the efficiency of drug(DOX)loading and possess a p H-responded drug release property.Then the curative effect of SERS image-guided photothermal-chemotherapy therapy was studied.The experimental results indicate that the proposed Au NF-based multifunctional nanosystem shows good performance on targeted-SERS imaging,high-efficiency drug loading,p H-controlled drug release and improved photothermal-chemotherapy therapy,which is except to achieve effective diagnosis and treatment of cancer cells.