Application Of Multifunctional Ti₃C₂@Au Nanocomposites In Tumor Diagnosis And Treatment

Today,cancer?malignant tumors?is one of the great threats to human health and life.With the rapid development of nanotechnology,molecular imaging,and tumor biology,nanomedicine has shown good results in the process of cancer conquest.More and more experts and scholars believe that nanomedicine will plays a pivotal role in the fight against disease.In recent years,with the rapid development of nanotechnology,nanomaterials have attracted extensive attention from biomedical researchers.Due to their unique physical and chemical properties such as light,electricity and magnetism,nanomaterials are playing an increasingly important role in tumor diagnosis and treatment,such as drug delivery,biological imaging,optical therapy,radiotherapy and so on.In addition,nanomaterials can be effectively enriched in tumor through active or passive targeting,so as to further improve the therapeutic effect while reducing toxic and side effects.Therefore,multifunctional nanomaterials can achieve efficient combination of multiple imaging and treatment methods.At present,Multifunctional nanoplatforms with special advantages in the diagnosis and treatment of cancer have been widely explored in nanomedicine.The visualization,individualization and precision of the cancer treatment process has become an important development direction in the field of nanomedicine,and these strategies will effectively reduce the side effects of treatment and ultimately achieve high treatment efficiency for tumors.Two-dimensional transition metal carbon/nitrogen compounds?MXenes?is a new two-dimensional layered material.Its unique properties have made it widely studied in recent years.As one of the earliest MXenes materials,Ti₃C₂ has great potential in electrochemistry,sensing,nanomedicine and other fields with its good hydrophilicity and optical properties.In this thesis,we synthesized two-dimensional transition metal carbide materials?Ti₃C₂?and construct multifunctional nanomaterials-Ti₃C₂@Au,then the obtained Ti₃C₂@Au were applied in the diagnosis of tumors.The main research contents are as follows:1.In chapter 2,we established a multifunctional nanomaterial Ti₃C₂@Au and explored its capabilities in photothermal transformation,photoacoustic?PA?imaging and computed tomography?CT?imaging.In this section,we firstly used low concentration of hydrofluoric acid?HF?and tetrapropylammonium hydroxide?TPAOH?to selectively etching Ti₃AlC₂ crystal layer,eventually obtained the ultrathin Ti₃C₂ nanosheets.Then,polypropylene amine hydrochloride?PAH?and negatively charged gold nanoparticles were separately absorbed on Ti₃C₂ surface through electrostatic interaction.Finally,multifunctional nanomaterial Ti₃C₂@Au were obtained by seed growth method.After surface modification with Thiol Polyethylene Glycol?SH-PEG?,the biological stability of Ti₃C₂@Au greatly improved.Due to the plasmon resonance effect between Ti₃C₂ and gold shell,the optical properties of Ti₃C₂@Au were better than Ti₃C₂,Ti₃C₂@Au have a stronger photothermal conversion properties and absorption in the near infrared region.In addition,the gold shell of Ti₃C₂@Au endows Ti₃C₂@Au with high X-ray attenuation ability,which is convenient for CT imaging.In summary,Ti₃C₂@Au not only has good photothermal conversion ability,but also has excellent PA imaging and CT imaging ability.2.In the third chapter,we carried out in vitro and in vivo application research based on multifunctional nanomaterial Ti₃C₂@Au-PEG.First,we conducted cytotoxicity assessment,DNA damage,cell clonogenic assay,cell therapy and other experiments with Ti₃C₂@Au-PEG in vitro.We found that Ti₃C₂@Au-PEG showed a good cytotoxic ability under the induction of near-infrared laser or X-ray.Moreover,Ti₃C₂@Au-PEG induced by near infrared light produces can produce mild photothermal effect in vivo,which can improve the oxygen content in the tumor area and enhancing the effect of Radiotherapy?RT?.Due to the excellent photothermal conversion ability and high X-ray attenuation ability of Ti₃C₂@Au-PEG,we achieved PA/CT dual-modal imaging guided tumor treatment with high efficiency.