Application Research Of N-Ti₃C₂ Quantum Dots And Bowl-shaped Polydopamine Nanomaterials In Cancer Diagnosis And Treatment

Biomedical nanomaterials are developing towards the direction of functionalization and intelligence.It is a new trend of nanoscience&technology development in recent years to build technology platforms for disease diagnosis and treatment by using the functionalization and intelligence of nano materials.Based on this,we designed and synthesized low toxic N-doped Ti₃C₂ MXene quantum dot?N-Ti₃C₂ QDs?and bowl shaped polydopamine?b-PDA?nanoparticles,which were used in the preparation of glutathione fluorescence sensor and photothermal/chemical drugs combination therapy for the diagnosis and treatment of tumor.The details are as follows.1.Construction of fluorescence probe N-Ti₃C₂ QDs/Fe³⁺for detection of glutathione?GSH?.First,N-Ti₃C₂ QDs were synthesized by hydrothermal method,and N-Ti₃C₂ QDs/Fe³⁺biosensor was prepared based on their specific response to Fe³⁺,which Fe³⁺can quench the fluorescence of N-Ti₃C₂ QDs and the reduction of GSH,which can reduce Fe³⁺to Fe²⁺,making N-Ti₃C₂ QDs fluorescence recovery).Then a new fluorescence sensor was constructed to detect GSH overexpression in tumor cells with a detection limit of 0.17?M.Final,the potential application of the quantum dots in biological cell imaging was also verified.2.Preparation and properties of bowl shaped polydopamine?b-PDA?photothermal therapeutic nanoagent.First,b-PDA nanoparticles were prepared and characterized,and then their biocompatibility and water dispersion were improved by the modification of m PEG-NH₂.In addition,the photothermal effect of b-PDA solution was also studied.The experimental results showed that it had a strong absorption in the near infrared?NIR?region.Under NIR irradiation?808 nm?,the aqueous solution of m PEG-b-PDA nanoparticles showed a rapid warming effect and the photothermal conversion efficiency of m PEG-b-PDA nanoparticles was 32%.Based on this,the prepared b-PDA nanoparticles can be used as photothermal nanoagents for breast cancer cells?MCF-7?treatment,and the experimental results also proved that they showed good photothermal treatment effect and can kill tumor cells in vitro.3.Preparation and properties of m PEG-b-PDA/DOX as therapeutic agent for photothermal/chemical drugs combination therapy.Based on the large specific surface area of b-PDA and the anticancer drug DOX loaded by physical adsorption,the m PEG-b-PDA/DOX multifunctional nanomaterials were designed and synthesized.The experimental results showed that under the stimulation of p H and near-infrared light,DOX can be released in a controlled way,and at the same time,the combination effects of photothermal and chemical drugs can be achieved,so as to provide a theoretical basis for the realization of multi-functional cooperative therapy.