Chemical Synthesis Of A Novel Carbon-based Nanomaterials And The Application In Tumor Diagnosis And Treatment

Tumor is one of the most serious diseases threatening human health.Early diagnosis and treatment of tumor is the key to improving the quality of life and cure rate for patients.Traditional imaging methods such as X-ray,CT,MRI,and PET are difficult to locate and characterize tumors in the early stage,and the existing clinical treatment methods such as radiotherapy and chemotherapy have relatively large side effects,which greatly limits the accuracy of tumor diagnosis and treatment.With the rapid development of nanotechnology,multifunctional nanomaterials have received widespread attention.Compared with traditional diagnosis and treatment,multifunctional nanomaterials have unique physical and chemical properties and physiological ability,which can maximize the targeted delivery of drugs and realize the synergistic effect of diagnosis and treatment.The introduction of nanomaterials provides a new functional technology for the early diagnosis and treatment of cancer and other major diseases.Among them,carbon-based nanomaterials can be used in the field of biomedicine due to their unique physical and chemical properties.As a novel drug delivery system and photosensitizer,they have won more and more attention.At the same time,because the synthesis process of carbon-based materials is economical and cost-effective,the possibility of clinical transformation and large-scale industrial production is far greater than that of traditional nanomaterials.Although carbon-based nanomaterials have been widely used,there are still some urgent problems to be solved.Most of the carbon-based nanomaterials can absorb the light of the near-infrared window(NIR-?),and has poor tissue penetration,which limits the diagnosis and treatment results of tumors.In addition,most of the existing carbon-based nanomaterials only undergo a single photothermal therapy(PTT),and the therapeutic effect is not ideal.Therefore,the application of carbon-based materials in tumor diagnosis and treatment needs further research and discussion.In this thesis,mesoporous Beta molecular sieves were used as templates to synthesize a novel silicon carbon nanomaterials(HSC)and hollow carbon materials(HC)through the template-carbonization-corrosion process,and used their unique physical and chemical properties to obtain the hollow carbon-based nanomaterials(HC-AB)by loading Ammonia Borane(AB),a hydrogen storage material,which are used in tumor diagnosis and treatment.The main research contents and research conclusions are listed as follows:(1)Using tetraethylammonium hydroxide(TEAOH)as the template,sodium metaaluminate(Na Al O₂)as the aluminum source,and white carbon black as the silicon source,Beta molecular sieve was synthesized by one-step hydrothermal method,and then used as the template to coated with ionic liquid 1-butyl-3-methylimidazole bromide(BMIMBr),a composite material(Beta-C)was obtained by high-temperature carbonization,and a novel silicon carbon nanomaterial HSC was obtained by etching Beta molecular sieve with sodium hydroxide(Na OH).The effect of different feed ratios(the mass ratio of Beta molecular sieve to ionic liquid)on the performance of the synthesized Beta-C in near-infrared two-area fluorescence imaging(NIR-? FI)was explored.The experimental results show that the NIR-? FI of Beta-C is the strongest when m _Beta:m _BMIMBr=1:6.Then XRD,TEM,XPS,FT-IR,UV-Vis,DLS and other characterization methods are used to characterize the physical and chemical properties of HSC,such as morphology and structure;at the same time,various imaging systems were used to evaluate the diagnostic and therapeutic performance of HSC at the in vitro,cellular and in vivo levels.The results show that the particle size of HSC is about200 nm,and the morphology is quasi-spherical.The nanomaterial has ultraviolet absorption in both the near-infrared one-region window(NIR-?)or the near-infrared two-region window(NIR-?),it also has the imaging performance of NIR-? FI and NIR-? photoacoustic(NIR-? PA).In addition,the nanomaterial can quickly generate heat and has good stability under 1064nm laser irradiation,showing excellent NIR-? photothermal performance;cell experiments have also shown the low toxicity of HSC;finally,HSC was injected into tumor-bearing mice through the tail vein to explore the effect of the nanomaterial in tumor diagnosis and treatment.It can be seen from the imaging of NIR-? FI and NIR-? PA that HSC accumulate the most at the tumor site of mice after 12 h of injection.By monitoring the state of the mice,it is not difficult to find that the tumors of the mice were disappeared after 10 d of NIR-? photothermal therapy(NIR-? PTT).(2)The Beta molecular sieve was used as a template to coat the ionic liquid on it,and the Beta-C composite was obtained by high-temperature carbonization.The Beta molecular sieve was completely etched using Na OH to obtain the hollow mesoporous carbon nanomaterial(HC)and AB was loaded on the HC to obtain hollow carbon-based nanomaterials(HC-AB).The effect of different AB content on the hydrogen production performance of HC-AB is explored.The results show that the hydrogen production performance of HC-AB is the most suitable when m _HC:m _AB=1:5,the nanomaterials at this time are referred to as HC-AB.Then TEM,UV-Vis,DLS,BET and other characterization methods were used to characterize the physicochemical properties of HC-AB such as morphology,structure and pores,at the same time,the diagnostic and therapeutic properties of HC-AB nanomaterials were evaluated at the in vitro,cellular and in vivo levels.The results show that the particle size of HC-AB is about 200 nm,with a hollow-like spherical structure,with NIR-? PA imaging and excellent NIR-? photothermal performance.Under 1064 nm laser irradiation,on the one hand,HC-AB can be rapidly heat up,on the other hand,the heat generated in the NIR-? PTT also can accelerate the production of H₂.Finally,HC-AB were injected into tumor-bearing mice through the tail vein to explore the effect of nanomaterials in tumor diagnosis and treatment.It can be seen from NIR-? PA imaging that HC-AB accumulate the largest amount at the tumor site of the mouse 6 h after injection,and by monitoring the state of the mouse after treatment,the tumor of the mouse was disappeared completely after 10 d.