Synthesis Of Multifuctional Metal Graphitic Nanocapsules And Its Application In Disease Diagnosis And Treatment

Because of the rising researches about diseases,the traditional diagnosis and treatment system gradually cannot meet the various needs of doctors and patients.Therefore,it is significant to develop a new system.Nanomaterials,with high activity,high specific surface area,ultra-small size and easy modification,have become an important tool for the novel diagnosis and treatment systems.For example,the traditional tumor treatments hardly eradicate tumor and have medical adverse effects,which shows negative impacts on normal body organs and tissues.In order to solve the problems,nanomaterials are regulated the size,morphology and modified with functional targeted molecules,to achieve active targeting,multi-modal imaging and controlled drug release.However,there are still many difficulties and challenges in the application of nanomaterials for disease diagnosis and treatment.The human physiological environment is complex,and nanomaterials will face a variety of effects on the biological small molecules,cells and organs.This phenomenon may result in the off-target and dysfunctional nanomaterials,which reduced the therapeutic efficiency.Meanwhile,the large accumulation of nanomaterials in metabolic organs also raises concerns about their biocompatibility.Therefore,a variety of metal graphitic nanocapsules are synthesized through chemical vapor deposition（Chemical Vapor Deposition,CVD）in this paper to solve the problems of selectivity,safety and low therapeutic efficiency of nanomaterials in the existing system.The specific contents are as follows:（1）In Chapter 2,we prepared gold nanorod graphitic nanocapsules（Au NR@G）and explored its application in cell diagnosis and treatment system.First,Au NRs prepared by the seed-mediated growth method,and then we synthesized Au NR@Si O₂to protect the rodlike morphology for further Au NR@G nanocapsules synthesized by CVD method,and then we characterized the structure of Au NR@G nanocapsules using variety of analytical instruments.We studied the NIR photothermal effects and multi-model images of Au NR@G for the future development in vivo.（2）In Chapter 3,we synthesized aspirin prodrug functional Au NR@G（Au NR@G-Pyrene-aspirin,Au NR@G-P-aspirin）and further explored its treatment application in vivo.We prepared the prodrug（Pyrene-aspirin,P-aspirin）,which can be loaded at Au NR@G,to controlled release aspirin in the tumor microenvironment and eliminate inflammation.Subsequently,the photothermal therapy（PTT）experiment showed that Au NR@G has a excellent photothermal effect.However,the mechanism of cell necrosis in PTT may induce the typical accompanying pro-inflammatory,which may induce tumor growth.Subsequently,the cytokines levels experiment investigated that Au NR@G-P-aspirin could effectively anti-inflammation,which showed better tumor inhibition in vivo.In summary,we designed a safe therapeutic strategy for the further development in future.（3）In Chapter 4,we prepared platinum graphitic nanocapsules（Pt@G）and studied its application in vitro.Pt@G demonstrated that it has good photothermal properties,catalytic properties and Raman imaging properties.Compared with uncoated Pt,Pt@G has better safety in normal cells.Because of the unique structure,we found that Pt@G had a significant selectively killing of fibrosarcoma cells（HT1080）through regulating the metix metalloproteinase（MMP）expression and cellular redox status.This result provides the possibility to improve the cell selectivity of nanomaterials.（4）In the last chapter,we designed the magnetic platinum graphitic nanocapsules（Co Pt@G）,which functionalized by glucose oxidase（GOx）,and studied their application for preventing biofilm-induced oral disease.Co Pt@G@GOx uses a cascade reaction to catalyze glucose to produce gluconic acid and hydroxyl radical（·OH）to kill caries-induced harmful bacteria in oral biofilms.At the same time,Co metal with magneto-actuated effect could improve the site-fixing ability for Co Pt@G@GOx treatment,which improved the treatment efficiency without affecting the normal tissue during the treatment.The Co Pt@G@GOx platform solves the problems of the biofilms matrix and the acid condition induced low drug delivery efficiency and poor current nanoparticle-mediate therapeutic effectiveness.In summary,Co Pt@G@GOx can be a novel agent to prevent biofilm-induced disease.