Functionalized Graphite Phase Carbonitride Nanosheets For Anticancer Research

Carbon nitride?C₃N₄?is a material composed of carbon and nitrogen elements.Graphite phase carbonitride?g-C₃N₄?is one kind of C₃N₄,which is a graphene-like two-dimensional material.Since it has excellent photoelectric properties and exhibits good photocatalytic activity under visible light irradiation,g-C₃N₄ is widely used in the field of catalysis.At the same time,g-C₃N₄ has good solubility in water,large specific surface area and low biotoxicity,so g-C₃N₄ is gradually applied in biological detection and biological carriers.The bulk g-C₃N₄ can be obtained by calcining the nitrogen-rich precursor,and then the nano-scale g-C₃N₄ can be obtained by means of ultrasonic mechanical peeling or ultrasonic assisted liquid phase stripping.g-C₃N₄ can adsorb a compound or a drug molecule by means of ?-? stacking,electrostatic action or the like.In addition,different atoms can be modified to g-C₃N₄ or different functional groups can be formed on the surface of g-C₃N₄ by different exfoliation means.After that,g-C₃N₄ can be covalently modified or improved to optimize the application of g-C₃N₄ in different fields.In this paper,different modified g-C₃N₄ were studied,and two nanocomposites,g-C₃N₄/RBD/F127 and Dox/g-C₃N₄-PEG,were prepared.We examined the effects of sonodynamic therapy of g-C₃N₄/RBD/F127 and Dox/g-C₃N₄-PEG,and evaluated the therapeutic effects of the materials in cells by different means.This thesis is divided into four chapters.In the first chapter,we introduced the structure,properties and preparation methods of g-C₃N₄.We summerized the catalytic and biological applications of g-C₃N₄.Then we gave an explanation of the sonodynamic therapy and sonosensitive agents.Finally,we expounded the ideas for our research.In the second chapter,the bulk g-C₃N₄ was obtained by high temperature calcination of melamine,and then the g-C₃N₄ nanosheet was obtained by ultrasonic stripping.Subsequently,we synthesized rose bengal derivative?RBD?by reference,modified RBD on g-C₃N₄ nanosheet by ?-? interaction,and wrapped F127 in the outermost layer.Finally g-C₃N₄/RBD/F127 was obtained.In the third chapter,we changed the stripping method that bulk g-C₃N₄ was mixed with nitric acid,refluxed,and then stripped under ultrasonic.After that,we obtained g-C₃N₄ with carboxyl groups.Doxorubicin?Dox?was loaded on the g-C₃N₄ nanosheets after the nanosheets were modified with PEG by formation of amide bond.After the solution experiment and cell experiment,we evaluated the sonodynamic ability of Dox/g-C₃N₄-PEG and the synergistic effect of sonodynamic therapy and chemotherapy.We verified that Dox/g-C₃N₄-PEG has excellent effct of killing tumor cells.In the last chapter,we summarized the experimental data.We discussed the prospects for the development of g-C₃N₄/RBD/F127 and Dox/g-C₃N₄-PEG nanocomposites,as well as the problems and shortcomings.