Peptide-Regulated Synthesis Of Zeolitic Imidazolate Framework-8 (ZIF-8) And Their Applications

With the rapid development of nanotechnology in recent decades,functional nanomaterials have attracted extensive research attention.Scientists are committed to developing nanomaterials with superior performance,safety and stability to meet the needs of different fields.At present,there have been a large number of research reports on high performance nanomaterials based on porous silicon,metal nanoparticles,graphene oxide,hydrogels,peptide self-assembly,and metal organic framework materials（MOFs）.Among them,MOFs,as a new variety of porous solid materials,is a type of nanomaterials that has developed rapidly in recent decades.This porous material has been deeply researched for its excellent characteristics such as large surface area,high porosity and easy functionalization.Considering these advantages,MOFs are widely used in many fields due to their application prospects,for instance,gas storage and separation,catalysis,sensors,and drug carriers.In this article,the zeolite-imidazole framework material（ZIF-8）was select to construct a drug carrier system as main research material for its superiority characteristic.Rely on this system,we synthesize an integrated diagnosis and treatment agent that can effectively treat cancer.The main research contents are as follows:1.As a type of coordinated porous nanomaterials,the adsorption and containment performance of MOFs will be improved by regulating the size and morphology of crystals to obtain a higher surface area and pore volume.In this thesis,we systematically adjusted the shape and size of ZIF-8 crystals by peptides as the regulator,and the performance of ZIF-8crystals after regulation is researched in depth as well as modulation mechanism.In related study,surfactants can effectively control the morphology and size of MOFs as a modulator.The amphiphilic peptide molecules as a similar modulator,the hydrophobic fragments can effectively regulate the shape and particle size of ZIF-8 crystals.Furthermore,peptides are more suitable for drug delivery due to high capacity and rich functions.Therefore,ZIF-8crystals with uniform sizes and different shapes can be synthesized in an aqueous solution by adding peptides into a one-pot process.At a peptide concentration of 1.0 m M,the morphology of ZIF-8 crystals was cubic,truncated rhombic dodecahedron,and typical rhombic dodecahedron in the cases of I₂R₄,I₄R₄,and I₆R₄,respectively.Also,the particle size can be regulated from ca.1.7μm to<100 nm by controlling the peptide concentration from 0 to 2.0m M.2.In recent years,the integration of diagnosis and treatment is a hot research topic in the treatment of cancer,and this excellent treatment brings new hope for human to overcome cancer.The construction of functional nanomaterial is core to integrate diagnosis and treatment in theranostic.In this paper,ZIF-8 is studied and used as a carrier for constructing a diagnosis and treatment nano-platform,and through the surface functionalization:synthesizing manganese dioxide on the surface of ZIF-8 crystals.As a result,this functional nanoparticle with multiple functions of improving the cell microenvironment and diagnosis through NMR that can treat cancer by loading Doxorubicin hydrochloride（DOX）for Chemotherapy and Chlorin e6（Ce6）for Photodynamic therapy（PDT）.The morphology,particle size and properties of the material were characterized by various characterization instruments such as TEM,SEM,XRD,DLS,FTIR,XPS,and the drug release performance and cytotoxicity of the integrated diagnosis and treatment preparation were preliminary explored.The results showed that functionalized nanoparticles have controllability of size and shape.The size of particles can be modulated from about 1μm to 100 nm,and particles showed three different morphology:solid,core-shell and hollow structure.In the application of drug loading,the loading efficiency is very high,and theranostic preparations can effectively kill cancer cells.This thesis successfully synthesized ZIF-8/Mn O₂ core-shell nanomaterials,which can be used as drug carriers to prepare integrated diagnosis and treatment preparations,which have great potential for development in the field of biomedicine.