Study On The Mitochondrial Imaging And Antibacterial Activity Of Metal Complexes

Mitochondria is an important organelle by producing energy and participating in many important physiological processes.During cell cycle,cell metabolism,development,differentiation and lesion,the number and morphology of mitochondria are different.Recent studies have shown that the morphology and number of mitochondria are directly related to a number of human diseases,such as cancer,neurodegenerative disease and diabetes,etc.Some reports also show that the apoptotic proteins may affect the morphology of the mitochondria.Therefore,the morphological imaging of live cell mitochondria is particularly important in the application of biomedical research and diagnosis.The optical imaging of living cells is mainly through two methods:bioluminescence(bioluminescence)and fluorescence(fluorescence).Bioluminescence is used to mark cells or genes by fluorescein(Luciferase),while fluorescence techniques are used to mark by fluorescent probes.In comparison,the fluorescence imaging technique is easy to operate,easy to observe,and has a wide range of applications.However,during the process of fluorescence imaging,the excitation of the organism’s skin,organs and food will generate endogenous fluorescence,which is non-specific fluorescence,and it greatly affects the ratio of the imaging to the noise.Although different methods have been used to eliminate this interfering fluorescence,the non specific fluorescence has not been completely eliminated because of the characteristics of the fluorescence itself.Therefore,developing new methods to eliminate the spontaneous fluorescence interference and to improve the signal-to-noise ratio of fluorescence imaging has become an urgent problem to be solved by fluorescence imaging technology.Two near-infrared luminescence Iridium(Ⅲ)metal complexes was synthesized in the second chapter and two Ruthenium(Ⅱ)metal complexes was synthesized in the third chapter.These complexes have been characterized by a series of methods,including electrospray mass spectrometric analysis,~1H NMR,X-ray diffraction,optical properties.The biological imaging process of mitochondrial localization、photobleaching and uncoupling CCCP experiment in the living cells were studied by confocal microscopy.MTT was used to detect the cytotoxicity of the complexes.And the uptake mechanism of cells was tested with flow cytometry.The subcellular distribution of complexes has been investigated by Inductively Coupled Plasma Mass Spectrometry.The study indicated that these complexes have high quantum yield、cell migration rate and stokes displacement,which is conducive to distinguish the difference of endogenous fluorescence.The complexes are fat-soluble and water-soluble,and the cell capacity is strong.Low cytotoxicity、high stability in vitro cells、high mitochondrial specificity、good light stability、good mitochondrial membrane potential and environmental pH tolerance.These excellent photophysical and imaging properties make them a promising fluorescent labeled probe for cell imaging.With the development of life science and technology,more and more biological techniques are applied to diagnosis and treatment of diseases to improve the quality of human life.Bacteria and fungi are common in nature and are closely related to human beings.By using the decomposition of microorganisms,we found bacteria that could degrade toxic substances,used for environmental pollution control,and used fungi to ferment food to transform food flavor and preserve food.But more and more reports show that some bacteria and fungi can cause serious diseases or even death in humans.Therefore,more and more attention has been paid to the research of antibacterial drugs.From early antibiotic drugs to modern synthetic antiseptic drugs,human beings have never stopped exploring antibiotics.However,many antibacterial drugs have the characteristics of narrow antimicrobial spectrum and easy to produce resistance because of the variety、complexity、fertile and mutant of bacteria.In recent years,the antibacterial activity of metal complexes has been studied in order to find antibacterial agents with strong antibacterial activity and stable properties.Five kinds of single、dual and hetero nuclear Iridium(Ⅲ)and Ruthenium(Ⅱ)complexes were synthesized in the fourth chapter of this paper.These complexes have been researched by a series of methods,containing antibacterial activity、light toxicity、Zeta potential、electron microscopy experiment and fluorescence microscopy experiment with the gram negative bacteria Escherichia coli、gram positive bacteria Staphylococcus aureus and fungi Aspergillus fumigatus.We found these five complexes have good antibacterial activity、stability、cell capacity,and located in the nucleus.It provides a powerful basis for finding new antiseptic drugs.