Introduction : L’angiogenèse tumorale conduit au développement de nouveaux vaisseaux destinés à permettre la croissance de la tumeur. Les vaisseaux tumoraux sont caractérisés notamment par des anomalies des cellules murales (cellules musculaires périvasculaires), responsables d’anomalies de la fonctionnalité et de la maturation. Dans ce travail de thèse, nous avons étudié un modèle tumoral de thérapie cellulaire par injection de cellules murales en IRM et vidéomicroscopie de fluorescence. Matériels et méthodes : Notre étude a porté sur un modèle sous cutané de carcinome épidermoïde chez la souris nude. Les animaux étaient divisés en trois groupes : contrôle (n=17), contrôle négatif (n=16) et « traité » avec injection locale de cellules murales humaines (n=17). Les animaux bénéficiaient d’une IRM et d’une exploration par vidéomicroscopie avant (J7) et après traitement (J14). Les paramètres mesurés étaient la taille tumorale (pied-à-coulisse et IRM), la densité microvasculaire (DMV par IRM, vidéomicroscopie et histologie), l’ADC, f, Dr et D* (IRM de diffusion), les variations de R2* sous air, oxygène et carbogène (IRM par effet BOLD) et « l’index leakage » (reflétant la perméabilité capillaire, en vidéomicroscopie). Résultats : Lors de la croissance tumorale, le groupe contrôle a montré une diminution des vaisseaux circulants (ou fonctionnels) qui se reflétait par une diminution du D* et du R2* sous air, une perte de la capacité à répondre au carbogène qui se reflétait par une augmentation du delta R2* sous carbogène, et une augmentation de la perméabilité capillaire qui se traduisait par un « index leakage » plus élevé. Dans le groupe traité par injection de cellules murales, nous avons observé un ralentissement de la croissance tumorale et une stabilisation de ces paramètres de microcirculation et maturation vasculaire. Conclusion : Nous avons montré un effet biologique de notre thérapie cellulaire par injection locale de cellules murales qui se traduisait par un ralentissement de la croissance tumorale, une stabilisation de l’hémodynamique microcirculatoire et de la maturation, et une perméabilité capillaire diminuée, concordants avec l’effet présumé stabilisateur et normalisateur des cellules murales sur les microvaisseaux. / Introduction : Tumor angiogenesis leads to the development of new vessels enabling the growth of the tumor. Tumor vessels are characterized by abnormalities including mural cells (perivascular muscular cells) responsible for abnormal vessel function and maturation. In this thesis, we studied cellular therapy in a tumor model by injection of mural cells using MRI and fluorescence videomicroscopy. Materiels and methods: Nude mice were injected with squamous cell TC1 tumors and animals were divided in three groups: control (n=17), sham control (n=16) and treated by local injection of human mural cells (n=17). Animals underwent MRI and videomicroscopy before (D7) and after (D14) treatment. Measured parameters included tumor size (caliper and MRI), microvessels density (MVD using MRI, videomicroscopy and pathology), ADC, f, Dr, D* (diffusion MRI), R2* variations under air, oxygen and carbogen (BOLD MRI), and ‘index leakage’ (reflecting capillary permeability, using videomicroscopy). Results: During tumor growth, the control group showed a decrease in circulating (or functional) vessels reflected by a decrease in D* and R2* under air, the loss of vessel ability to respond to carbogen reflected by an increase of the delta R2* under carbogen, and increased capillary permeability resulting in a higher ”index leakage”. In the group treated by injection of mural cells, we observed a slowing of tumor growth and stabilization of these parameters of microcirculation and vessel maturation. Conclusion : Therapy by local injection of mural cells was effective resulting in slower tumor growth, stabilization of microcirculatory hemodynamics and maturation, and decreased capillary permeability, consistent with the alleged ‘stabilizing’ and ‘normalizing’ effects of mural cells on microvessels.

Optical microscopy is the simplest and the gold standard method adopted for the screening and subsequent diagnosis of various hematological and infectious diseases like malaria, sickle cell disease, tuberculosis etc. In addition to infectious disease diagnosis, its applications range from routine blood tests to the more sophisticated cancer biopsy sample analysis. Microscopy Tests (MTs) follow a common procedural workflow: (1) A technician prepares a smear of the given sample on a glass slide in a specific manner depending on the sample and the disease to be diagnosed; (2) The smeared slide is subsequently exposed to fixative agents and different histochemical stains specific to the diagnosis to be performed and (3) the prepared slide is then observed under a high quality bright- field bench-top microscope. An expert pathologist/cytologist is required to manually examine multiple fields-of-views of the prepared slide under appropriate magnification. Multiple re-adjustments in the focus and magnification makes the process of microscopic examination time consuming and tedious. Further, the manual intervention required in all the aforementioned steps involved in a typical MT, makes it inaccessible to rural/resource limited conditions and restricts the diagnostics to be performed by trained personnel in laboratory settings. To overcome these limitations, there has been considerable research interest in developing cost-effective systems that help in automating MTs. The work done in this thesis addresses these issues and proposes a two-step solution to the problem of affordable automation of MTs for cellular imaging and subsequent diagnostic assessment. The first step deals with the development of a low cost portable system that employs custom-built microscopy setup using o -the-shelf optical components, low cost motorized stage and camera modules to facilitate slide scanning and digital image acquisition. It incorporates a novel computational approach to generate good quality in-focus images, without the need for employing high-end precision translational stages, thereby reducing the overall system cost. The process of slide analysis for result generation is further automated by using image analysis and classification algorithms. The application of the developed platform in automating slide based quantitative detection of malaria is reported in this thesis. The second aspect of the thesis addresses the automation of slide preparation. A major factor that could influence the analysis results is the quality of the prepared smears. The feasibility of automating and standardizing the process of slide preparation using Microfluidics with appropriate surface fictionalization is explored and is demonstrated in the context of automated semen analysis. As an alternative to the mechanism of fixing the spermatozoa to the glass slide by smearing and chemical treatment with fixative, microfluidic chips pre-coated with adhesive protein are employed to capture and immobilize the cells. The subsequent histochemical staining is achieved by pumping the stains through the microfluidic device. The proof-of-principle experiments performed in this thesis demonstrate the feasibility of the developed system to provide an end-to-end cost-effective alternative solution to conventional MTs. This can further serve as an assistive tool for the pathologist or in some cases completely eliminate the manual intervention required in MTs enabling repeatability and reliability in diagnosis for clinical decision making

This thesis work deals with different aspects of the chemistry of La(III) and Gd(III) complexes, their interaction with DNA and proteins, photo-induced cleavage of double-stranded DNA, photocytotoxic effect on cancer cells, cell death mechanism and cellular localization behaviour. Chapter I gives an introduction to the metal-based anticancer agents with special emphasis on clinically used drugs and the growing field of lanthanide therapeutics. An overview of the current strategies of cancer treatment, especially photodynamic therapy (PDT), is presented. Mode of small molecule-DNA interactions and the mechanistic aspects associated with DNA photodamage reactions and PDT effect are discussed with selected examples of compounds that are known to photocleave DNA on exposure to light of different wavelengths. A brief discussion on the various therapeutic applications of the lanthanide compounds is also made. Chapter II presents the synthesis, characterization, DNA binding, BSA binding, photo-induced DNA cleavage activity and photocytotoxicity of La(III) and Gd(III) complexes of phenanthroline bases to explore the UV-A light-induced DNA cleavage activity and photocytotoxicity of the complexes. Chapter III describes the synthesis, characterization, DNA binding, photo-induced DNA cleavage activity and photocytotoxicity of La(III) and Gd(III) complexes of phenanthroline bases with an aim to improve the design of the complexes to achieve better solution stability and DNA binding of the complexes. Chapter IV presents the synthesis, characterization, DNA binding, and UV-A light-induced DNA photocleavage activity and photocytotoxicity of La(III) and Gd(III) complexes of pyridyl phenanthroline bases with an objective to improve the photoactivity of the complexes by introducing an additional pyridyl group. Cell death mechanism and confocal microscopic studies are also carried out to gain more insight into the PDT effect caused by light in the presence of the complex. Chapter V describes the synthesis and characterization of La(III) and Gd(III) complexes of terpyridine bases and acetylacetonate to study the complexes as a new class of photosensitizers to explore their DNA photocleavage activity and photocytotoxicity in HeLa cells. Effect of attaching a glucose moiety to the acetyl acetone (Hacac) ligand has been studied. The cellular uptake behaviour of the La(III) pyrenyl-terpyridine complexes has also been investigated. Finally, Chapter VI presents the synthesis and characterization of curcumin and glycosylated curcumin La(III) and Gd(III) complexes having terpyridine base with an objective to study the photoactivated anticancer activity of the complexes in visible light. This chapter describes the visible light-induced DNA cleavage activity and photocytotoxicity of the complexes by exploiting curcumin and glycosylated curcumin as the photosensitizer ligands. Study on the cellular uptake behavior of curcumin La(III) complexes having pyrenyl terpyridine ligand is also presented. The references have been assembled at the end of each chapter and indicated as superscript numbers in the text. The complexes presented in this thesis are represented by bold-faced numbers. Crystallographic data of the complexes which are characterized structurally by single crystal X-ray crystallography are provided in CIF format in the enclosed CD (Appendix-I). Due acknowledgements have been made wherever the work described is based on the findings of other investigators. Any unintentional omission that might have happened due to oversight or mistake is sincerely regretted.

Les Quantum Dots (QDs) sont des particules cristallines de semi-conducteur ou du métal de forme sphérique et de dimension nanométrique. L'intérêt majeur des QDs réside dans leur grande adaptabilité à de nombreuses applications biologiques.Le but de mon travail était de développer une nouvelle classe de QDs de faible toxicité afin de les utiliser pour la bio-imagerie des cellules cancéreuses. Pour cela, il est nécessaire de préparer des sondes hydrosolubles, photostables, biocompatibles, de luminescence élevée et possédant une faible toxicité. La synthèse des cœurs de type ZnS and ZnSe dopés au manganèse ou au cuivre et stabilisés par l’acide 3-mercapropropionique ou par le 1-thioglycérol a été réalisée par la voie hydrothermale. Les techniques analytiques de caractérisation utilisées sont la spectroscopie UV-visible, la spectroscopie de fluorescence, la diffraction des rayons X (XRD), la spectroscopie photoélectronique de rayon X (XPS), la microscopie électronique à transmission (TEM), la diffusion dynamique de la lumière DLS, la spectroscopie infra-rouge (IR), et la résonance paraélectronique (RPE). La toxicité des QDs a été déterminée sur des cellules cancéreuses. Les différents test de cytotoxicité (MTT, XTT et ferrous oxidation-xylenol orange) ont été réalisés. Finalement, les QDs de type ZnS:Mn conjugués à l’acide folique ont été utilisés pour la bio-imagerie des cellules cancéreuses par le biais d’une excitation biphotonique / Semiconductor QDs are tiny light-emitting crystals, and are emerging as a new class of fluorescent labels for medicine and biology. The aim of this work was to develop a new class of non-toxic QDs probes with essential attributes such as water dispersibility, photostability, biocompatibility, high luminescence and possible excitation with low-energy visible light, using simple processing method. Such nanoprobes could be used for bio-imaging of cancer cells. In the performed studies, I focused on ZnS and ZnSe QDs as they are cadmium-free and might be excited biphotonically.The synthesis protocols of ZnS and ZnSe QDs doped with two ions such as Mn or Cu and stabilized by 3-mercaptopropionic acid or 1-thioglycerol were established, followed by NCs characterization (diameter, surface charge, photophysical properties, …) using analytical techniques such as spectrophotometry UV-vis, fluorimetry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), dynamic light scattering (DLS), infra-red analysis (FT-IR), thin layer chromatography (TLC) and electron paramagnetic resonance (EPR). The cytotoxicity of synthesized bare and conjugated NPs was evaluated on cancer cell lines using MTT, XTT and ferrous oxidation-xylenol orange assay.Finally, chosen well fluorescent and weakly toxic types of as-prepared and characterized QDs were used for bio-imaging of cancer cells. In these experiments, FA-functionalized NCs were excited biphotonically. The performed experiments showed the potential of QDs as cancer cells fluorescent markers and that they accumulate around the cell nuclei

The current thesis addresses the various facets of the chemistry of photocytotoxic iron complexes including their syntheses, characterization, evaluation of the anti-proliferative activities in various cancer cell lines upon photo-exposure, mechanism of cell death, the cellular uptake, localization inside cells, the interaction with double stranded DNA and their ability to induce DNA photocleavage. Chapter I presents a general introduction to cancer and the anticancer agents. It covers various procedures available for cancer treatment and different aspects of chemotherapy are discussed in details. The mechanism of action of several chemotherapeutic agents, the DNA cleavage pathways and the anticancer activity of bleomycins are delineated. Photo-chemotherapy or photodynamic therapy which has emerged as an alternative treatment modality is described. It also contains a brief description of ideal photosensitizers and the ones that are currently approved. The potential of transition metal complexes as photo-chemotherapeutic agents is discussed based on the recent literature reports on the prospective photocytotoxic metal complexes, the photo-release of cytotoxic molecules from metal complexes, the DNA cleavage activities and their cytotoxicities. The biochemistry of iron and its medical utility which prompted the development of iron based cytotoxins has been presented. The objective of the present investigation is also defined in this chapter. Chapter II describes the syntheses, characterization, evaluation of visible light induced cytotoxicity and interaction with DNA of a series of iron(II) bis-terpyridine complexes. Some interesting redox behaviour observed for two of the complexes has been described in details and rationalized from theoretical calculations. The DNA binding affinities of the complexes and their ability to induce DNA photocleavage in green light are discussed. The importance of this work lies in the remarkable photocytotoxic behaviour of the iron(II) complexes with visible light which was not reported earlier. Chapter III addresses the syntheses of a series of iron(III) catecholate complexes which upon irradiation with red light can initiate photoreactions to generate cytotoxic species and induce death in HeLa, HaCaT, MCF-7 and A549 cells. The mechanisms of cell death, effect of the complexes on the cell cycle under various conditions, the uptake inside cells and the cellular localization of the complexes are studied. The DNA binding affinities of the five complexes and their ability to induce DNA photocleavage in red light are also presented here. These are the first iron based complexes to show red light induced photocytotoxicity. Chapter IV addresses the drawbacks associated with the aforementioned iron(III) catecholates and their modification with a mitochondria targeting triphenylphosphonium unit. The synthesis, characterization, photocytotoxicities in HeLa, HaCaT, MCF-7 and A549, cell death mechanisms and cellular uptake and localization of four iron(III) complexes are discussed. Chapter V describes the syntheses, characterization and the biological activities of carbohydrate appended iron(III) complexes and their non-glucose analogues. The selective and faster internalization of the glyco-conjugated complexes in HeLa cells has been studied using various spectroscopic and microscopic techniques. The red light induced cytotoxicities of the complexes, their effect on the progression of the cell cycle with and without irradiation and the mechanisms of cell death are explored. DNA binding abilities and photocleavage of DNA are also discussed. Chapter VI presents the syntheses, characterization of a series of iron(III) complexes of a pyridoxal derivative and their salicyldehyde analogues for exploring their differential photocytotoxicity and cellular uptake in cancer cells compared to normal cells. The visible light induced cytotoxicities of the complexes in HeLa, HaCaT, MCF-7 A549 cells and HPL1D cells, their effect on the progression of the cell cycle in dark and light, the mechanisms of cell death and the localization of the complexes inside the cells are explored. The references have been compiled at the end of each chapter and given as superscripts in the text. The complexes presented in this thesis are indicated by bold-faced numbers. Crystallography data of the complexes that are structurally characterized by single crystal X-ray crystallography are given in CIF format in the enclosed CD (Appendix-I). Due acknowledgements have been made wherever the work described is based on the findings of other investigators. Any unintentional omission that might have happened due to oversight is regretted. INDEX WORDS: Iron complexes • Crystal structure • Red light induced cytotoxicity • Cellular imaging • DNA binding • DNA photocleavage.