La bis(phosphine) non symétrique Ph2P(CH2)2P(CH2OH)2 a été conçue et synthétisée afin d’imiter la tris(hydroxyméthyl)phosphine, une structure intéressante pouvant être utilisée en catalyse avec des métaux de transition car elle peut changer la sphère de coordination de ceux-ci. Si l’hydroxyméthylphosphine est liée à une donneur de diphénylphosphine possédant un pont éthane-1,2-diyl, ce dernier devrait permettre d’augmenter la stabilité du complexe à travers son effet chélatant, pour fournir un complexe mieux défini. Afin de comprendre l’origine de phénomènes indésirables provenant d’hydroxy-méthylphosphines, nous avons également synthétisé leurs analogues munis des fonctions bis(méthoxyméthyl)phosphine et aminométhylphosphines ainsi que les 2,6-dihydroxy-phosphinanes. Ces bis(phosphines) ont été utilisées pour former des complexes avec différents métaux de transition (Co(II), Ni(II), Ru(II), Rh(I), Pd(II), et Pt(II)). Il est à noter que des effets de liaisons hydrogènes ont sur la stéréochimie ont été observés, et que des arguments provenant de la littérature concernant la coordination d’hydroxyméthylphosphines ont été réfutés. Certains complexes possèdent également une activité cytotoxique importante envers des cellules cancéreuses humaines. Les ligands ont également été employés avec succès en catalyse, avec du rhodium pour réaliser des hydrogénations d’enamides et avec des métaux du groupe 10 pour effectuer l’hydro-phosphination du formol par PH3. / The non-symmetrical bis(phosphine) Ph2P(CH2)2¬P(CH2OH)2 was designed and synthesized as a mimic of tris(hydroxymethyl)phoshine; this structure is appealing for use in transition metal catalysis but is known to show unpredictable reactivity in transition metal coordination spheres. Having a hydroxymethylphosphine connected to a conventional diphenylphosphine donor with an ethane-1,2-diyl bridge should provide increased stability through the chelate effect and thus better-defined coordination complexes. To obtain data concerning the origin of the undesired acitivity of hydroxymethylphosphines, we also synthesized aprotic bis(methoxy) and aminomethylphosphine and cyclic dihydroxyphosphinane analogues of the non-symmetrical bis(phosphine). These bis(phosphines) have been used to form coordination complexes with a number of transition metals (Co(II), Ni(II), Ru(II), Rh(I), Pd(II), and Pt(II)). Significant hydrogen bonding influence on stereochemistry were observed and some arguments regarding hydroxymethylphosphine coordination in the literature were refuted. A selection of the complexes has also been shown to possess significant cytotoxic activity against a human cancer cell line. The ligands have also been employed successfully as ligands in two catalytic systems, viz. RhI catalysed hydrogenation and group 10 metal catalysed hydrophosphination of formaldehyde.

Indiana University-Purdue University Indianapolis (IUPUI) / The Gram-negative bacterium Pseudomonas aeruginosa causes numerous acute and chronic opportunistic infections in humans. One of its most formidable weapons is a type III secretion system (T3SS), a multi-protein molecular syringe that injects powerful toxins directly into host cells. The toxins lead to cell dysfunction and, ultimately, cell death. Identification of regulatory pathways that control T3SS gene expression may lead to the discovery of novel therapeutics to treat P. aeruginosa infections. In a previous study, it was found that expression of the magnesium transporter gene mgtE inhibits T3SS gene transcription. MgtE-dependent inhibition appeared to interfere with the synthesis or function of the master T3SS transcriptional activator ExsA, although the exact mechanism was unclear. In this work, we demonstrate that mgtE expression acts through the GacAS two-component system to activate transcription of the small regulatory RNAs RsmY and RsmZ. This event ultimately leads to inhibition of exsA translation. Moreover, our data reveal that MgtE acts solely through this pathway to regulate T3SS gene transcription. Our study reveals an important mechanism that may allow P. aeruginosa to fine-tune T3SS activity in response to certain environmental stimuli. In addition, a previous study has shown that the P. aeruginosa gene algR abrogates mgtE mediated regulation of cytotoxicity. AlgR has pleiotropic effects in P. aeruginosa, including regulation of synthesis of the exopolysaccharide alginate. In the second part of my thesis, I show that algR and mgtE genetically crosstalk to inhibit ExsA driven T3SS gene transcription. This genetic interaction between algR and mgtE seems to be specifically directed towards regulation of T3SS gene expression rather than having an indiscriminate effect on multiple virulence attributes in P. aeruginosa. Additionally, we have further demonstrated that AlgR inhibits mgtE transcription. These studies suggest the presence of a T3SS inhibitor that is inhibited by both AlgR and MgtE. Future work will involve transcriptomic and proteomic analysis to identify such an inhibitor. Taken together, this study provides important insight into the molecular mechanisms of mgtE expression and function in P. aeruginosa. We have established that mgtE has pleiotropic effects on cytotoxicity in P. aeruginosa. Thus, given the role that cytotoxicity regulation plays in shaping P. aeruginosa pathogenesis and associated clinical outcomes, mgtE might be an interesting drug target, though extensive future studies are required to validate this proposition. Nevertheless, this research, provides clues for identification of novel therapeutic targets in P. aeruginosa. Hence this work, in the long run, serve to ameliorate the morbidity and mortality in patients infected with P. aeruginosa.

Trichomoniasis is a common STD caused by the parasitic protozoan Trichomonas vaginalis. The parasite is estimated to have infected roughly 3.7 million Americans. Complications from trichomoniasis can lead to cervical cancer in women and prostate cancer in men. One of the mechanisms of the parasite employs is using cysteine proteases to break down the cellular matrix of its host. However, three endogenous phytocystatin-like protease inhibitors have been found within the parasite’s genome. By recombinantly expressing these cystatins we have been able to test their ability to inhibit cysteine proteases such as papain and those found in T. vaginalis to find their effectiveness. By characterizing these inhibitors, it appears that they are effective at reducing the ability of T. vaginalis cysteine proteases and thus could be useful against the pathogenicity of the parasite.

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Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Bc. Marie Zádrapová Supervisor: RNDr. Jana Maixnerová, Ph.D. Title of diploma thesis: Determination of renal toxicity of antineoplastics in vitro BRAF inhibitors are important antineoplastics. They work on the principle of inhibition of certain types of protein kinases and turned out to be very efficient for the treatment of melanoma. One of their disadvantages is relatively early onset of resistance; thus, it is important to look for new combinations of drugs that are already in use or work on the development of new structures with similar inhibition efficacy on melanoma cells. Encorafenib and its combination with binimetinib have been shown to be very promising drugs from the group of BRAF inhibitors, however, potential renal toxicity may be a therapeutic limitation. This thesis was focused on the determination of in vitro cytotoxicity of encorafenib on different types of renal cells in three time intervals and on its comparison with two drug standards - amphotericin B and paracetamol. Three types of morphologically and functionally different kidney cells (PODO / TERT256, HK-2 and HEK293) were used for this purpose. The cytotoxic potential was measured by colorimetric method CellTiter 96®...

Natural IgM producing phagocytic B cells (NIMPABs) are a rare population of immune cells that can produce antibodies to broadly target and eliminate cancer cells via phosphatidylcholine (PtC)-specific phagocytosis. A novel, dual-labeled lipid-shelled superparamagnetic iron oxide nanoparticle (SPION)-based (SLNP) system was developed to trigger specific phagocytotic behavior in and subsequent enrichment of NIMPABs for a potential immunotherapy. Here we propose the design of an in vitro model to assess cell-SLNP interactions with J774A.1 monocyte cell line and the optimization of SLNP formulation. First, we developed and examined the morphology, size, concentration, purification, sterilization, and storage conditions of oleylamine-coated SPIONs and SLNPs using various microscopy methods, spectroscopy, dynamic light scattering, and zeta potential. Our data confirmed SPIONs are magnetic and 7-8 nm in diameter. SLNPs containing SPIONs retained the magnetic property, and are typically measured between 100-120 nm in diameter, and had a positive zeta potential. Fluorescence labeling of the SLNPs did not affect their properties. Second, we examined cytotoxicity and phagocytosis of SLNPs with J774A.1 cells. Our preliminary data showed that significant percentage of phagocytosis can be observed as early as 2 hours. However, longer than 2 hour incubation resulted in significant cytotoxic effects. The source of SLNP cytotoxicity was examined with transmission electron microscopy and characterization techniques, identifying high un-encapsulated free oleylamine-coated SPION content in SLNP samples contributing to a positive zeta potential for these samples. Simplified SLNPs with oleic acid-coated SPIONs were synthesized and resulting examined particles had a negative zeta potential, reduced free SPION content and improved SPION incorporation into SLNP cores. Based on these findings, SLNP criteria, characterization techniques, and cell assays were revised to establish a rigorous, standardized workflow essential for determining the optimal SLNP formulation. Future work must continue to modify SLNP formulation with information obtained from all characterization techniques and cellular assays outlined in the in vitro model. Once optimized, selective SLNP-mediated isolation of NIMPAB cells can be validated ex vivo with murine peritoneal cavity washout cells and then human peripheral blood samples. / 2024-08-26T00:00:00Z

Statins, hydroxymethylglutaryl-coenzyme-A reductase inhibitors (HMG-Co-A), are known to reduce plasma cholesterol levels. Interestingly, Simvastatin was previously reported to have a positive effect on the proliferation and odontoblastic differentiation of human dental pulp cells. However, the biocompatibility of Simvastatin has not been studied thoroughly. The purpose of this study was to further compare the effectiveness of different concentrations of Simvastatin on the attachment, proliferation, differentiation, toxicity, mineralization, and flow cytometry of human dental pulp cells (HDPCs) and osteoblasts. HDPCs and osteoblasts were cultured with Simvastatin at various concentrations of 1, 10, 25, 50, 75, 100 μmol/L, and 0 μmol/L was used as a control. The cell attachment was evaluated at 16 hours for HDPCs and 9 hours for osteoblasts. The proliferation rate, differentiation, cytotoxicity, and mineralization were investigated at 7, 14 and 21 days. Cell cycle and apoptosis were assessed at 1 and 3 days. Statistical analysis was performed using ANOVA. P-values ≤0.05 were considered statistically significant. The results showed that 25 μmol/L demonstrated the highest cell attachment efficiency when compared to the control in HDPCs (P<0.05). There was no statistical significance (P>0.05) amongst the groups in the cell attachment efficiency in osteoblasts. All tested concentrations showed a significant decrease in the proliferation rate and mineralization (P<0.001) and an increase in cytotoxicity and cytostasis (P<0.001) in both cell types. ALP levels increased in HDPCs and osteoblasts (P<0.001). DSP and RUNX2 levels decreased in HDPCs (P<0.001). OSC levels were increased in osteoblasts, but RUNX2 was decreased (P<0.001). Cell cycle and apoptosis significantly increased as time increased (P<0.001) in both cell types. In conclusion, the present findings showed that Simvastatin adversely affects the proliferation, cell viability of HDPCs and osteoblasts by inducing apoptosis, which were confirmed by flow cytometry results. There was an increase in the odontogenic and osteogenic markers hinting at early differentiation, which decreased as time increased. / 2025-07-10T00:00:00Z

This thesis describes a new method for the synthesis of pseudodisaccharides containing a carbasugar analogue attached to a "true" sugar. The methodology is based on a Diels-Alder cycloaddition of vinyl sugars and appropriately substituted pyran-2-ones, followed by chemical manipulation of the resulting cycloadducts. The thesis also describes the synthesis of inhibitors of Golgi ¿-mannosidase II and glucokinase. The first chapter is a comprehensive survey of the reported synthetic routes to pseudodisaccharides from the literature. The results and discussions are presented in chapter 2. This chapter starts by discussion of the preparation of vinyl sugars and pyran-2-ones and the regio- and stereoselectivity of their cycloadditions. This is followed by reporting the chemical manipulations of these cycloadducts and the synthesis of a pseudodisaccharide. Cycloadducts are shown to lose carbon dioxide at elevated temperatures to afford dihydrobenzenes. The loss of the bridging carbon dioxide from the cycloadducts is experimentally and computationally investigated. The resulting dihydrobenzenes are shown to also be useful as precursors in the synthesis of pseudodisaccharides. The chemical manipulation of these dihydrobenzenes is used towards the synthesis of a pseudodisaccharide. The third and fourth chapters focus on the synthesis of new inhibitors of Golgi ¿-mannosidase II and glucokinase respectively. A range of 6-aminoglucose and mannose derivatives were prepared and tested for the inhibition of Jack bean ¿-mannosidase, but were found to lack any inhibition. Similarly, a range of 6-triazologlucose derivatives were prepared but were found to lack any cytotoxicity. The fifth chapter contains the details of the preparation, experimental procedures and spectroscopic characterisation of the synthesised chemical compounds. Rate calculations are reported in Appendix I and the X-ray crystallographic data are presented in the Appendix II.

The aim of this research was to investigate the phytochemistry of two species Sanicula europaea and Teucrium davaeanum which are traditionally used in treatment of wounds. Four compounds were isolated from the 80% methanolic extract of S. europaea; bis-(2-ethylhexyl) phthalate (1), palmitic acid (2), rosmarinic acid (3), saniculoside N (4). Compounds 1 and 2 were isolated for the first time from this species. The structure elucidation of the isolated compounds was on the basis of 1D, 2D NMR spectroscopy and mass spectrometry measurements. Two compounds were isolated from the crude glycosides extract of T.davaeanum; 6 is a phenylethanoid glycoside and 8 is an iridoid glycoside, from the data available these may be new compounds for which the names davaeanuside A and davaeanuside B are proposed respectively." The total polyphenol content of S. europaea L, T. davaeanum leaves-flowers and T. davaeanum stem were found to be 5.0, 1.20 and 0.65 mg per 100 mg dried plant material respectively. A study of the antioxidant activity of the 50 % ethanol extracts of S. europaea and T. davaeanum showed that on a mg/mg basis S. europaea and T. davaeanum have approximately 5%, 8 % antioxidant capacity of Trolox respectively. A study of the cytotoxic activity of davaeanuside A (6), iridoid glycoside (7), davaeanuside B (8) and saponin compound (10) isolated from the crude glycosides extract of T. davaeanum revealed that saponin compound (10) inhibited the growth of Hela cells by 50 % at 50 μg/ml, P< 0.001, but the other compounds did not show activities against the tested cell lines at 100 μg/ml. The results of this work provide some basis for the traditional use of these species in the treatment of wounds. / Ministry of high education in Libya

The use of nanowires, nano and micro needles in biomedical applications has markedly increased in the past years, mainly due to attractive properties such as biocompatibility and simple fabrication. Specifically, these structures have shown promise in applications including cell separation, tumor cell capture, intracellular delivery, cell therapy, cancer treatment and as cell growth scaffolds. The work proposed here aims to study two platforms for different applications: a vertical magnetic nanowire array for mesenchymal stem cell differentiation and a micro needle platform for intracellular delivery. First, a thorough evaluation of the cytotoxicity of nanowires was done in order to understand how a biological system interacts with high aspect ratio structures. Nanowires were fabricated through pulsed electrodeposition and characterized by electron microscopy, vibrating sample magnetometry and energy dispersive X-ray spectroscopy. Studies of biocompatibility, cell death, cell membrane integrity, nanowire internalization and intracellular dissolution were all performed in order to characterize the cell response. Results showed a variable biocompatibility depending on nanowire concentration and incubation time, with cell death resulting from an apoptotic pathway arising after internalization. A vertical array of nanowires was then used as a scaffold for the differentiation of human mesenchymal stem cells. Using fluorescence and electron microscopy, the interactions between the dense array of nanowires and the cells were analyzed, as well as the biocompatibility of the array and its effects on cell differentiation. A magnetic field was additionally applied on the substrate to observe a possible differentiation. Stem cells grown on this scaffold showed a cytoskeleton and focal adhesion reorganization, and later expressed the osteogenic marker osteopontin. The application of a magnetic field counteracted this outcome. Lastly, a micro needle platform was fabricated through lithography and electrodeposition, characterized using the previously mentioned techniques and then evaluated as a vector for intracellular delivery. Fluorescence and electron microscopy imaging were first performed to assess the biocompatibility, cell spreading and the interface of the cells and the needles. Intracellular delivery of a fluorescent dye was achieved via inductive heating of the needles, with the results showing a dependency of delivery and cell survivability on the exposure time.