75 results on '"Papi R"'
Search Results
2. Biocompatible silver(I) complexes with heterocyclic thioamide ligands for selective killing of cancer cells and high antimicrobial activity – A combined in vitro and in silico study
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Varna, D. Geromichalou, E. Papachristou, E. Papi, R. Hatzidimitriou, A.G. Panteris, E. Psomas, G. Geromichalos, G.D. Aslanidis, P. Choli-Papadopoulou, T. Angaridis, P.A.
- Abstract
A series of heteroleptic Ag(I) complexes bearing 4,6-dimethyl-2-pyrimidinethiol (dmp2SH), i.e., [AgCl(dmp2SH)(PPh3)2] (1), [Ag(dmp2SH)(PPh3)2]NO3 (2), [Ag(dmp2SΗ)(xantphos)]NO3 (3), [Ag(μ-dmp2S)(PPh3)]2 (4), [Ag(dmp2S)(xantphos)] (5), [Ag(μ-dmp2S)(DPEphos)]2 (6) (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and DPEPhos = bis[(2-diphenylphosphino)phenyl]ether) were synthesized. The complexes display systematic variation of particular structural characteristics which were proved to have a significant impact on their in vitro cytotoxicity and antimicrobial properties. A moderate-to-high potential for bacteria growth inhibition was observed for all complexes, with 2, 3 and 5 being particularly effective against Gram-(+) bacteria (IC50 = 1.6–4.5 μM). The three complexes exhibit high in vitro cytotoxicity against HeLa and MCF-7 cancer cells (IC50 = 0.32–3.00 μΜ), suggesting the importance of coordination unsaturation and cationic charge for effective bioactivity. A very low cytotoxicity against HDFa normal cells was observed, revealing a high degree of selectivity (selectivity index ~10) and, hence, biocompatibility. Fluorescence microscopy using 2 showed effective targeting on the membrane of the HeLa cancer cells, subsequently inducing cell death. Binding of the complexes to serum albumin proteins is reasonably strong for potential uptake and subsequent release to target sites. A moderate in vitro antioxidant capacity for free radicals scavenging was observed and a low potential to destroy the double-strand structure of calf-thymus DNA by intercalation, suggesting likely implication of these properties in the bioactivity mechanisms of these complexes. Further insight into possible mechanisms of bioactivity was obtained by molecular modeling calculations, by exploring their ability to act as potential inhibitors of DNA-gyrase, human estrogen receptor alpha, human cyclin-dependent kinase 6, and human papillomavirus E6 oncoprotein. © 2021
- Published
- 2022
3. Genetic variation of Fraxinus angustifolia natural populations in Greece based on nuclear and chloroplast microsatellite markers
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Papi, R. M., Spanos, K. A., and Kyriakidis, D. A.
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- 2012
- Full Text
- View/download PDF
4. Bedreigende en kalmerende invloeden op vermoeidheid
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Overgaauw, E, Reerds, Z.E.C., Pino, T., Prent, Y., Papi, R., Anagnostaki, E., Schelwald, R., Geenen, R., Leerstoel Geenen, and Clinical Psychology (onderzoeksprogramma)
- Abstract
In een onderzoek van de Universiteit Utrecht gaven mensen met Myalgische Encefalomyelitis/Chronisch vermoeidheidssyndroom (ME/CVS) aan welke bedreigende en kalmerende invloeden op vermoeidheid ze ondervonden. ‘Weinig tijd om te rusten’, ‘slecht slapen’ en ‘over de eigen grenzen gaan’ bleken de grootste bedreigingen. Het meest kalmerend bleken ‘de vrijheid hebben om iets te doen zoals men het zelf wil doen’, ‘in een rustige omgeving zijn’ en ‘rust of een pauze nemen’. De ervaringen van mensen verschilden echter enorm; wat voor de ene persoon een bedreiging of kalmering is, hoeft dat nog niet voor een ander te zijn.
- Published
- 2020
5. Bedreigende en kalmerende invloeden bij fibromyalgie
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Geenen, R., Overgaauw, E, Papi, R., Reerds, Z.E.C., Schelwald, R., Pino, T., Anagnostaki, E., Prent, Y., Leerstoel Geenen, and Clinical Psychology (overkoepelend voor heel KP)
- Abstract
‘Over je grenzen gaan’, ‘lichamelijke symptomen’, en ‘slecht slapen’ bleken de grootste bedreigingen in een onderzoek van de Universiteit Utrecht. ‘Een goede balans tussen inspanning en ontspanning’, ‘rust of een pauze nemen’ en ‘een rustige omgeving’ werden het meest kalmerend genoemd. De ervaringen van mensen verschilden echter enorm; wat voor de ene persoon een bedreiging of kalmering is, is dat nog niet voor een ander.
- Published
- 2020
6. Kwetsbaarheid en weerbaarheid bij PDS
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Geenen, R., Prent, Y., Pino, T., Anagnostaki, E., Papi, R., Schelwald, R., Reerds, Z.E.C., Overgaauw, E, Leerstoel Geenen, and Clinical Psychology (overkoepelend voor heel KP)
- Abstract
In een onderzoek van de Universiteit Utrecht gaven mensen met het Prikkelbare Darm Syndroom (PDS) aan welke invloeden ze als bedreigend en kalmerend voor hun lichamelijke symptomen ervaarden en wat ze motiveerde in het leven. De ervaringen van patiënten bleken enorm te verschillen.
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- 2020
7. Kwetsbaarheid en weerbaarheid bij PDS
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Leerstoel Geenen, Clinical Psychology (overkoepelend voor heel KP), Geenen, R., Prent, Y., Pino, T., Anagnostaki, E., Papi, R., Schelwald, R., Reerds, Z.E.C., Overgaauw, E, Leerstoel Geenen, Clinical Psychology (overkoepelend voor heel KP), Geenen, R., Prent, Y., Pino, T., Anagnostaki, E., Papi, R., Schelwald, R., Reerds, Z.E.C., and Overgaauw, E
- Published
- 2020
8. Bedreigende en kalmerende invloeden bij fibromyalgie
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Leerstoel Geenen, Clinical Psychology (overkoepelend voor heel KP), Geenen, R., Overgaauw, E, Papi, R., Reerds, Z.E.C., Schelwald, R., Pino, T., Anagnostaki, E., Prent, Y., Leerstoel Geenen, Clinical Psychology (overkoepelend voor heel KP), Geenen, R., Overgaauw, E, Papi, R., Reerds, Z.E.C., Schelwald, R., Pino, T., Anagnostaki, E., and Prent, Y.
- Published
- 2020
9. Bedreigende en kalmerende invloeden op vermoeidheid
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Leerstoel Geenen, Clinical Psychology (onderzoeksprogramma), Overgaauw, E, Reerds, Z.E.C., Pino, T., Prent, Y., Papi, R., Anagnostaki, E., Schelwald, R., Geenen, R., Leerstoel Geenen, Clinical Psychology (onderzoeksprogramma), Overgaauw, E, Reerds, Z.E.C., Pino, T., Prent, Y., Papi, R., Anagnostaki, E., Schelwald, R., and Geenen, R.
- Published
- 2020
10. Characterization of genes with biotechnological relevance from Thermus thermophilus HB8: B5.43
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Papi, R., Filippou, P., and Kyriakidis, D.
- Published
- 2010
11. Xanthan gum and ethanol production by Xanthomonas campestris and Zymomonas mobilis from peach pulp
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Papi, R. M., Ekateriniadou, L. V., Beletsiotis, E., Typas, M. A., and Kyriakidis, D. A.
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- 1999
- Full Text
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12. Dinuclear copper(I) complexes of N-methylbenzothiazole-2-thione: synthesis, structures, antibacterial activity and DNA interaction
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Varna, D., primary, Psomas, G., additional, Choli-Papadopoulou, T., additional, Papi, R., additional, Hatzidimitriou, A. G., additional, and Aslanidis, P., additional
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- 2016
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13. Synthesis of Na-hydrazino- and Aza-peptoids based on substance P: C-terminal fragments and their trypsin inhibitory effect
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Ziovas, M., Vakalopoulou, P., Glezakos, P., Papi, R., Stavropoulos, G., and Kyriakidis, D.A.
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Χημεία ,Chemistry ,Βιολογία ,Biology - Abstract
Journal URL: http://www.springerlink.com/content/104405/ Abstract Serine protease inhibitors (Serpins) is a group of proteins with similar structures, which were first identified as a set of proteins able to inhibit proteases function. The human plasma proteins antithrombin and antitrypsin, which play key roles in controlling blood coagulation and inflammation, respectively, were the first members of the serpins superfamily to be extensively studied. Trypsin-like serine proteases are essential for many biological processes. Because of this a large number of synthetic peptides have been designed and synthesized, based on the structure of inhibitors, active against trypsin or chymotrypsin. In the present work we have synthesized a series of Na-hydrazinopeptoids and aza-peptoids and studied their trypsin inhibitory effect. These peptidomimetics are expected to show enhanced metabolitic stability and bioavailability in comparison with natural parent peptidic analogs. All the syntheses were carried out stepwise by SPPS, using the Fmoc/ But methodology on the solid support 2-chlorotrityl chloride resin and DIC/HOBt as coupling reagent. The products were purified (HPLC) and identified (ESI-MS). Their inhibitory effect against trypsin activity has partly measured, while other compounds are under investigation.
- Published
- 2010
14. Biotyping of Brucella melitensis by multi-locus analysis of variable number tandem repeats (VNTRs)
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Noutsios, G. A., Papi, R. M., Aikateriniadou, L. V., Minas, A., and Kyriakidis, D.A.
- Abstract
Journal URL: http://www3.interscience.wiley.com/journal/119877016/tocgroup Brucella spp. are gram-negative intercellular pathogens that infect a variety of domestic and wild animals. Brucella melitensis causes brucellosis to sheep, cattle and humans as a secondary host. It continues to be of great health significance and economic importance in many European countries. Differentiation between species and their different biovars is currently based on serotyping, phage typing, biochemical characteristics, metabolic properties and dye-sensitivity. The finger printing method was implemented using microsatellite DNA to genotype B. melitensis. An eight-base pair tandem repeat sequence was discovered in eight genomic loci of the B. melitensis genome and it was found that existed in various, multiple and accidental repetitions. Specific primers were used to amplify these particular loci. The PCR products were analysed in LI-COR IR2 DNA Sequencer and their molecular size was determined. We studied 45 contagious samples of the Greek peninsula. Out of the nine loci studied for all samples only five exhibit differences and thus biotyping of B. melitensis was achieved.
- Published
- 2008
15. The role of different ions in molecular recognition process of C-terminal cholecystokinin pentapeptide in polymeric receptors
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Papaioannou, E., Liakopoulou-Kyriakides, M., Papi, R., and Kyriakidis, D.A.
- Abstract
Journal URL: http://www.springer.at/amino_acids The production of molecularly imprinted polymers (MIPs) for the recognition of C-terminal cholecystokinin pentapeptide (CCK-5P) in the presence or absence of metal ions is reported. Metal ions play an important role in recognition process allowing the monomers to assemble around the template in protic solvents by ligand formation. The MIPs were prepared under the same molar ratio of template to monomers (acrylamide N N0-methylene bisacrylamide) in the presence or absence of nitriloacetic acid nickel complex (Ni-NTA). Subsequently the produced Ni-NTA polymers were washed with EDTA (pH 8) to remove the Ni2ώ and incubated in aqueous solution of MgSO4 FeSO4 ZnSO4 CoSO4 or CuSO4 respectively at initial concentration 20mM in order to examine the contribution of these ions to recognition process. From the rebinding data a Langmuir adsorption isotherm was obtained for each metal ion used and the subsequent Scatchard plot analysis showed that the above ions exhibited different dissociation constant values KD. It was found that polymers containing the metal ion complex with the order Fe-NTA Ni-NTA and Cu-NTA gave lower dissociation constant values and thus exhibit the stronger guest binding activity. The percentage of theoretical maximum binding sites Bmax is almost constant for these ions meaning that the ion-template coordination is responsible for their binding strength and not for the number of active sites.
- Published
- 2008
16. Directed mutagenesis on the gene of coagulation factor IX and their effect on the proteolytic activity
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Iskas, M. S., Papi, R. M., Rafailidis, S. P., Makris, P. E., and Kyriakidis, D.A.
- Abstract
Journal URL: http://www.springer.at/amino_acids Abstract In this study site-directed mutagenesis was performed on coagulation factor IX (fIX) gene and their effect on the protein’s proteolytic activity was studied. Blood coagulation factor IX (fIX) is a vitamin K-dependent plasma serine protease that plays a major role in coagulation mechanism and haemostasis. It is synthesized in hepatocytes as a precursor protein of 461 amino acids. After several post-translational modifications the mature protein is secreted in the circulation as inactive zymogen. The zymogen is then activated during the coagulation cascade into an active serine protease. A truncated form of fIX gene (rf9) inserted in a pET22b vector was used in our experiments so as to be able to overexpress the protein in prokaryotic cells. Two mutations were induced on this gene. Both of them are described in databases as polymorphisms. The first one (A21975G) is on the protein’s activation peptide and causes the substitution of Thr194 by an Ala residue. The prevalence of this G containing allele in general population is 23%. However in our previous study we found that in a certain group of thrombophilic patients the prevalence of the G containing allele was 50%. The second mutation (A32881C) is also described as polymorphism and causes the substitution of Thr461 by a Gly residue and involves the 2% of the population. Both mutated and native forms of the truncated coagulation factor IX (rf9) were overexpressed in E. coli BL21 cells after induction with IPTG. The truncated factor rf9 lacks its first N-terminal domains; therefore it doesn’t require posttranslational modifications in order to gain activity. Proteolytic activity of rf9 was studied using an amidolytic assay. Rf9 was first activated using Russell’s viper venom FX activating protein (RVV-X). The specific tripeptide MSD- Phe-Gly-Arg-pNA was used as a substrate. Proteins were purified from the cytoplasm using a Q-Sepharose ff column. They were activated and their proteolytic activity was studied. A difference in the activity of the two mutants was observed compared to the native protein thus a correlation of the two mutations and factor’s activity was attempt.
- Published
- 2008
17. Selective recognition and separation of amino acids by molecularly imprinted polymers
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Trikka, F. A., Papi, R. M., and Kyriakidis, D.A.
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macromolecular substances - Abstract
Journal URL: http://www.springer.at/amino_acids Molecularly imprinted polymers (MIPs) are smart tailored-made materials used for the sensitive and selective recognition of small molecules and=or biologically important substances. The target molecule acting as a molecular template is copolymerized with an excess of afunctional monomer and a cross-linker. The template is entrapped in the formed polymer and following its removal complementary cavities in structure and in properties to the template are formed in the polymer. Consequently the polymer is able to rebind the template molecule with high affinity and specificity. The chemical and physical stability of MIPs in both aqueous and organic solvents their resistance at extreme pH and temperature conditions and their reusability revealed their promising applications in the field of biocatalysis diagnostics immunoassays bioseparations biomimetic sensors affinity chromatography while imprinting molecules of biological origin such as amino acids oligopeptides and even proteins have gained great attention. In this study a number of molecularly imprinted polymers (MIPs) have been produced via non-covalent imprinting for L-methionine and L-lysine and screened for their rebinding characteristics. The MIPs were produced with alterations in the molar ratio of template:monomer: cross-linker and the rebinding affinity for both amino acids was evaluated by guest batch-wise rebinding experiments. The percentage of net rebinding and the imprinting factors were used for the measurement of imprinting efficacy. Scanning electron microscopy images of MIPs and BET specific surface area measurements were obtained in an attempt to correlate the adsorption characteristics with polymer morphology. In the case of L-methionine the MIPs that were produced presented better characteristics indicated that these polymers may be used in the solid phase extraction of L-methionine or for diagnostics assays. Further experiments need to be performed for the molecularly imprinting of L-lysine to facilitate better rebinding characteristics of the polymers.
- Published
- 2008
18. Identification of PHA loci in Thermus thermophilus HB8 genome
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Papi, R. M., Mimikakou, G. E., Pantazaki, A. A., and Kyriakidis, D.A.
- Abstract
Poster Presentation Journal URL: http://www3.interscience.wiley.com/journal/119877016/tocgroup Polyhydroxyalkanoic acids (PHAs) are carbon and energy storage polymers synthesized by most eubacteria and archea in response to environmental conditions. The PHA biosynthetic bacteria are classified into four groups based on the organization of the pha gene locus and the structure-function properties of the PHA synthases. Synthases are the key enzymes in the biosynthesis of PHA and catalyse the stereoselective conversion of (R)-3-hydroxyacyl-CoA substrates to PHAs. Recently we have published the purification and characterization of a PHA synthase from Thermus thermophilus HB8 [1]. Although the entire genome of T. thermophilus has been published [2] a large number of ORFs still remains as hypothetical proteins. In this study PCR-based methods were employed for the identification of pha biosynthesis genes in T. thermophilus genome. For pha loci amplification the LA Taq polymerase was used and genomic DNA isolated from the bacterial cells. The primers were designed based on the highly conserved nucleic acid sequences in regions of the class II pha loci of various Pseudomonas. PCR products were sucloned into PCRII and later into pUC19. Escherichia coli JM109 were transformed with the constructed plasmids and screened for PHA synthase activity. Three putative regions were identified and studied further. The amplification pattern indicates that T. thermophilus HB8 belongs to class II pha loci. Elucidation of the mechanism of PHA biosynthesis in a thermophilic microorganism may lead to polymers with improved properties of high biotechnological value
- Published
- 2008
19. Artificial receptor for peptide recognition in protic media:the role of metal ion coordination
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Papaioannou, E. H., Liakopoulou-Kyriakides, M., Papi, R. M., Kyriakidis, D. A., Papaioannou, E. H., Liakopoulou-Kyriakides, M., Papi, R. M., and Kyriakidis, D. A.
- Abstract
The production of molecularly imprinted polymers (MIPs) for the recognition of C-terminal cholecystokinin pentapeptide (CCK-5) in the presence of metal ion is reported. The MIPs were produced under the same molar ratio of template to monomers (acrylamide, N,N′-methylene bisacrylamide) in the presence or absence of nitrilotriacetic acid-nickel (Ni-NTA) complex. Scanning electron microscopy images of MIPs were obtained in an attempt to correlate the adsorption characteristics with polymer's morphology. Subsequently Ni2+ was removed and substituted by other divalent ions such as Mg2+, Fe2+, Zn2+, Co2+ and Cu2+. It was found that polymers containing the metal ion complex with the order Fe-NTA, Ni-NTA and Cu-NTA presented lower dissociation constant values than the rest thus exhibiting stronger guest binding activity. The percentage of theoretical maximum binding sites Bmax was almost the same for these ions, indicating that the ion-template coordination is responsible only for their binding strength and not for the number of active sites. The data showed that the proper ion or the ion exchange in the produced MIPs could lead to materials with interesting recognition abilities regarding CCK-5 or/and other isoforms of CCK hormone.
- Published
- 2008
20. Genetic variation of Fraxinus angustifolia natural populations in Greece based on nuclear and chloroplast microsatellite markers
- Author
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Papi, R. M., primary, Spanos, K. A., additional, and Kyriakidis, D. A., additional
- Published
- 2011
- Full Text
- View/download PDF
21. P-8 Preclinical Cardiac Involvement In Progressive External Ophthalmoplegia
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Franzoni, F., Galetta, F., Orsucci, D., Mancuso, M., Ricci, G., Tocchini, L., Guidotti, E., Papi, R., Siciliano, G., and Santoro, G.
- Subjects
Poster Presentations - Published
- 2011
22. P-3 Exercise intolerance in Mc Ardle Disease: functional and metabolic evaluation
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Bertolucci, F., Ricci, G., Papi, R., Franzoni, F., Galetta, F., Bigalli, G., Zecca, M.C., Tartarisco, G., Masoni, C., Lo Gerfo, A., and Siciliano, G.
- Subjects
Poster Presentations - Published
- 2011
23. Biological activities of iridoids from Scutellaria rupestris ssp. adenotricha
- Author
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Lazari, D, primary, Gabrieli, C, additional, Papi, R, additional, Tsoleridis, K, additional, and Kyriakidis, D, additional
- Published
- 2008
- Full Text
- View/download PDF
24. A multi-parametric protocol to study exercise intolerance in McArdle's disease
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Ricci, G., Bertolucci, F., Logerfo, A., Simoncini, C., Papi, R., FERDINANDO FRANZONI, Osso, G., Servadio, A., Masoni, M. C., and Siciliano, G.
- Subjects
Adult ,Male ,McArdle disease ,muscle exercise ,myophosphorylase deficiency ,Monitoring, Ambulatory ,Original Articles ,Middle Aged ,Oxidative Stress ,Exercise Test ,Lactates ,Glycogen Storage Disease Type V ,Humans ,Female ,Energy Metabolism - Abstract
McArdle's disease is the most common metabolic myopathy of muscle carbohydrate metabolism, due to deficiency of myophosphorylase and alteration of glycogen breakdown in muscle. The clinical manifestations usually begin in young adulthood, with exercise intolerance, exercise-induced muscle cramps, pain and recurrent episodes of myoglobinuria. Many patients experience the second wind phenomenon, characterized by an improved tolerance for aerobic exercise approximately after eight minutes of motor activity, secondary to the increased availability of blood glucose and free fatty acids associated to an enhanced glucose uptake by muscle cells. In this study, we aimed to test a multi-parametric protocol in order to detect the impairment of muscular metabolism and motor performance in patients with McArdle's disease. We enrolled 5 patients and 5 age-matched healthy subjects, that were evaluated by: (01) monitoring of physical activity with an electronic armband; (02) testing of cardiopulmonary, metabolic and respiratory responses to exercise with a cardiopulmonary exercise test and analyzing muscle fatigue during exercise test by surface electromyography (04) evaluating blood lactate and oxidative stress biomarkers at rest and during exercise. The patients were tested at baseline and after three days of carbohydrate-rich diet integrated with tricarboxylic acid cycle intermediate and creatine. The multiparametric protocol proved to be useful to detect the oxidative capacity impairment and the second wind phenomenon of patients. We did not observe any significant differences of muscle metabolic response during the exercise test after three days of carbohydrate-rich diet.
25. Polyhydroxyalkanoates: New browsing the PHA biosynthesis insights in native and recombinant strains
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Giourieva, V. S., Papi, R. M., and Anastasia PANTAZAKI
26. P-3Exercise intolerance in Mc Ardle Disease:functional and metabolic evaluation
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Bertolucci F, Ricci G, Papi R, Franzoni F, Galetta F, Bigalli G, Mc, Zecca, Gennaro Tartarisco, Masoni C, Lo Gerfo A, and Siciliano G
27. Polyhydroxyalkanoates: An ideal polymeric material in food packaging
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Halevas, E. G., Andriotis, E. G., Papi, R. M., and Anastasia PANTAZAKI
28. Experimental campaign on a servo-actuated pantograph
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Allotta, B., primary, Papi, R., additional, Pugi, L., additional, Toni, P., additional, and Violi, A.G., additional
- Full Text
- View/download PDF
29. Encapsulated Escherichia coli in alginate beads capable of secreting a heterologous pectin lyase
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Trikka Fotini A, Chaitidou Sotiria A, Papi Rigini M, and Kyriakidis Dimitrios A
- Subjects
Microbiology ,QR1-502 - Abstract
Abstract Background Production of heterologous proteins in the E. coli periplasm, or into the extracellular fluid has many advantages; therefore naturally occurring signal peptides are selected for proteins translocation. The aim of this study was the production in high yields of a recombinant pectin lyase that is efficiently secreted and the encapsulation of transformed E. coli cells for pectin degradation in a biotechnological process. Results The nucleotide sequence of Bacillus subtilis α-amylase's signal peptide was fused to the N-terminal of an heterologously expressed pectin lyase in E. coli BL21 [DE3]. Thus pectin lyase secretion was achieved into the extracellular growth medium. E. coli cells harboring the recombinant plasmid heterologously express pectin lyase to around 22% of the total cellular proteins, as it was estimated by SDS-PAGE and image analysis. IPTG induces the heterologously expressed enzyme, which is initially distributed extracellularly (7 hour) and later on at the periplasmic (9 hours) or cytosolic fraction (20 hours). No pectin lyase activity was found in the membranes fraction and in the inclusion bodies. Encapsulation of the recombinant strains of E. coli in alginate or alginate/silica beads 1:5 showed that pectin lyase could degrade effectively its substrate, for at least ten operational cycles. Conclusion Secretion of an heterologously overexpressed pectin lyase in E. coli BL21 [DE3] was achieved in this study. For this purpose the signal peptide of α-amylase from B. subtilis was fused to the N-terminal domain of pectin lyase. Encapsulated E. coli BL21 [DE3] cells harboring pET29c/exPNL were used successfully for pectin degradation up to ten operational cycles indicating that under special conditions this might have biotechnological implementations.
- Published
- 2005
- Full Text
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30. Experimental campaign on a servo-actuated pantograph.
- Author
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Allotta, B., Papi, R., Pugi, L., Toni, P., and Violi, A.G.
- Published
- 2001
- Full Text
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31. Improntas de esterillas en cerámicas del Bronce Final de la Peña Negra (Crevillente, Alicante) (Campañas de 1983 y 1984)
- Author
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Papí Rodes, Concepción
- Subjects
Prehistoric archaeology ,GN700-890 ,Archaeology ,CC1-960 - Abstract
En algunos ejemplares de bases de cerámicas a mano del yacimiento del Bronce Final de La Peña Negra se observan improntas de esterillas, principalmente de estructura circular, aunque también existe algún ejemplar de tipo rectangular. El presente trabajo atiende a la descripción de este tipo de piezas y sus improntas y analiza la funcionalidad de estas esterillas, englobándolas dentro del marco de los restos de labores de cestería y esparto a lo largo de la Prehistoria más reciente.
- Published
- 1994
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32. Epigallocatechin-3-gallate inhibits doxorubicin-induced inflammation on human ovarian tissue
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Marie-Pierre Piccinni, Maria Macciocca, Giacomo Caprara, Roberto Paradisi, Alessio Papi, Rossella Vicenti, Renato Seracchioli, P Terzano, Raffaella Fabbri, and R Fabbri , M Macciocca , R Vicenti , G Caprara , M P Piccinni , R Paradisi , P Terzano , A Papi , R Seracchioli
- Subjects
0301 basic medicine ,Adult ,MMP2 ,Anthracycline ,Cell Survival ,medicine.medical_treatment ,Biophysics ,Anti-Inflammatory Agents ,Inflammation ,Protective Agents ,Biochemistry ,doxorubicin ,Catechin ,03 medical and health sciences ,0302 clinical medicine ,Western blot ,medicine ,polycyclic compounds ,Humans ,Doxorubicin ,Molecular Biology ,Research Articles ,Chemotherapy ,TUNEL assay ,Antibiotics, Antineoplastic ,medicine.diagnostic_test ,business.industry ,Ovary ,human ovarian tissue ,Cell Biology ,030104 developmental biology ,inflammation ,030220 oncology & carcinogenesis ,Cancer research ,Metalloproteases ,Cytokines ,Tumor necrosis factor alpha ,Female ,epigallocatechin-3-gallate ,medicine.symptom ,business ,medicine.drug ,Research Article - Abstract
Chemotherapy protocol can destroy the reproductive potential of young cancer patients. Doxorubicin (DOX) is a potent anthracycline commonly used in the treatment of numerous malignancies. The purpose of the study was to evaluate the ovarian toxicity of DOX via inflammation and the possible protective effect of the green tea polyphenol epigallocatechin-3-gallate (EGCG). Ovarian tissue of three patients was cultured with 1 µg/ml DOX and/or 10 µg/ml EGCG for 24 and 48 h. Levels of inflammatory factors were determined by quantitative Real-Time PCR, western blot, zimography, and multiplex bead-based immunoassay. Morphological evaluation, damaged follicle count and TUNEL assay were also performed. DOX influenced inflammatory responses by inducing a significant increase in the expression of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and cyclooxigenase-2 (COX-2), of inflammatory interleukins (IL), such as interleukin-6 (IL-6) and interleukin-8 (IL-8), and the inflammatory proteins mediators metalloproteinase-2 and metalloproteinase-9 (MMP2 and MMP9). IL-8 secretion in the culture supernatants and MMP9 activity also significantly raised after DOX treatment. Moreover, a histological evaluation of the ovarian tissue showed morphological damage to follicles and stroma after DOX exposure. EGCG significantly reduced DOX-induced inflammatory responses and improved the preservation of follicles. DOX-induced inflammation could be responsible for the ovarian function impairment of chemotherapy. EGCG could have a protective role in reducing DOX-mediated inflammatory responses in human ovarian tissue.
- Published
- 2019
33. Ricerche su una specie di interesse etnobotanico e biotecnologico: la Santolina etrusca
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Bacchetta, L., Letardi, A., Salvatori, B., Catarci, S., Fabretti, M., D’Auria, F. D., Forti, G., Forti, G., Tellini Florenzano, G., Calvario, E., Battisti, C., Papi, R., Bacchetta, L., Letardi, A., Salvatori, B., Catarci, S., Fabretti, M., and D’Auria, F. D.
- Subjects
santolina ,etnobotanica ,usi biotecnologici - Published
- 2012
34. Amine-substituted heterocyclic thioamide Cu(I) and Ag(I) complexes as effective anticancer and antibacterial agents targeting the periplasm of E. coli bacteria.
- Author
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Varna D, Geromichalos GD, Dalezis P, Hatzidimitriou AG, Psomas G, Zachariadis G, Psatha K, Aivaliotis M, Papi R, Trafalis D, and Angaridis PA
- Subjects
- Humans, Molecular Structure, Structure-Activity Relationship, Amines chemistry, Amines pharmacology, Amines chemical synthesis, Cell Proliferation drug effects, Dose-Response Relationship, Drug, Cell Line, Tumor, Heterocyclic Compounds chemistry, Heterocyclic Compounds pharmacology, Heterocyclic Compounds chemical synthesis, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents chemical synthesis, Antineoplastic Agents pharmacology, Antineoplastic Agents chemistry, Antineoplastic Agents chemical synthesis, Escherichia coli drug effects, Copper chemistry, Copper pharmacology, Thioamides chemistry, Thioamides pharmacology, Thioamides chemical synthesis, Microbial Sensitivity Tests, Coordination Complexes pharmacology, Coordination Complexes chemistry, Coordination Complexes chemical synthesis, Silver chemistry, Silver pharmacology, Drug Screening Assays, Antitumor
- Abstract
Metal complexes showing dual activity against cancer and bacterial infections are currently the focus of significant interest for their potential in treating life-threatening diseases. Aiming to investigate the impact of ligand substituents on these bioactivity properties of Group 11 d
10 metal complexes, we herein present a series of mononuclear Cu(I) and Ag(I) complexes featuring the bis-NH2 -substituted heterocyclic thioamide dap2SH (=4,6-diaminopyrimidine-2-thione), namely [AgCl(dap2SH)(PPh3 )2 ] (1), [CuBr(dap2SH)(PPh3 )2 ] (2), [CuBr(dap2SH)(xantphos)] (3), [Ag(dap2S)(xantphos)] (4), and [Cu(dap2S)(xantphos)] (5) (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene). Complexes were characterized by means of different physicochemical methods (i.e., single crystal X-ray diffraction as well as FTIR, NMR, UV-Vis and fluorescence spectroscopy), and studied in-vitro for their antibacterial and anticancer activity against a variety of bacterial strains and cancer cell lines. Complexes 1-3 effectively inhibited both Gram (+) and Gram (-) bacterial growth, while cellular uptake studies for the most potent complex 1 against E. coli bacteria revealed the accumulation of Ag(I) ions in the periplasm of the bacteria. A high anti-proliferative effect was observed for 1 and 5 against A549, MCF7 and PC3 cancer cell lines, with 1 being capable of inducing apoptosis in A549 cells, as suggested by flow cytometry analysis. DNA interaction studies revealed the capacity of 1 to intercalate between base-pairs of CT DNA. All complexes had a moderate-to-high capacity to scavenge free radicals preventing oxidative stress. Molecular docking calculations, in combination with the experimentally obtained data, provided insights for potential mechanisms of the bioactivity of the complexes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)- Published
- 2024
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35. Assessing the role of drought in dust storm formation in the Tigris and Euphrates basin.
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Darvishi Boloorani A, Soleimani M, Papi R, Nasiri N, Neysani Samany N, Mirzaei S, and Al-Hemoud A
- Abstract
Drought is a common meteorological phenomenon and one of the world's most costly natural hazards. A large part of the Tigris and Euphrates basin (TEB) is located in the arid and semi-arid regions of western Asia and suffers from drought. Drought has many destructive effects on the environment and human societies, among which the formation of dust storms, is a major global challenge. This study aims to figure out the role of different types of drought on dust storm formation in the TEB. Standardized precipitation index (SPI), Tasseled Cap greenness index, and surface water area changes based on time series of satellite remote sensing data were considered as proxies to investigate meteorological, agricultural, and hydrological droughts, respectively. Our results show that the continuation of the 5-month and 27-month meteorological droughts are followed by agricultural and hydrological droughts, respectively. In recent decades, the TEB has experienced two prominent drought periods in 2008-2012 and 2021-2022, resulting in a 214 % and 200 % increase in dust events, respectively, compared to the 23-year (2000-2022) average. Overall, 84 %, 10 %, and 6 % of the TEB dust events can be attributed to meteorological, agricultural, and hydrological droughts, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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36. N-heterocyclic-carbene vs diphosphine auxiliary ligands in thioamidato Cu(I) and Ag(I) complexes towards the development of potent and dual-activity antibacterial and apoptosis-inducing anticancer agents.
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Varna D, Geromichalos G, Gioftsidou DK, Tzimopoulos D, Hatzidimitriou AG, Dalezis P, Papi R, Trafalis D, and Angaridis PA
- Subjects
- Humans, Ligands, Molecular Docking Simulation, Anti-Bacterial Agents pharmacology, Methane pharmacology, Bacteria, Apoptosis, Antineoplastic Agents pharmacology, Coordination Complexes pharmacology, Heterocyclic Compounds pharmacology
- Abstract
Group 11 metal complexes exhibit promising antibacterial and anticancer properties which can be further enhanced by appropriate ligands. Herein, a series of mononuclear thioamidato Cu(I) and Ag(I) complexes bearing either a diphosphine (P^P) or a N-heterocyclic carbene (NHC) auxiliary ligand (L) was synthesized, and the impact of the co-ligand L on the in vitro antibacterial and anticancer properties of their complexes was assessed. All complexes effectively inhibited the growth of various bacterial strains, with the NHC-Cu(I) complex found to be particularly effective against the Gram (+) bacteria (IC
50 = 1-4 μg mL-1 ). Cytotoxicity studies against various human cancer cells revealed their high anticancer potency and the superior activity of the NHC-Ag(I) complex (IC50 = 0.95-4.5 μΜ). Flow cytometric analysis on lung and breast cancer cells treated with the NHC-Ag(I) complex suggested an apoptotic cell-death pathway; molecular docking calculations provided mechanistic insights, proving the capacity of the complex to bind on apoptosis-regulating proteins and affect their functionalities., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2024
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37. Study of Biological Behavior and Antimicrobial Properties of Cerium Oxide Nanoparticles.
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Chatzimentor I, Tsamesidis I, Ioannou ME, Pouroutzidou GK, Beketova A, Giourieva V, Papi R, and Kontonasaki E
- Abstract
(1) Background: An element that has gained much attention in industrial and biomedical fields is Cerium (Ce). CeO
2 nanoparticles have been proven to be promising regarding their different biomedical applications for the control of infection and inflammation. The aim of the present study was to investigate the biological properties and antimicrobial behavior of cerium oxide (CeO2 ) nanoparticles (NPs). (2) Methods: The investigation of the NPs' biocompatibility with human periodontal ligament cells (hPDLCs) was evaluated via the MTT assay. Measurement of alkaline phosphatase (ALP) levels and alizarine red staining (ARS) were used as markers in the investigation of CeO2 NPs' capacity to induce the osteogenic differentiation of hPDLCs. Induced inflammatory stress conditions were applied to hPDLCs with H2 O2 to estimate the influence of CeO2 NPs on the viability of cells under these conditions, as well as to reveal any ROS scavenging properties. Total antioxidant capacity (TAC) of cell lysates with NPs was also investigated. Finally, the macro broth dilution method was the method of choice for checking the antibacterial capacity of CeO2 against the anaerobic pathogens Porphyromonas gingivalis and Prevotella intermedia . (3) Results: Cell viability assay indicated that hPDLCs increase their proliferation rate in a time-dependent manner in the presence of CeO2 NPs. ALP and ARS measurements showed that CeO2 NPs can promote the osteogenic differentiation of hPDLCs. In addition, the MTT assay and ROS determination demonstrated some interesting results concerning the viability of cells under oxidative stress conditions and, respectively, the capability of NPs to decrease free radical levels over the course of time. Antimicrobial toxicity was observed mainly against P. gingivalis . (4) Conclusions: CeO2 NPs could provide an excellent choice for use in clinical practices as they could prohibit bacterial proliferation and control inflammatory conditions.- Published
- 2023
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38. A Low-Power High Input Range PPG Readout Amplifier with a Current Buffer Input .
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Mazandarani MS, Gagnon-Turcotte G, Papi R, and Gosselin B
- Subjects
- Equipment Design, Heart Rate, Amplifiers, Electronic, Photoplethysmography, Signal Processing, Computer-Assisted
- Abstract
This paper presents ultra-low power photoplethysmography (PPG) readout circuits. The proposed system architecture uses a current buffer between the photodiode (PD) and the transimpedance amplifier (TIA) to isolate the large parasitic capacitance of the PD leading to improves the power consumption of the TIA. A class AB topology is exploited at the output of the amplifier, which allows for increased drive capability without the use of auxiliary circuits. The maximum input current range of the TIA is 160 µA, so the large DC current of the input signal does not saturate the circuit. In the LED driver circuit, by varying the duty cycle of a pulse wave modulation (PWM) signal, the ON and OFF times of the circuits. The amplifier and LED driver are manufactured in the 130 nm TSMC CMOS process. The power consumption of the circuits with a duty cycle of 1% is 3.28 µW (at VDD = 1.2V).Clinical Relevance- Vital signs are becoming a very important research topic due to the recent prevalence of COVID-19 and other respiratory diseases. This research aims to develop and interface circuits to monitor vital signs including blood pressure, heart rate, and respiratory rate to study respiratory disease, drug safety, and efficacy.
- Published
- 2023
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39. Inhibition of Cancer Cell Proliferation and Bacterial Growth by Silver(I) Complexes Bearing a CH 3 -Substituted Thiadiazole-Based Thioamide.
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Varna D, Geromichalou E, Karlioti G, Papi R, Dalezis P, Hatzidimitriou AG, Psomas G, Choli-Papadopoulou T, Trafalis DT, and Angaridis PA
- Subjects
- Humans, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Cell Proliferation, Molecular Docking Simulation, Silver chemistry, Thioamides pharmacology, Antineoplastic Agents pharmacology, Antineoplastic Agents chemistry, Coordination Complexes chemistry, Neoplasms
- Abstract
Ag(I) coordination compounds have recently attracted much attention as antiproliferative and antibacterial agents against a wide range of cancer cell lines and pathogens. The bioactivity potential of these complexes depends on their structural characteristics and the nature of their ligands. Herein, we present a series of four Ag(I) coordination compounds bearing as ligands the CH
3 -substituted thiadiazole-based thioamide 5-methyl-1,3,4-thiadiazole-2-thiol (mtdztH) and phosphines, i.e., [AgCl(mtdztH)(PPh3 )2 ] ( 1 ), [Ag(mtdzt)(PPh3 )3 ] ( 2 ), [AgCl(mtdztH)(xantphos)] ( 3 ), and [AgmtdztH)(dppe)(NO3 )]n ( 4 ), where xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and dppe = 1,2-bis(diphenylphosphino)ethane, and the assessment of their in vitro antibacterial and anti-cancer efficiency. Among them, diphosphine-containing compounds 3 and 4 were found to exhibit broad-spectrum antibacterial activity characteristics against both Gram-(+) and Gram-(-) bacterial strains, showing high in vitro bioactivity with IC50 values as low as 4.6 μΜ. In vitro cytotoxicity studies against human ovarian, pancreatic, lung, and prostate cancer cell lines revealed the strong cytotoxic potential of 2 and 4 , with IC50 values in the range of 3.1-24.0 μΜ, while 3 and 4 maintained the normal fibroblast cells' viability at relatively higher levels. Assessment of these results, in combination with those obtained for analogous Ag(I) complexes bearing similar heterocyclic thioamides, suggest the pivotal role of the substituent groups of the thioamide heterocyclic ring in the antibacterial and anti-cancer efficacy of the respective Ag(I) complexes. Compounds 1 - 4 exhibited moderate in vitro antioxidant capacity for free radicals scavenging, as well as reasonably strong ability to interact with calf-thymus DNA, suggesting the likely implication of these properties in their bioactivity mechanisms. Complementary insights into the possible mechanism of their anti-cancer activity were provided by molecular docking calculations, exploring their ability to bind to the overexpressed fibroblast growth factor receptor 1 (FGFR1), affecting cancer cells' functionalities.- Published
- 2023
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40. Silver(I) complexes bearing heterocyclic thioamide ligands with NH 2 and CF 3 substituents: effect of ligand group substitution on antibacterial and anticancer properties.
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Varna D, Geromichalou E, Hatzidimitriou AG, Papi R, Psomas G, Dalezis P, Aslanidis P, Choli-Papadopoulou T, Trafalis DT, and Angaridis PA
- Subjects
- Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Escherichia coli, Ligands, Molecular Docking Simulation, Silver chemistry, Silver pharmacology, Staphylococcus aureus, Thioamides pharmacology, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Coordination Complexes chemistry, Coordination Complexes pharmacology
- Abstract
In recent years, there has been an increasing interest in the study of Ag(I) coordination compounds as potent antibacterial and anticancer agents. Herein, a series of Ag(I) complexes bearing phosphines and heterocyclic thioamide ligands with highly electronegative NH
2 - and CF3 -group substituents, i.e. [AgCl(atdztH)(xantphos)] (1), [Ag(μ-atdztH)(DPEphos)]2 (NO3 )2 (2), [Ag(atdzt)(PPh3 )3 ] (3), [Ag(μ-atdzt)(DPEphos)]2 (4), and [Ag(μ-mtft)(DPEphos)]2 (5), where atdztH = 5-amino-1,3,4-thiadiazole-2-thiol, mtftH = 4-methyl-5-(trifluoromethyl)-1,2,4-triazol-3-thiol, xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, and DPEphos = bis(2-diphenylphosphino-phenyl)ether, were synthesized, and their in vitro antibacterial and anticancer properties were evaluated. Complexes 1-4 bearing the NH2 -substituted thioamide exhibited moderate-to-high activity against S. aureus , B. subtilis , B. cereus and E. coli bacterial strains. A high antiproliferative activity was also observed for 1-3 against SKOV-3, Hup-T3, DMS114 and PC3 cancer cell lines (IC50 = 4.0-11.7 μM), as well as some degree of selectivity against MRC-5 normal cells. Interestingly, 5 bearing the CF3 -substituted thioamide is completely inactive in all bioactivity studies. Binding of 1-3 to drug-carrier proteins BSA and HSA is reasonably strong for their uptake and subsequent release to possible target sites. The three complexes show a significant in vitro antioxidant ability for scavenging free radicals, suggesting likely implication of this property in the mechanism of their bioactivity, but a low potential to destroy the double-strand structure of CT-DNA by intercalation. Complementary insights into possible bioactivity mechanisms were provided by molecular docking calculations, exploring the ability of complexes to bind to bacterial DNA gyrase, and to the overexpressed in the aforementioned cancer cells Fibroblast Growth Factor Receptor 1, affecting their functionalities.- Published
- 2022
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41. Pegylated-polycaprolactone nano-sized drug delivery platforms loaded with biocompatible silver(i) complexes for anticancer therapeutics.
- Author
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Varna D, Christodoulou E, Gounari E, Apostolidou CP, Landrou G, Papi R, Koliakos G, Coutsolelos AG, Bikiaris DN, and Angaridis PA
- Abstract
Cytotoxic potential of Ag(i) coordination compounds against cancer cells is widely recognized, but their frequently low water solubility and potential adverse interactions of Ag(i) ions in biological media require their incorporation into suitable platforms to ensure effective transport and delivery at target sites. Herein, we developed and evaluated the in vitro cytotoxic activity of a biodegradable copolymer-based nano-sized drug delivery system for three cytotoxically active and lipophillic Ag(i) compounds. In particular, polymer-based nanoparticles of the newly synthesized amphiphilic methoxy-poly(ethylene glycol)-poly(caprolactone) ( mPEG-PCL ) copolymer were prepared as carriers for [Ag(dmp2SH)(PPh
3 )2 ]NO3 (1), [Ag(dmp2SH)(xantphos)]NO3 (2) and [Ag(dmp2S)(xantphos)] (3) (dmP2SH = 4,6-dimethylpyrimidine-2-thiol, xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) which exhibit high cytotoxicity against HeLa cancer cells, while they maintain low toxicity against HDFa normal cells. Taking advantage of the favorable donor-acceptor Lewis acid-base and electrostatic interactions between functional groups of 1-3 and mPEG-PCL copolymer, the formation of [X]@mPEG-PCL (X = 1,2,3) nanoparticles with nearly spherical shape was achieved. Satisfactory loading capacities and encapsulation efficiencies were obtained (13-15% and 80-88%, respectively). Differences in their mean size diameters were observed, revealing a dependence on the individual structural characteristics of the Ag(i) compounds. In vitro release profiles of the nanoparticles showed an initial burst stage, followed by a prolonged release stage extending over 15 days, with their release rates being determined by the mean size of the nanoparticles, as well as the type and crystallinity of the encapsulated Ag(i) compounds. In vitro cytotoxicity studies revealed an increased cytotoxic activity of compounds 1-3 after their encapsulation in mPEG-PCL copolymer against HeLa cells, with the actual concentrations of the loaded compounds responsible for the inhibition of cell viability being reduced by 8 times compared to the compounds in free form. Therefore, the current drug delivery system improves the pharmacokinetic properties of the three cytotoxic and biocompatible Ag(i) compounds, and may be beneficial for future in vivo anticancer treatment., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2022
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42. Biocompatible silver(I) complexes with heterocyclic thioamide ligands for selective killing of cancer cells and high antimicrobial activity - A combined in vitro and in silico study.
- Author
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Varna D, Geromichalou E, Papachristou E, Papi R, Hatzidimitriou AG, Panteris E, Psomas G, Geromichalos GD, Aslanidis P, Choli-Papadopoulou T, and Angaridis PA
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Infective Agents chemistry, Antineoplastic Agents pharmacology, Antioxidants pharmacology, Bacteria drug effects, Cyclin-Dependent Kinase 6 metabolism, DNA metabolism, DNA Gyrase metabolism, HeLa Cells, Humans, Ligands, MCF-7 Cells, Microbial Sensitivity Tests methods, Models, Molecular, Molecular Docking Simulation methods, Phosphines chemistry, Silver pharmacology, Thioamides pharmacology, Xanthenes chemistry, Anti-Infective Agents pharmacology, Coordination Complexes chemistry, Silver chemistry, Thioamides chemistry
- Abstract
A series of heteroleptic Ag(I) complexes bearing 4,6-dimethyl-2-pyrimidinethiol (dmp2SH), i.e., [AgCl(dmp2SH)(PPh
3 )2 ] (1), [Ag(dmp2SH)(PPh3 )2 ]NO3 (2), [Ag(dmp2SΗ)(xantphos)]NO3 (3), [Ag(μ-dmp2S)(PPh3 )]2 (4), [Ag(dmp2S)(xantphos)] (5), [Ag(μ-dmp2S)(DPEphos)]2 (6) (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and DPEPhos = bis[(2-diphenylphosphino)phenyl]ether) were synthesized. The complexes display systematic variation of particular structural characteristics which were proved to have a significant impact on their in vitro cytotoxicity and antimicrobial properties. A moderate-to-high potential for bacteria growth inhibition was observed for all complexes, with 2, 3 and 5 being particularly effective against Gram-(+) bacteria (IC50 = 1.6-4.5 μM). The three complexes exhibit high in vitro cytotoxicity against HeLa and MCF-7 cancer cells (IC50 = 0.32-3.00 μΜ), suggesting the importance of coordination unsaturation and cationic charge for effective bioactivity. A very low cytotoxicity against HDFa normal cells was observed, revealing a high degree of selectivity (selectivity index ~10) and, hence, biocompatibility. Fluorescence microscopy using 2 showed effective targeting on the membrane of the HeLa cancer cells, subsequently inducing cell death. Binding of the complexes to serum albumin proteins is reasonably strong for potential uptake and subsequent release to target sites. A moderate in vitro antioxidant capacity for free radicals scavenging was observed and a low potential to destroy the double-strand structure of calf-thymus DNA by intercalation, suggesting likely implication of these properties in the bioactivity mechanisms of these complexes. Further insight into possible mechanisms of bioactivity was obtained by molecular modeling calculations, by exploring their ability to act as potential inhibitors of DNA-gyrase, human estrogen receptor alpha, human cyclin-dependent kinase 6, and human papillomavirus E6 oncoprotein., (Copyright © 2021. Published by Elsevier Inc.)- Published
- 2022
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43. Characterization of Oregano Essential Oil ( Origanum vulgare L. subsp. hirtum ) Particles Produced by the Novel Nano Spray Drying Technique.
- Author
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Plati F, Papi R, and Paraskevopoulou A
- Abstract
Oregano essential oil (OEO), due to its wide variety of biological activities, could be a "green" alternative to chemical preservatives. On the other hand, the difficulties in its use or storage have turned researchers' interest in encapsulation strategies as a way to face stability and handling issues. Fabrication of OEO-loaded particles, using nano spray drying technique (NSD) and whey protein isolate-maltodextrin mixtures (1:1, 1:3) as wall materials appears to be a novel and promising strategy. The obtained particles were characterized in terms of volatile composition, encapsulation efficiency, and physicochemical, molecular, morphological, and antibacterial properties. The results confirmed that encapsulation of OEO using NSD achieved high levels of powder recovery (>77%) and encapsulation efficiency (>98%) while assisting in the retention of the main bioactive compounds. The partial replacement of WPI by MD significantly affected particles' physical properties. FTIR analyses revealed the possible structural stabilization of core and wall materials, while SEM verified the very fine size and spherical shape. Finally, antibacterial studies demonstrated their activity against Escherichia coli and Staphylococcus aureus , which is much stronger in comparison with that of pure OEO, proving the positive effect of NSD and particles' potential in future food applications.
- Published
- 2021
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44. De Novo Synthesis of Elastin-like Polypeptides (ELPs): An Applied Overview on the Current Experimental Techniques.
- Author
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Riziotis IG, Lamprou P, Papachristou E, Mantsou A, Karolidis G, Papi R, and Choli-Papadopoulou T
- Subjects
- Animals, Biopolymers, Drug Delivery Systems, Humans, Peptides genetics, Elastin genetics, Escherichia coli genetics
- Abstract
Elastin-like polypeptides (ELPs) are protein-based biopolymers genetically produced from polypeptides composed of a repeating pentapeptide sequence V-P-G-X-G. The inherent properties of recombinant ELPs, such as smart nature, controlled sequence complexity, physicochemical properties, and biocompatibility, make these polymers suitable for use in nanobiotechnological applications, as biofunctionalized scaffolds for tissue-engineering purposes and drug delivery. In this work, we report the design and synthesis of two elastomeric self-assembling polypeptides (ELPs) that mimic the endogenous human tropoelastin. Using molecular biology techniques, two artificial genes that encode two ELP concatemers of approximate molecular mass 60 kDa, one of them carrying biotin-binding peptide motifs, were constructed. These motifs could facilitate biofunctionalization of the ELPs through tethering biotinylated factors, such as growth factors. The ELPs were heterologously overexpressed in E. coli and subsequently purified in two steps: a nonchromatographic technique by organic solvent extraction, followed by nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography. The characterization of the biochemical properties and biocompatibility of ELPs was also performed in this study. The ELP carrying the biotin-binding motifs was tested for its capability to bind biotin, and indeed, it was observed that it can bind biotinylated proteins specifically. Additionally, results concerning the cytotoxicity of the ELPs exhibited excellent compatibility of the ELPs with mammalian cells in vitro. We anticipate that these ELPs can be used as components of a scaffold that mimics the e xtra c ellular m atrix (ECM) for the regeneration of endogenously highly elastic tissues.
- Published
- 2021
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45. Biopharmaceutics 4.0, Advanced Pre-Clinical Development of mRNA-Encoded Monoclonal Antibodies to Immunosuppressed Murine Models.
- Author
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Ouranidis A, Choli-Papadopoulou T, Papachristou ET, Papi R, and Kostomitsopoulos N
- Abstract
Administration of mRNA against SARS-CoV-2 has demonstrated sufficient efficacy, tolerability and clinical potential to disrupt the vaccination field. A multiple-arm, cohort randomized, mixed blind, placebo-controlled study was designed to investigate the in vivo expression of mRNA antibodies to immunosuppressed murine models to conduct efficacy, safety and bioavailability evaluation. Enabling 4.0 tools we reduced animal sacrifice, while interventions were designed compliant to HARRP and SPIRIT engagement: (a) Randomization, blinding; (b) pharmaceutical grade formulation, monitoring; (c) biochemical and histological analysis; and (d) theoretic, statistical analysis. Risk assessment molded the study orientations, according to the ARRIVE guidelines. The primary target of this protocol is the validation of the research hypothesis that autologous translation of Trastuzumab by in vitro transcribed mRNA-encoded antibodies to immunosuppressed animal models, is non-inferior to classical treatments. The secondary target is the comparative pharmacokinetic assessment of the novel scheme, between immunodeficient and healthy subjects. Herein, the debut clinical protocol, investigating the pharmacokinetic/pharmacodynamic impact of mRNA vaccination to immunodeficient organisms. Our design, contributes novel methodology to guide the preclinical development of RNA antibody modalities by resolving efficacy, tolerability and dose regime adjustment for special populations that are incapable of humoral defense.
- Published
- 2021
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46. Specific amino acids from the broad C-terminal region of BMP-2 are crucial for osteogenesis.
- Author
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Karoulias SZ, Pitou M, Papi R, Lamprou P, and Choli-Papadopoulou T
- Abstract
The shortest functional domains of growth factor B one M orphogenetic P rotein 2 (BMP-2) that are dynamical implicated in osteogenesis have been investigated and well characterized. In particular, the broad C-terminal region expanding from Val63 to Arg114 as well as its shorter sequence 86-AISMLYLDEN-95 exhibited the highest osteogenic ability for regeneration and reconstruction of bone tissue. In addition, the amino acids Ser88 and Leu90 have been identified as crucial for receptor binding and osteogenic efficacy. Furthermore, the above-mentioned domains in contrary to full length BMP-2 protein signal mainly through the Smad pathway as it is evidenced by phosphorylation decrease of Extracellular-signal-Regulated Kinase (ERK1/2). Taking together, our results are significant for clinical applications regarding the generation of biomaterials and healing of orthopedic fractures., Competing Interests: None., (© 2021 The Author(s).)
- Published
- 2021
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47. Graphene-Wrapped Copper Nanoparticles: An Antimicrobial and Biocompatible Nanomaterial with Valuable Properties for Medical Uses.
- Author
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Vasilopoulos V, Pitou M, Fekas I, Papi R, Ouranidis A, Pavlidou E, Patsalas P, and Choli-Papadopoulou Τ
- Abstract
The great demand for antibacterial, biocompatible, and easily manufactured nanostructures has led to the design and development of graphene-wrapped copper nanoparticles (CuNPs) supported on Si wafers. In this study, we investigated the antibacterial properties of graphene/CuNPs nanostructures against Gram-positive and Gram-negative bacteria. Additional experiments regarding graphene/CuNPs nanostructures behavior against mouse fibroblast cell line L929 indicated their biocompatibility and consequently render them as model biomaterials for medical uses. Biofunctionalization of graphene/CuNPs nanostructures with a high-molecular-weight protein (green fluorescent protein), which retains its functionality after a "tight binding" on the nanostructure's surface, opens the way for attaching and other proteins, or biomolecules of great biological interest, to prepare novel biomaterials., Competing Interests: The authors declare no competing financial interest.
- Published
- 2020
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48. Synthesis, physicochemical characterization and biological properties of two novel Cu(II) complexes based on natural products curcumin and quercetin.
- Author
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Halevas E, Pekou A, Papi R, Mavroidi B, Hatzidimitriou AG, Zahariou G, Litsardakis G, Sagnou M, Pelecanou M, and Pantazaki AA
- Subjects
- Coordination Complexes chemical synthesis, Coordination Complexes chemistry, Coordination Complexes pharmacology, Copper chemistry, Copper pharmacology, Curcumin chemistry, Curcumin pharmacology, DNA chemistry, Plasmids chemistry, Quercetin chemistry, Quercetin pharmacology, Saccharomyces cerevisiae growth & development
- Abstract
Curcumin and quercetin are two of the most prominent natural polyphenols with a diverse spectrum of beneficial properties, including antioxidant, anti-inflammatory, chemopreventive and chemotherapeutic activity. The complexation of these natural products with bioactive transition metal ions can lead to the generation of novel metallodrugs with enhanced biochemical and pharmacological activities. Within this framework, the synthesis and detailed structural and physicochemical characterization of two novel complex assemblies of Cu(II) with curcumin and quercetin and the ancillary aromatic chelator 2,2'-bipyridine is presented. The two complexes represent the only crystallographically characterized structures with Cu(II) as the central metal ion and curcumin or quercetin as the ligands. The new complexes were biologically evaluated in vitro for their antioxidant potential, both exhibiting strong scavenging activity in the 2,2-diphenyl-1-picrylhydrazyl assay, and their plasmid DNA binding/cleavage properties. Both complexes appear to be non-toxic in the eukaryotic experimental model Saccharomyces cerevisiae and merit further investigation of their pharmacological profile., Competing Interests: Declaration of competing interest No conflict of interest was declared by the authors., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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49. Assessment of cytotoxicity and antibacterial effects of silver nanoparticle-doped titanium alloy surfaces.
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Kirmanidou Y, Sidira M, Bakopoulou A, Tsouknidas A, Prymak O, Papi R, Choli-Papadopoulou T, Epple M, Michailidis N, Koidis P, and Michalakis K
- Subjects
- Alloys, Anti-Bacterial Agents, Silver, Metal Nanoparticles, Titanium
- Abstract
Objectives: This study aimed to develop silver nanoparticle (AgNP)-doped Ti
6 Al4 V alloy surfaces and investigate their antibacterial properties against representative periopathogens and potential cytotoxicity on osteoblastic cells., Methods: AgNPs of different size distributions (5 and 30nm) were incorporated onto the Ti6 Al4 V surfaces by electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations (100, 200 and 300ppm). The time-course silver release from the specimen surfaces to cell culture media was assessed by Atomic Absorption Spectroscopy (AAS). Cell attachment, viability and proliferation were investigated by SEM, live/dead staining MTT and BrdU assays. The antibacterial effects were assessed against P. gingivalis and P. intermedia by serial dilution spotting assays., Results: A time- and concentration-dependent silver release from the experimental surfaces was observed. Overall, cell viability and attachment on the AgNP-doped surfaces, suggested adequate cytocompatibility at all concentrations. A transient cytotoxic effect was detected at 24h for the 5nm-sized groups that fully recovered at later time-points, while no cytotoxicity was observed for the 30nm-sized groups. A statistically significant, concentration-dependent decrease in cell proliferation rates was induced at 48h in all AgNP groups, followed by recovery at 72h in the groups coated with 5nm-sized AgNPs. A statistically significant, concentration-dependent antibacterial effect up to 30% was confirmed against both periopathogens., Significance: This study sheds light to the optimal size-related concentrations of AgNP-doped Ti6 Al4 V surfaces to achieve antibacterial effects, without subsequent cytotoxicity. These results significantly contribute to the development of antibacterial surfaces for application in oral implantology., (Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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50. Homoleptic and heteroleptic silver(I) complexes bearing diphosphane and thioamide ligands: Synthesis, structures, DNA interactions and antibacterial activity studies.
- Author
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Varna D, Zainuddin DI, Hatzidimitriou AG, Psomas G, Pantazaki AA, Papi R, Angaridis P, and Aslanidis P
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Cattle, Ethidium chemistry, Ligands, Molecular Conformation, Phosphines chemistry, Spectrometry, Fluorescence, Spectrophotometry, Ultraviolet, Thioamides chemistry, Viscosity, DNA metabolism, Phosphines chemical synthesis, Silver pharmacology, Thioamides chemical synthesis
- Abstract
Three silver(I) complexes bearing different combinations of diphosphanes and N-heterocyclic thioamides or thioamidates as ligands have been synthesized and structurally characterized: the ionic, homoleptic compound [Ag(xantphos)
2 ][BF4 ] (1), where xantphos = 4,5-bis(diphenylphosphano)-9,9-dimethyl-xanthene, and the neutral, heteroleptic compounds [Ag(xantphos)(κ-S-pymt)] (2), where pymt = pyrimidine-2-thiolate, and [AgCl(dppbz)(κ-S-mtdztH)] (3), where dppbz = bis(diphenylphosphano)benzene and mtdztH = 5-methyl-1,3,4-thiadiazole-2-thione. X-ray crystallography studies reveal tetrahedral coordination environments around the silver(I) ions in compounds 1 and 3, while a trigonal planar arrangement of the P2 S donor set has been found around the metal center in compound 2. The interaction of the three compounds with calf-thymus DNA was monitored by UV-vis spectroscopy, DNA-viscosity measurements and indirectly by testing their ability to compete with ethidium bromide for DNA intercalation sites studied by fluorescence emission spectroscopy. Intercalation was revealed as the most possible binding mode for the neutral compounds 2 and 3 and electrostatic interactions for the cationic complex [Ag(xantphos)2 ]+ in 1. Complexes 1-3 have also been found to display moderate in vitro antibacterial activity against the Gram-positive B. cereus, S. aureus and the Gram-negative E. coli bacterial strains, with the homoleptic bis-phosphane silver(I) compound 1 exhibiting a lower activity than the other two neutral compounds., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
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