New Ln(III) complexes as potential optical probes for biological applications

The unique properties of f-f transitions in trivalent lanthanide complexes are the understandable reason of increasing applications in biosensing field, where their long emission lifetimes, the sharp and easily recognizable emission bands in addition to the large shift between the absorbed and emitted radiation besides a short-lived background fluorescence permit the great advantage to isolate their emission signal from the undesired background fluorescence of the biological samples. Furthermore, luminescent complexes of Eu(III) and Tb(III) are the most employed candidates due to the low sensitivity of their excited state to vibrational quenching effects caused by OH, NH, or CH oscillators, frequently present in solution and imaging environments. For these reasons, Eu(III) and Tb(III) complexes have been extensively exploited as sensors of species in physiological conditions, by allowing the detection of relevant clinical biomarkers in biomedical diagnostics and imaging. For these purposes, a high luminescence emission quantum yield and overall luminosity (or brightness) are strongly required and the intensity of the luminescent response, that it is enhanced with heteroaromatic ligands via antenna effect, is usually correlated to the concentration of target analyte. In this PhD project, a library of new water soluble Eu(III) and Tb(III) complexes based on the chiral fragment 1,2-diaminecyclohexane (DACH) has been successfully synthetized, completely characterized (also in solution) and employed for analytical detection of important bio-analytes such as: bicarbonate, L-lactate, serum albumin, and citrate through mainly total luminescence (TL) and circularly polarized luminescence (CPL). These analytes are the main constituents of extracellular fluid, such as human serum

The EMMA Experience. Emerging Patterns and Factors for Success

Since 2008, when the first experiment with MOOCs took place, much has been said, written and explored. However, almost ten years later we are unable to say whether MOOCs are really a desirable learning experience and, moreover, what are the factors for success in the MOOC environment. Literature in the field seems to clearly endorse learner engagement and participation as activities that ensure a higher completion rate and a satisfying learning experience, yet a high degree of dropout can be attributed to a request for participation which learners find unsustainable. On many MOOC projects, the data opens opportunities for discussion but provides few answers, as so much depends on individual variables of the specific course. Far from being a limit of the research, this uncertainty is the only way to preserve learning from becoming a hostage of algorithms, thus leaving teachers and learners the freedom to plan, decide, and experience, and to evaluate their teaching and learning

Physical education teacher training for disability

This work in focused on investigation of physical education teachers’ education with pedagogical bases for students with disabilities. Starting from an American research on teachers of physical education who work in contact with the disability, it has shown how the teachers express negative attitudes towards inclusion because they consider their training inadequate. The aim is to understand the phenomenon of physical education teacher training analysing the documentary research of the master’s degree programs in sports sciences in Italy, with a specific study on the master’s degree in sports sciences at the university of Salerno and, finally, a survey on teachers’ perception of disability. The first study revealed that the main difficulty encountered is the inability to plan inclusive and personalized lessons, since the degree courses refer to the bio-medical area. The second study, the analysis of the Master degree course of Science in Sports Science at the University of Salerno, mainly refers to the pedagogical-didactic area and aimed at teaching and designing for the purpose of education for the disabled. From the fact-finding survey on teachers’ perceptions emerges that both pedagogy and teaching are fundamental for any job in the motor and sports field, even for those who decide not to teach. In conclusion, the training of the physical education teacher who also teaches the disabled must have a less bio-medical and more pedagogical education

High cell density cultivation of Escherichia coli K4 in a microfiltration bioreactor: a step towards improvement of chondroitin precursor production

<p>Abstract</p> <p>Background</p> <p>The bacteria <it>Escherichia coli </it>K4 produces a capsular polysaccharide (K4 CPS) whose backbone is similar to the non sulphated chondroitin chain. The chondroitin sulphate is one of the major components of the extra-cellular matrix of the vertebrate connective tissues and a high value molecule, widely employed as active principle in the treatment of osteoarthritis. It is usually obtained by extraction from animal tissues, but the risk of virus contaminations, as well as the scarceness of raw material, makes this productive process unsafe and unable to satisfy the growing market demand. In previous studies a new biotechnological process to produce chondroitin from <it>Escherichia coli </it>K4 capsular polysaccharide was investigated and a 1.4 g·L^-1K4 CPS concentration was reached using fed-batch fermentation techniques. In this work, on the trail of these results, we exploited new fermentation strategies to further improve the capsular polysaccharide production.</p> <p>Results</p> <p>The inhibitory effect of acetate on the bacterial cells growth and K4 CPS production was studied in shake flask conditions, while a new approach, that combined the optimization of the feeding profiles, the improvement of aeration conditions and the use of a microfiltration bioreactor, was investigated in three different types of fermentation processes. High polysaccharide concentrations (4.73 ± 0.2 g·L^-1), with corresponding average yields (0.13 ± 0.006 g_{K4 CPS}·g_cdw^-1), were obtained; the increase of K4 CPS titre, compared to batch and fed-batch results, was of 16-fold and 3.3-fold respectively, while average yield was almost 3.5 and 1.4 fold higher.</p> <p>Conclusion</p> <p>The increase of capsular polysaccharide titre confirmed the validity of the proposed fermentation strategy and opened the way to the use of the microfiltration bioreactor for the biotechnological production of chondroitin.</p

Targeted Self-Emulsifying Drug Delivery Systems to Restore Docetaxel Sensitivity in Resistant Tumors

The use of chemotherapeutic agents such as docetaxel (DTX) in anticancer therapy is often correlated to side effects and the occurrence of drug resistance, which substantially impair the efficacy of the drug. Here, we demonstrate that self-emulsifying drug delivery systems (SEDDS) coated with enoxaparin (Enox) are a promising strategy to deliver DTX in resistant tumors. DTX partition studies between the SEDDS pre-concentrate and the release medium (water) suggest that the drug is well retained within the SEDDS upon dilution in the release medium. All SEDDS formulations show droplets with a mean diameter between 110 and 145 nm following dilution in saline and negligible hemolytic activity; the droplet size remains unchanged upon sterilization. Enox-coated SEDDS containing DTX exhibit an enhanced inhibition of cell growth compared to the control on cells of different solid tumors characterized by high levels of FGFR, which is due to an increased DTX internalization mediated by Enox. Moreover, only Enox-coated SEDDS are able to restore the sensitivity to DTX in resistant cells expressing MRP1 and BCRP by inhibiting the activity of these two main efflux transporters for DTX. The efficacy and safety of these formulations is also confirmed in vivo in resistant non-small cell lung cancer xenografts

Chlamydia psittaci in ocular adnexa MALT lymphoma: a possible role in lymphomagenesis and a different geographical distribution

Ocular adnexa MALT-lymphomas represent approximatively 5-15% of all extranodal lymphomas. Almost 75% of OAMLs are localized in orbital fat, while 25% of cases involves conjunctive. MALT-lymphomas often recognize specific environmental factors responsible of lymphoma development and progression. In particular as Helicobacter pylori in gastric MALT lymphomas, other bacterial infections have been recognized related to MALT lymphomas in specific site. Recently Chlamydia psittaci has been identified in Ocular Adnexa MALT lymphomas, with variable frequence dependently from geographic areas. Thus bacterial infection is responsible of clonal selection on induced MALT with subsequent lymphoma development. Moreover Chlamydia psittaci could promote chromosomal aberration either through genetic instability as a consequence of induced proliferation and probably through DNA oxidative damage. The most common translocation described in MALT lymphomas affects NF-kB pathway with a substantial antiapoptotic effect. Several therapeutic approaches are now available, but the use of antibiotic-therapy in specific cases, although with conflicting results, could improve the treatment of ocular adnexa MALT lymphomas. In this review we analyse the most relevant features of Ocular adnexa MALT lymphomas, underlining specific biological characteristics mainly related to the potential role of Chlamydia psittaci in lymphomagenesis

Effect of the Heteroaromatic Antenna on the Binding of Chiral Eu(III) Complexes to Bovine Serum Albumin

The cationic enantiopure R) and luminescent Eu(III) complex [Eu(bisoQcd)(H2O)(2)] OTf (with bisoQcd = N,N'-bis(2-isaquinolinmethyl)-trarts-1,2diaminocyclohexane N/N1 -diacetate and OTf = triflate) was synthesized and characterized. At physiological pH, the 1:1 [Eu(bisoQcd)(H2O)(2)](+) species, possessing two water molecules in the inner coordination sphere, is largely dominant. The interaction with bovine serum albumin (BSA) was studied by means of several experimental techniques, such as luminescence spectroscopy, isothermal titration calorimeti-y (ITC), molecular docking (MD), and molecular dynamics simulations M11.-.)S). In this direction, a ligand competition study was also performed by using three clinically established drugs (i.e., ibuprofen, warfarin, and digito)cin). The nature of this interaction is strongly affected by the type of the involved heteroaromatic antenna in the complexes. In fact, the presence of isoqiiinolirie rings drives the corresponding complex toward the protein superficial area containing the tryptophan residue 134 (Trp134). As the main consequence, the metal center undergoes the loss of one water molecule upon interaction with the side chain of a glutamic acid residue. On the other hand, the similar complex containing pyridine rings f[Eti(bpcd)(H2O)(2)]Cl with bpcd = N,N'-bis(2-pytidylmethyl)-trans-1,2-diaminocyclohexane N,N'-diacetate)interacts more weakly with the protein in a different superficial cavity, without losing the coordinated water molecules

Effect of the Counterion on Circularly Polarized Luminescence of Europium(III) and Samarium(III) Complexes

Each enantiopure europium(III) and samarium(III) nitrate and triflate complex of the ligand L, with L = N,N'-bis(2-pyridylmethylidene)-1,2-(R,R + S,S)-cyclohexanediamine ([LnL(tta)2]·NO3 and [LnL(tta)2(H2O)]·CF3SO3, where tta = 2-thenoyltrifluoroacetylacetonate) has been synthesized and characterized from a spectroscopic point of view, using a chiroptical technique such as electronic circular dichroism (ECD) and circularly polarized luminescence (CPL). In all cases, both ligands are capable of sensitizing the luminescence of both metal ions upon absorption of light around 280 and 350 nm. Despite small differences in the total luminescence (TL) and ECD spectra, the CPL activity of the complexes is strongly influenced by a concurrent effect of the solvent and counterion. This particularly applies to europium(III) complexes where the CPL spectra in acetonitrile can be described as a weighed linear combination of the CPL spectra in dichloromethane and methanol, which show nearly opposite signatures when their ligand stereochemistries are the same. This phenomenon could be related to the presence of equilibria interconverting solvated, anion-coordinated complexes and isomers differing by the relative orientation of the tta ligands. The difference between some bond lengths (M-N bonds, in particular) in the different species could be at the basis of such an unusual CPL activity

Eu(iii) and Tb(iii) complexes of 6-fold coordinating ligands showing high affinity for the hydrogen carbonate ion: A spectroscopic and thermodynamic study

In the present contribution, four classes of Ln(iii) complexes (Ln = Eu and Tb) have been synthesized and characterized in aqueous solution. They differ by charge, Ln(bpcd)+ [bpcd2- = N,N'-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane N,N'-diacetate] and Ln(bQcd)+ (bQcd2- = N,N'-bis(2-quinolinmethyl)-trans-1,2-diaminocyclohexane N,N'-diacetate) being positively charged and Ln(PyC3A) (PyC3A3- = N-picolyl-N,N',N'-trans-l,2-cyclohexylenediaminetriacetate) and Ln(QC3A) (QC3A3- = N-quinolyl-N,N',N'-trans-l,2-cyclohexylenediaminetriacetate) being neutral. Combined DFT, spectrophotometric and potentiometric studies reveal the presence, under physiological conditions (pH 7.4), of a couple of equally and highly stable isomers differing by the stereochemistry of the ligands (trans-N,N and trans-O,O for bpcd2- and bQcd2-; trans-O,O and trans-N,O for PyC3A3- and QC3A3-). Their high log\u2009\u3b2 values (9.97 &lt; log\u2009\u3b2 &lt; 15.68), the presence of an efficient antenna effect and the strong increase of the Ln(iii) luminescence intensity as a function of the hydrogen carbonate concentration in physiological solution, render these complexes as very promising optical probes for a selective detection of HCO3-in cellulo or in extracellular fluid. This particularly applies to the cationic Eu(bpcd)+, Tb(bpcd)+ and Eu(bQcd)+ complexes, which are capable of guesting up to two hydrogen carbonate anions in the inner coordination sphere of the metal ion, so that they show an unprecedented affinity towards HCO3- (log\u2009K for the formation of the adduct in the 4.6-5.9 range)