Towards Selective Delivery of a Ruthenium(II) Polypyridyl Complex-Containing Bombesin Conjugate into Cancer Cells

An increasing number of novel Ru(II) polypyridyl complexes have been successfully applied as photosensitizers (PSs) for photodynamic therapy (PDT). Despite recent advances in optimized PSs with refined photophysical properties, the lack of tumoral selectivity is often a major hurdle for their clinical development. Here, classical maleimide and versatile NHS-activated acrylamide strategies were employed to site-selectively conjugate a promising Ru(II) polypyridyl complex to the N-terminally Cys-modified Bombesin (BBN) targeting unit. Surprisingly, the decreased cell uptake of these novel Ru-BBN conjugates in cancer cells did not hamper the high phototoxic activity of the Ru-containing bioconjugates and even decreased the toxicity of the constructs in the absence of light irradiation. Overall, although deceiving in terms of selectivity, our new bioconjugates could still be useful for advanced cancer treatment due to their nontoxicity in the dark.     

Chemical Composition and Ability of Essential Oils from Six Aromatic Plants to Counteract Lipid Oxidation in Emulsions

Essential oils with antioxidant properties are of increasing interest in West Africa where there are many antioxidant rich plants. The objective of this study was to determine the essential oil extracted from six native plants (Lippia multiflora, Lippia rugosa, Monodora tenuifolia, Ocimum gratissimum, Pimenta racemosa, Cymbopogon citratus) extracted by hydrodistillation from local plants in Benin. These samples were also evaluated for their antioxidant capacity using the conjugated autoxidizable triene (CAT) assay performed in stripped tung oil-in-water emulsion. The essential oil of P. racemosa, containing high amounts of chavicol (10.3 %) and eugenol (54.5 %), showed the strongest antioxidant activity, followed by that from O. gratissimum containing large amounts of thymol (50.2 %). The essential oil extracted from M. tenuifolia exhibited a moderate antioxidant activity. This essential oil is primarily composed of sesquiterpene alcohols such as α-cadinol (20.5 %), its isomer, α-muurolol (14.7 %), and germacrene D-4-ol (16.8 %). Essential oils from L. multiflora, L. rugosa and C. citratus oils showed poor ability to protect tung oil from oxidation. Finally, essential oils containing phenolic compounds and, in a lesser extent, sesquiterpene alcohols, exhibited the highest CAT values indicating that these compounds are the key determinants of the antioxidant activity of these essential oils in oil-in-water emulsions.     

Quantitative imaging of nonlinear shear modulus by combining static elastography and shear wave elastography

The study of new tissue mechanical properties such as shear nonlinearity could lead to better tissue characterization and clinical diagnosis. This work proposes a method combining static elastography and shear wave elastography to derive the nonlinear shear modulus by applying the acoustoelasticity theory in quasi-incompressible soft solids. Results demonstrate that by applying a moderate static stress at the surface of the investigated medium, and by following the quantitative evolution of its shear modulus, it is possible to accurately and quantitatively recover the local Landau (A) coefficient characterizing the shear nonlinearity of soft tissues.     

Cryptic Color Change in a Crab Spider (<Emphasis Type=Italic>Misumena vatia</Emphasis>): Identification and Quantification of Precursors and Ommochrome Pigments by HPLC

Mimicry is used widely by arthropods to survive in a hostile environment. Often mimicry is associated with the production of chemical compounds such as pigments. In crab spiders, the change of color is based on a complex physiological process that still is not understood. The aim of this study was to identify and quantify the ommochrome pigments and precursors responsible for the color change in the mimetic crab spider Misumena vatia (Thomisidae). A modified high performance reverse phase ion-pair chromatography technique enabled us to separate and quantify the ommochrome pigments, their precursors, and related metabolites in individual spiders. Compounds such as tryptophan, kynurenine, and kynurenic acid occurred only or mainly in white crab spiders. In contrast, compounds such as 3-hydroxy-kynurenine, xanthommatin, and ommatin D occurred only or mainly in yellow crab spiders. Factor analysis ranked the different color forms in accordance with their metabolites. The biochemical results enabled us to associate the different phases of formation of pigment granules with specific metabolites. Yellow crab spiders contain many unknown ommochrome-like compounds not present in white crab spiders. We also found large quantities of decarboxylated xanthommatin, whose role as precursor of new pathways in ommochrome synthesis needs to be assessed. The catabolism of ommochromes, a process occurring when spiders revert from yellow to white, warrants further study.     

Glycerol Partial Oxidation over Pt/Al2O3 Catalysts under Basic and Base-Free Conditions—Effect of the Particle Size

The glycerol partial oxidation reaction over Pt/Al₂O₃ catalysts was studied under basic (NaOH/GLY molar ratio 4) and base-free conditions (NaOH/GLY molar ratio 0). Catalysts with small (2.95 nm) and large particle sizes (260.83 nm) were synthesized according to the use of different reducing agents, formaldehyde or sodium borohydride, and hydrazine, respectively. These different Pt particle sizes lead to a dramatic change in terms of activity, irrespective of the applied conditions. The biggest particles (i.e., 260 nm) seem to generate overoxidation products leading to a decrease in the carbon balance (to ~80%) while the smallest particles exhibit the highest initial glycerol transformation rate (i.e., ~10,000 mol h⁻¹ mol_Pt⁻¹ under basic conditions at 60°C and ~2000 mol h⁻¹ mol_Pt⁻¹ in the absence of a base at 100°C). In terms of selectivities, the main products are different as a function of the initial reaction conditions. For base-free conditions, the two main products are glyceraldehyde and glyceric acid with a sum of selectivities always larger than 80%. Under basic conditions, the major product is glyceric acid while no trace of glyceraldehyde is detected.     

Succinylation of Non-ionic Surfactants: Physicochemical Characterization,Functional Properties,Biodegradability and Mathematical Modeling of the Polarity Tuning

Anionic surfactants comprising succinic acid end groups were synthesized by succinylation of non-ionic surfactants using succinic anhydride as a potentially bio-sourced building block. A solvent- and catalyst-free synthesis was designed for succinic anhydride mono esterification with octyl-, decyl and dodecylpolyxylosides, di- and tetraethylene glycol dodecylethers and glycerol monolaurate. The physicochemical and functional properties of anionic surfactants thus obtained were studied and compared with their non-succinylated counterparts. A correlation between these properties and the polarity changes induced by the addition of the hydrophilic succinic acid moiety was established. The biodegradability of the succinylated surfactants has also been investigated. Finally, through a desirability function approach, mathematic predictions were correlated to the properties in order to find an optimum and to discriminate surfactants with respect to targeted physicochemical properties and resulting applications.     

Development and population study of an eight-locus short tandem repeat (STR) multiplex system

Amplification of short tandem repeat (STR) loci has become a useful tool for human identification applications. To improve throughput and efficiency for such uses, the polymorphic STR loci CSF1PO, TPOX, TH01, vWA, D16S539, D7S820, D13S317, D5S818, F13A01, FESFPS, F13B, and LPL have been evaluated, developed, and configured into fluorescently labeled multiplex systems. Eight of these STR loci were combined to generate the PowerPlex System, a two-color multiplex system that supports rapid, accurate, reliable analysis and designation of alleles. The remaining four loci comprise the FFFL System, a one-color multiplex system. The PowerPlex System may be evaluated alternatively as two one-color, four-locus multiplex systems, CTTv Multiplex and GammaSTR Multiplex. The products of multiplex amplification may be analyzed with a variety of fluorescence detection instruments. Determination of genotypes of over 200 individuals from each of three different population/ethnic groups revealed independence of inheritance of the loci and allowed calculation of matching probability, typical paternity index, and power of exclusion for each multiplex.     

Reuse of denaturing polyacrylamide gels for short tandem repeat analysis

Denaturing polyacrylamide gel electrophoretic analysis of amplified polymorphic short tandem repeat (STR) loci using fluorescent markers is a mainstay of forensic and paternity testing. To reduce the drawback of preparing gels or using expensive precast gels, we have developed a simple and rapid method to reuse gels between 2 and 8 times over a period of several days. Following the initial electrophoresis and scan, the original samples are removed from the gel by a 1-1.5-h reverse-electrophoresis step. This step heats the gel for the next set of samples and can be performed several days after the initial electrophoresis. Sample bands remain sharp on subsequent runs, but edge effects (frowning of the outside lanes) become progressively worse and ultimately limit gel reuse. Well distortions and separation of the gel from the plates become problems if the gel is used more than twice. However, degassing the gel solution and bonding the gel to both plates eliminate these problems. Precast gels also can be used multiple times. Using this technique, we have successfully analyzed samples amplified with a nine-locus multiplex system and characterized the separated products using a fluorescent scanner and software.     

Characterization of Olive-Leaf Phenolics by ESI-MS and Evaluation of their Antioxidant Capacities by the CAT Assay

Olive leaves are a very abundant vegetable material containing various phenolic compounds, such as secoiridoids and flavonoids, that are expected to exert strong antioxidant capacity. However, little is known about the variation of olive-leaf phenolic composition during maturation and its influence on antioxidant capacity. To answer this question, young and mature Olea Europaea L. leaves were submitted to successive extraction with dichloromethane, ethyl acetate, and methanol, then characterized by ESI-MS. It appeared that mature olive-leaf extracts contained higher levels of verbascoside isomers and glucosylated forms of luteolin, while young ones presented higher contents of oleuropein, ligstroside, and flavonoid aglycones. Moreover, antioxidant capacity evaluation using our newly developed conjugated autoxidizable triene assay showed that, in a lipid-based emulsified system, this phenolic composition variation leads to a change in the ability of extracts to counteract lipid oxidation. Mature olive-leaf extracts exhibit higher antioxidant capacity than young olive-leaf extracts. This result enables us to hypothesize that two main bioconversion scenarios may occur during maturation of olive leaves, which could explain changes observed in antioxidant capacity: (1) a bioconversion of oleuropein and ligstroside into verbascoside isomers and oleuroside, and (2) a bioconversion of flavonoid aglycones into glucosylated forms of luteolin. Finally, this study leads to a better understanding of the relationship between phenolic profile and antioxidant capacity of olive leaves.     

Water intrusion in mesoporous silicalite-1: An increase of the stored energy

In silicalite-1 (pure silica MFI-type zeolite), the water adsorption is extremely weak when the pressure is lower than the water saturation vapor pressure. The water condensation (intrusion) is obtained by applying a high hydraulic pressure, approximately of 100 MPa. Extrusion of water occurring at the similar pressure, the “water–silicalite-1” system constitutes thus a real molecular spring, which can store and restore mechanical energy. In order to increase the stored energy in this system, the porous volume of this zeolite was increased by the creation of additional micro-, meso- and macropores using carbon black or surfactant [3-(trimethoxysilyl)propyl]hexadecyldimethylammonium chloride, as porogen and templating agents, respectively. The presence of meso- and macropores modifies the water condensation behavior in silicalite-1. Indeed, the water intrusion takes place in two stages. The first one, from 3 to 7 MPa, corresponds to the filling of meso- and macropores but the amount of stored energy is very low. The second one, at 100 MPa, corresponds to the filling of micropores. The increase of the microporous volume leads to an increase of the intruded water volume at high hydraulic pressure. Consequently, the stored energy is greater than for a conventional silicalite-1 zeolite.