A Practical Approach for the In Vitro Safety and Efficacy Assessment of an Anti-Ageing Cosmetic Cream Enriched with Functional Compounds

(1) Background: Cosmeceuticals are topical products applied to human skin to prevent skin ageing and maintain a healthy skin appearance. Their effectiveness is closely linked to the compounds present in a final formulation. In this article, we propose a panel of in vitro tests to support the efficacy assessment of an anti-ageing cream enriched with functional compounds. (2) Methods: biocompatibility and the irritant effect were evaluated on reconstructed human epidermis (RHE) and corneal epithelium (HCE) 3D models. After a preliminary MTT assay, normal human dermal fibroblasts (NHDF) and keratinocytes (HaCaT) were used to evaluate the extracellular matrix (ECM) protein synthesis, and interleukin-6 (IL-6) and metalloproteinase-1 (MMP-1) production. (3) Results: data collected showed good biocompatibility and demonstrated the absence of the irritant effect in both 3D models. Therefore, we demonstrated a statistical increase in collagen and elastin productions in NHDF cells. In HaCaT cells, we highlighted an anti-inflammatory effect through a reduction in IL-6 levels in inflammatory stimulated conditions. Moreover, the reduction of MMP-1 production after UV-B radiation was demonstrated, showing significant photo-protection. (4) Conclusion: a multiple in vitro assays approach is proposed for the valid and practical assessment of the anti-ageing protection, anti-inflammatory and biocompatible claims that can be assigned to a cosmetic product containing functional compounds.     

Design and characterization of a homodimeric antiparallel coiled coil

We report the first successful design of a self-associating antiparallel coiled coil, APH. The simultaneous application of Coulombic and hydrophobic components results in a decided preference for the antiparallel alignment as judged by HPLC, sedimentation equilibrium, and chemical denaturation data. The designed peptide is of comparable stability to naturally occurring leucine zipper peptides and can be expressed in bacteria. These properties of APH suggest potential in vivo protein fusion and biomaterials applications.     

Squaric acid N-hydroxylamides: synthesis, structure, and properties of vinylogous hydroxamic acid analogues

The synthesis of squaric acid N-hydroxylamide esters 5 and amides 6 from dimethyl squarate 2a is described. These derivatives are analogues of the naturally occurring iron(III) chelator hydroxamic acid. On the basis of a comparative reactivity study, a concerted retro-Cope mechanism for the formation of the N-hydroxylamide esters 5 by reaction of dimethyl squarate with hydroxylamines is proposed. A preliminary iron(III) binding study of these hydroxamic acid analogues is presented, demonstrating binding of iron(III) to amides 6 in aqueous solutions, while the esters 5 did not show any sign of metal ion binding. 13C NMR spectroscopic data (chemical shift and spin-lattice relaxation time determination) of these and related derivatives delineate the resonance structures predominant in these molecules. The resonance structures of the derivatives rationalize their spectroscopic data, chemical reactivity, and iron(III) binding properties. Single-crystal X-ray structure analyses of squaric acid N-hydroxylamide ester 5b and squaric acid N-hydroxylamide amide 6c confirm their connectivity and provide structural evidence supporting the spectroscopically derived conclusions. The squaric acid N-hydroxylamides are potentially useful in the construction of chemosensors for iron(III).     

Pictorial representation of three-dimensional electron distributions through a perspective view of contour diagrams in a set of parallel planes

A method of graphically exhibiting detailed information about a three-dimensional electron distribution function f(x,y,z) is described. Contour lines f = constant are drawn on a set of equidistant parallel planes that intersect the distribution, and a perspective view of all contours on all planes is displayed. Representative examples are given.     

Interference of ruthenium red analogues at photosystem II of spinach thylakoids

The effect of ruthenium red analogues on several thylakoid photosynthetic activities has been investigated. RR, RV, RRPh1, RRPh2 and Ph inhibit ATP synthesis and electron flow from water to MV (basal, phosphorylating and uncoupled) as their concentration increases, thus, they act as a Hill reaction inhibitor. They inhibit uncoupled electron transport through PSII from water to DCPIP and partially from DPC to DCPIP. However, these compounds do not affect uncoupled PSI electron transport from DCPIP to MV. Therefore, the target of interaction is at the level of OEC and the span P(680) to Q(A) for RR, RRPh1 and RRPh2. Chlorophyll a fluorescence studies corroborate the already found interference sites and may affect the disconnection between chlorophyll molecules within the LHCII and/or between antennae and RCs, or decreases the exciton to reach the RC and inhibition of PSII occurs. RRPh2 is six times more active than RR. Finally, Ph inhibits electron flow interacting at the level of Q(B).     

Preparation of poly(methyl methacrylate) and copolymers having enhanced thermal stabilities using sucrose-based comonomers and additives

A series of methyl methacrylate polymers have been prepared containing sucrose-based crosslinkers and additives. Thermogravimetry and long-term aging studies at 200°C show that sucrose-based alkyl and allyl ethers provide unprecedented thermal stability to linear, as well as crosslinked, poly (methyl methacrylate) or PMMA. Linear PMMA and PMMA crosslinked with trimethylolpropane trimethacrylate (TMPTMA) both degrade at 284°C. PMMA containing octa-O-crotylsucrose (1 mol %) degraded at 322°C. Depending on concentration, PMMA containing octa-O-allylsucrose (0.1-1.0 mol % and higher) degraded between 334 and 354°C, and PMMA containing 1′,6,6′-trimethacryloyl-2,3,3′,4,4′-penta-O-methylsucrose (0.1-1.0 mol %) degraded between 309 and 320°C. PMMA containing (1 mol % each) sucrose-based esters, ester-ether derivatives, all degraded at or below the degradation temperature of pure PMMA. Long-term air aging studies revealed that PMMA containing penta-O-methylsucrose trimethacrylate, octa-O-allylsucrose, and octa-O-crotylsucrose did not flow or sag after heating for 24 h at 200°C, but the polymers did show yellowing. While linear and crosslinked samples of PMMA containing compounds other than sucrose ethers lost more than 50% of their original weight within 15 h at 200°C, PMMA containing sucrose-based ethers lost about 8 and 20% of their original weight after 1 and 8.5 days, respectively. Herein we propose a unique mechanism by which saccharide ethers may be imparting this unprecedented thermal stabilization to PMMA. While tertiary hydrogens alpha to oxygens in saccharide ethers are stable to chain transfer during normal polymerization temperatures, they readily chain transfer at 200°C where PMMA is unstable. Chain transfer of these hydrogens is followed by fragmentation to produce alkyl, allyl or crotyl radicals, which combine with the macroradicals and terminate depropagation. © 1995 John Wiley & Sons, Inc.     

Comprehensive characterization of the N-glycosylation status of CD44s by use of multiple mass spectrometry-based techniques

The CD44 family are type-1 transmembrane glycoproteins which are important in mediating the response of cells to their microenvironment, including regulation of growth, survival, differentiation, and motility. All these important functions have been reported to be regulated by N-glycosylation; however, little is known about this process. In the CD44 family, the most prolific isoform is CD44 standard type (CD44s). In this work, an integrated strategy combining stable isotope labeling, chemical derivatization, hydrophilic-interaction liquid chromatographic (HILIC) separation, and mass spectrometric (MS) identification was used to perform a comprehensive qualitative and quantitative survey of the N-glycosylation of recombinant CD44s. Specifically, the occupation ratios of the N-glycosites were first determined by MS with (18)O labeling; the results revealed five glycosites with different occupation ratios. Next, N-glycans were profiled by chemical derivatization and exoglycosidase digestion, followed by MALDI-TOF-MS and HILIC-ESI-MS-MS analysis. Interestingly, the quantitative analysis showed that non-sialylated, fucosylated complex-type glycans dominated the N-glycans of CD44s. Furthermore, the site-specific N-glycan distributions profiled by LC-ESI-MS(E) indicated that most glycosites bore complex-type glycans, except for glycosite N100, which was occupied by high-mannose-type N-glycans. This is the first comprehensive report of the N-glycosylation of CD44s. Figure Strategies for characterization of the N-glycosylation status of CD44s.     

At-line bioprocess monitoring by immunoassay with rotationally controlled serial siphoning and integrated supercritical angle fluorescence optics

In this paper we report a centrifugal microfluidic “lab-on-a-disc” system for at-line monitoring of human immunoglobulin G (hIgG) in a typical bioprocess environment. The novelty of this device is the combination of a heterogeneous sandwich immunoassay on a serial siphon-enabled microfluidic disc with automated sequential reagent delivery and surface-confined supercritical angle fluorescence (SAF)-based detection. The device, which is compact, easy-to-use and inexpensive, enables rapid detection of hIgG from a bioprocess sample. This was achieved with, an injection moulded SAF lens that was functionalized with aminopropyltriethoxysilane (APTES) using plasma enhanced chemical vapour deposition (PECVD) for the immobilization of protein A, and a hybrid integration with a microfluidic disc substrate. Advanced flow control, including the time-sequenced release of on-board liquid reagents, was implemented by serial siphoning with ancillary capillary stops. The concentration of surfactant in each assay reagent was optimized to ensure proper functioning of the siphon-based flow control. The entire automated microfluidic assay process is completed in less than 30 min. The developed prototype system was used to accurately measure industrial bioprocess samples that contained 10 mg mL⁻¹ of hIgG.     

1H, 13C and 15N NMR assignments of phenazopyridine derivatives

Phenazopyridine hydrochloride (1), a drug in clinical use for many decades, and some derivatives were studied by one- and two-dimensional (1)H, (13)C and (15)N NMR methodology. The assignments, combined with DFT calculations, reveal that the preferred protonation site of the drug is the pyridine ring nitrogen atom. The chemoselective acetylation of phenazopyridine (2) and its influence on the polarization of the azo nitrogen atoms were evidenced by the (15)N NMR spectra. Molecular calculations of the phenazopyridines 2-4 show that the pyridine and phenyl groups are oriented in an antiperiplanar conformation with intramolecular hydrogen bonding between the N-b atom and the C-2 amino group preserving the E-azo stereochemistry.     

Gas-phase halonium metathesis and its competitors. Skeletal rearrangements of cationic adducts of saturated ketones

The methyl cation and CF(3)(+) attack saturated, acyclic ketones to make vibrationally excited adduct ions. Despite their high internal energies and short lifetimes, these adducts undergo deep-seated rearrangements that parallel slower processes in solution. Observed pathways include alkene and alkane expulsions, in addition to (in the case of CF(3)(+)) the precedented loss of CF(2)O + HF. For the vast majority of ketones, the principal charged products are the CF(3)(+) adducts of lighter carbonyl compounds, ions that are not easily prepared by other avenues. Evidence for ion structures comes from collisionally activated unimolecular decomposition and bimolecular ion-molecule reactions. Typical examples are di-n-propyl and diisopropyl ketones (both of which produce CH(3)CH=OCF(3)(+) as the principal ion-molecule reaction product) and pentamethylacetone (which produces (CH(3))(2)C=OCF(3)(+) as virtually the sole ion-molecule reaction product). Isotopic labeling experiments account for mechanisms, and DFT calculations provide a qualitative explanation for the relative abundances of products from unimolecular decompositions of the chemically activated CF(3)(+) adduct ions that are initially formed.