Advantages of Surface‐Initiated ATRP (SI‐ATRP) for the Functionalization of Electrospun Materials

Surface‐initiated atom transfer radical polymerization (SI‐ATRP) is successfully applied to electrospun constructs of poly(L ‐lactide). ATRP macroinitiators are adsorbed through polyelectrolyte complexation following the introduction of negative charges on the polyester surface through its blending with a six‐armed carboxy‐terminated oligolactide. SI‐ATRP of glycerol monomethacrylate (GMMA) or 2‐(N,N‐diethylamino)ethyl methacrylate (DEAEMA) allows then to grow surface films with controllable thickness, and in this way also to control the wetting and interactions of the construct.     

Thiophene–Diazine Molecular Semiconductors: Synthesis,Structural, Electrochemical,Optical, and Electronic Structural Properties; Implementation in Organic Field‐Effect Transistors

New transportation : New thiophene‐based semiconductors have been produced and studied by electrochemistry, various spectroscopic methods, and structural and morphological techniques in conjunction with model chemistry. Their electrical properties have been analyzed by implementation in field‐effect transistor devices (see figure).

     

New 3,6‐Disubstituted Pyrazolo[1,5‐a]quinazolines as Ligands to GABAA Receptor Subtype

A new series of 3,6‐disubstituted pyrazolo[1,5‐a]quinazolines (PQs) and their 4,5‐dihydro derivatives as isomer of the potent 3,8‐PQ previously reported by us as high affine GABA_A receptor subtype ligands, have been synthesized and evaluated. These new compounds have been obtained exploiting a different synthetic pathway with respect to the corresponding 3,8‐disubstituted isomers, proposing again the same groups present in the reference 3,8‐PQ. The movement of the substituents from position 8 to position 6 is detrimental for binding recognition, suggesting that the substituents at position 6 are not properly oriented to form adequate interaction with hydrogen bond point and lipophilic area in the receptor protein, as demonstrated in molecular modeling studies.     

Application of X-ray fluorescence spectroscopy to provenance studies of Algerian archaeological pottery

The North African regions boast a multimillenary tradition of pottery production that represents a decisive progress in all societies. In this paper, we present the analysis of several fragments of pottery dating from the Middle Ages and collected in the archaeological site of Gouraya in Béjaïa (Algeria). Energy-dispersive X-ray fluorescence measurements were performed to obtain the elemental composition of the clays and to attempt a classification of the samples through multivariate analysis methods, connecting them to the archaeological information about the sites. Hierarchical clusters analysis (HCA) identified two possible different groups, related to different production sites, even if only one source of clay seem to be used, consistently with the geological contest. Based on the results, a tentative provenance interpretation could be proposed on historical bases. We put in place a strategy that made it possible to perform provenance studies respecting sample integrity as we aim to extend our research also to integer and well-preserved object from museum, to create a database for Algerian production of in the Middle Ages.     

Design of a Nasal Spray Based on Cardiospermum halicacabum Extract Loaded in Phospholipid Vesicles Enriched with Gelatin or Chondroitin Sulfate

The extract of Cardiospermum halicacabum L. (C. halicacabum) obtained from flower, leaf and vine was loaded into modified phospholipid vesicles aiming at obtaining sprayable, biocompatible and effective nasal spray formulations for the treatment of nasopharyngeal diseases. Penetration enhancer-containing vesicles (PEVs) and hyalurosomes were formulated, and stabilized by adding a commercial gelatin from fish (20 mg/mL) or chondroitin sulfate from catshark cartilages (Scyliorhinus canicula, 20 mg/mL). Cryo-TEM images confirmed the formation of spherical vesicles, while photon correlation spectroscopy analysis disclosed the formation of small and negatively-charged vesicles. PEVs were the smaller vesicles (~100 nm) along with gelatin-hyalurosomes (~120 nm), while chondroitin-PEVs and chondroitin-hyalurosomes were larger (~160 nm). Dispersions prepared with chondroitin sulfate were more homogeneous, as the polydispersity index was ~0.15. The in vitro analysis of the droplet size distribution, average velocity module and spray cone angle suggested a good spray-ability and deposition of formulations in the nasal cavity, as the mean diameter of the droplets was in the range recommended by the Food and Drug Administration for nasal targets. The spray plume analysis confirmed the ability of PEVs, gelatin-PEVs, hyalurosomes and gelatin-hyalurosomes to be atomized in fine droplets homogenously distributed in a full cone plume, with an angle ranging from 25 to 30°. Moreover, vesicles were highly biocompatible and capable of protecting the epithelial cells against oxidative damage, thus preventing the inflammatory state.     

Interaction enthalpy of lysozyme with vesicles

Negatively charged vesicles made of non-stoichiometric amounts of sodium dodecylsulfate and cetyltrimethylammonium bromide were characterised by physico-chemical methods. Interactions with lysozyme were examined by calorimetry. A remarkable heat effect is observed upon diluting the protein with the vesicular pseudo-solvent. The maximum ΔH_bind value occurs at complete vesicle charge neutralisation by the protein.     

Crystal structure of poly(ω‐pentadecalactone)

The crystal structure of poly(ω‐pentadecalactone) (PPDL) synthesized by enzyme‐catalyzed polymerization was determined by full‐profile refinement. A pseudo‐orthorombic monoclinic unit cell with dimensions a = 7.49(1), b = 5.034(9), and c = 20.00(4)Å (fiber axis), and α = 90.06(4)° hosts two monomeric units belonging to polymer chains with opposite orientation, according to the P2₁ space‐group symmetry. A close similarity to the crystal structure of poly(?‐caprolactone) was evident. However, the even number of backbone atoms in the monomer unit of PPDL leads to a lower crystal symmetry. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1009–1013, 2003