A Multifunctional Polymeric Periodontal Membrane with Osteogenic and Antibacterial Characteristics

Periodontitis is a prevalent chronic, destructive inflammatory disease affecting tooth‐supporting tissues in humans. Guided tissue regeneration strategies are widely utilized for periodontal tissue regeneration generally by using a periodontal membrane. The main role of these membranes is to establish a mechanical barrier that prevents the apical migration of the gingival epithelium and hence allowing the growth of periodontal ligament and bone tissue to selectively repopulate the root surface. Currently available membranes have limited bioactivity and regeneration potential. To address such challenges, an osteoconductive, antibacterial, and flexible poly(caprolactone) (PCL) composite membrane containing zinc oxide (ZnO) nanoparticles is developed. The membranes are fabricated through electrospinning of PCL and ZnO particles. The physical properties, mechanical characteristics, and in vitro degradation of the engineered membrane are studied in detail. Also, the osteoconductivity and antibacterial properties of the developed membrane are analyzed in vitro. Moreover, the functionality of the membrane is evaluated with a rat periodontal defect model. The results confirmed that the engineered membrane exerts both osteoconductive and antibacterial properties, demonstrating its great potential for periodontal tissue engineering.     

Neural Networks Grown on Organic Semiconductors

We report adhesion, growth, and differentiation of mouse neural cells on ultra‐thin films of an organic semiconductor, pentacene. We demonstrate that i) pentacene is structurally and morphologically stable upon prolonged contact with water, physiological buffer, and cell culture medium; ii) neural stem cells adhere to pentacene and remain viable on it for at least 15 days; iii) densely interconnected neural networks and glial cells develop on the pentacene surface after several days. This implies that adhesion proteins secreted by the cells find suitable adsorption loci to anchor the cells. Pentacene is also a suitable substrate for casting thin layers of cell adhesion molecules, such as laminin and poly‐L ‐lysine. Our results show that pentacene, albeit being an aromatic molecule, allows neurons to adhere to and grow on it, which is possibly due to its tightly packed solid state structure. This structure remains unaltered upon exposure to water and interfacial force exerted by the cells. The integration of living cells into organic semiconductors is an important step towards the development of bio‐organic electronic transducers of cellular signals from neural networks.     

Processed vs. Non-Processed Biowastes for Agriculture: Effects of Post-Harvest Tomato Plants and Biochar on Radish Growth,Chlorophyll Content and Protein Production

The aim of this work was to address the issue of processed vs. non-processed biowastes for agriculture, by comparing materials widely differing for the amount of process energy consumption. Thus, residual post harvest tomato plants (TP), the TP hydrolysates obtained at pH 13 and 60 °C, and two known biochar products obtained by 650 °C pyrolysis were prepared. All products were characterized and used in a cultivation of radish plants. The chemical composition and molecular nature of the materials was investigated by solid state ¹³C NMR spectrometry, elemental analysis and potentiometric titration. The plants were analysed for growth and content of chlorophyll, carotenoids and soluble proteins. The results show that the TP and the alkaline hydrolysates contain lignin, hemicellulose, protein, peptide and/or amino acids moieties, and several mineral elements. The biochar samples contain also similar mineral elements, but the organic fraction is characterized mainly by fused aromatic rings. All materials had a positive effect on radish growth, mainly on the diameter of roots. The best performances in terms of plant growth were given by miscanthus originated biochar and TP. The most significant effect was the enhancement of soluble protein content in the plants treated with the lowest energy consumption non processed TP. The significance of these findings for agriculture and the environment is discussed.     

Admittance measurements to assess the total solids and fat contents in liquid whole egg products

In the present research, a method based on admittance measurements able to assess total solids and fat contents (%) in nine different liquid whole egg products was set up. By means of a tetrapolar platinum cell connected to a signal conditioning circuit, an alternating current generator and a data acquisition system, the effect of 15 different combinations of frequencies of the oscillating field (10, 100, 500, 1000 and 5000 Hz) and input voltage levels (1, 1.5 and 2 V) on the estimation of the total solids and fat contents were analyzed. The influence of the temperature solution on the electrical measurements was also assessed. The best estimations were obtained at 1000 Hz and 1 V (R² = 0.998; SE = 0.14%) for the total solids content and at 5000 Hz and 1 V (R² = 0.995; SE = 0.19%) for the fat content. For both parameters, the measurements conducted at 10 Hz appeared affected by the polarization occurring at the electrodes-solution interface. The admittance of the liquid whole egg products linearly increased with the temperature, and a temperature coefficient θ at 20 °C of about 2.1 was calculated. These excellent results encourage an industrial application of the technique for a rapid and economic assessment of the total solids and fat contents in the liquid egg products.     

Enantioselective Gas Chromatography with Derivatized Cyclodextrins in the Flavour and Fragrance Field

This article deals with enantioselective gas chromatography (Es-GC) utilizing cyclodextrin derivatives as chiral stationary phases (CSPs) for chiral recognition in the flavour and fragrance field. It consists of two main parts. The first one concerns cyclodextrins and their use in Es-GC, and it deals with their introduction and evolution as CSPs in GC, together with some theoretical aspects involved with enantiomeric separation and their consequent influence on routine chiral recognition. The second part reports on the strategy of chiral recognition in routine analysis with cyclodextrin derivatives as CSP, illustrated with examples from the authors’ everyday experiences. This part describes how to identify enantiomers or to measure their excess or ratio determination in complex mixtures; in particular, it discusses the opportunities offered by multidimensional and fast GC techniques, the role of mass spectrometry, and the application of total analysis systems to chiral recognition.     

Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration

Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds.     

Performance study of ionic liquid in extraction based on single-drop experiments

Experiments of single-drop sedimentation and mass transfer on a laboratory scale for the extraction of acetone from a water + acetone mixture by means of the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF₆) were performed at a temperature of 298.2 K and ambient pressure. Study of the system equilibrium conditions in a previous work (Saien et al., 2015) showed that HMIMPF₆, as a green solvent for the extraction of acetone from aqueous solutions, has suitable capability. The single-drop experiments with this system show that the mass transfer is not as slow as expected despite the relatively high viscosity of the system. The Henschke model is applied to the obtained data for the challenging system involving an ionic liquid by determining appropriate values for the corresponding material-specific model parameters. This model describes the experimental data with very good accuracy.