Biocomposite Materials Derived from Andropogon halepensis: Eco-Design and Biophysical Evaluation.

This research work presents a "green" strategy of weed valorization for developing silver nanoparticles (AgNPs) with promising interesting applications. Two types of AgNPs were phyto-synthesized using an aqueous leaf extract of the weed Andropogon halepensis L. Phyto-manufacturing of AgNPs was achieved by two bio-reactions, in which the volume ratio of (phyto-extract)/(silver salt solution) was varied. The size and physical stability of Andropogon-AgNPs were evaluated by means of DLS and zeta potential measurements, respectively. The phyto-developed nanoparticles presented good free radicals-scavenging properties (investigated via a chemiluminescence technique) and also urease inhibitory activity (evaluated using the conductometric method). Andropogon-AgNPs could be promising candidates for various bio-applications, such as acting as an antioxidant coating for the development of multifunctional materials. Thus, the Andropogon-derived samples were used to treat spider silk from the spider Pholcus phalangioides, and then, the obtained "green" materials were characterized by spectral (UV-Vis absorption, FTIR ATR, and EDX) and morphological (SEM) analyses. These results could be exploited to design novel bioactive materials with applications in the biomedical field.

The Role of Biomaterials in Upper Digestive Tract Transoral Reconstruction.

This study aims to establish whether the use of biomaterials, particularly polydimethylsiloxane (PDMS), for surgical reconstruction of the esophagus with templates, Montgomery salivary tube, after radical oncology surgery for malignant neoplasia is an optimal choice for patients' safety and for optimal function preservation and organ rehabilitation. Structural analysis by Raman spectrometry and biomechanical properties with dynamic mechanical analysis are performed for fatigue strength and toughness, essential factors in durability of a prosthesis in the reconstruction practice of the esophagus. Nanocomposites with silicone elastomers and nanoparticles used in implantable devices and in reconstruction surgery present risks of infection and fatigue strength when required to perform a mechanical effort for long periods of time. This report takes into account the effect of silver (Ag) nanoparticles on the fatigue strength using polydimethylsiloxane (PDMS) matrix, representative for silicon elastomers used in implantable devices. PDMS with 5% (wt) Ag nanoparticles of 100-150 nm during mechanical fatigue testing at shear strength loses elasticity properties after 400 loading-unloading cycles and up to 15% shear strain. The fatigue strength, toughness, maximum shear strength, as well as clinical properties are key issues in designing Montgomery salivary tube and derivates with appropriate biomechanical behavior for each patient. Prosthesis design needs to indulge both clinical outcomes as well as design methods and research in the field of biomaterials.

Preparation and Characterization of Silica Nanoparticles and of Silica-Gentamicin Nanostructured Solution Obtained by Microwave-Assisted Synthesis.

In this research work, silica nanoparticles and silica-gentamicin nanostructured solution were synthesized by using the microwave-assisted synthesis, in basic medium, using two silane precursors (tetraethylorthosilicate and octyltriethoxysilane) and the antibiotic (gentamicin sulfate). The prepared materials were characterized through Fourier transform infrared (FTIR) spectroscopy, TGA analysis, transmission electron microscopy (TEM), and atomic force microscopy (AFM) to investigate the morphology and structure. Antimicrobial studies of the silica-gentamicin nanostructured solution versus silica nanoparticles were performed against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. FTIR spectra showed that the gentamicin has been loaded to the silica nanoparticles. AFM analysis showed that the morphology of the silica-gentamicin nanostructured solution has changed, and agglomerations of particles are present at the surface. Antimicrobial testing, performed using the diffusion method through spot inoculation, indicates that the silica-gentamicin nanostructured solution exhibited activity against the resistant strain. The obtained silica-gentamicin solution can be used as biochemical agent for the prevention and treatment of microorganisms which are deposited on different surfaces (e.g., glass, plastic, ceramic).

Identification and prevalence of swine pasivirus 1 in eastern Romanian pig farms.

Swine pasivirus 1 (SPaV-1) was first detected in the feces of healthy pigs in France as a new species in family Picornaviridae. We investigated the presence, distribution, and genetic variability of this virus in 7 geographic areas with intensive pig breeding farms in eastern Romania. A total of 564 porcine specimens, including 82 fecal specimens and 482 pools of organs, were collected from healthy pigs in different stages of production from pathogen-free swine farming units. The virus was found in 6 of 7 areas investigated. Of the 564 samples analyzed, 218 were positive for SPaV-1, with the highest prevalence of the virus in organ homogenates (39% positive) followed by feces (37% positive). The highest susceptibility to infection was found in nurseries (50% positive in both the first and second months of feeding). Sequencing analysis of VP0 revealed 3 different Romanian sequences. The phylogenetic investigations suggest that the Romanian sequences cluster with other Pasivirus strains selected from the GenBank database, forming a separate clade from other Picornaviridae genera and defining the described Pasivirus.

Correlation of XMAP and ELISA cytokine profiles; development and validation for immunotoxicological studies in vitro.

UNLABELLED: There is an emerging trend in immunotoxicological studies to use the multiplex technologies for testing the safety and the efficacy of new pharmaceuticals by using cytokines profiling as biomarker. The Luminex 200 xMAP (multi-analyte profiling) technology provides simultaneous measurement of multiple cytokines in small sample volumes, expressing rapidly the differences between various test compounds. The aim is to develop and validate the Luminex 200 multiplex immunoassays by correlation with ELISA (enzyme-linked immunosorbent assays) for implementation in evaluating cytokine profiling in immunotoxicological studies in vitro. METHODS: Human peripheral whole blood from healthy subject diluted 1+4 with RPMI 1640 was cultured 48 hours in 28 experimental variants: control, in presence of mitogens, bioflavonoid extracts (from Crataegus monogyna and Echinacea purpurea) as cytoprotectors and with a toxic compound [Pb(NO3)2]), separately or variously combined. IL-1beta and IL-2 were comparatively performed by xMAP and ELISA immunoassays from the same sample to initialize validation of multiplex cytokine panel: IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma, usually performed by Luminex 200 system in our immunotoxicological studies. The results indicate similarly typed trends of cytokine values obtained by both methods, with comparable relative changes in presence of mitogens, bioflavonoids and toxic, respectively. Although xMAP absolute cytokine values were higher than ELISA values, the correlation between multiplexed assay and ELISA was good for IL-1beta and IL-2 with positive correlation coefficients near to 1. Conclusions. Quantitative differences between absolute values for IL-1beta and IL-2 obtained by xMAP and ELISA assays are found, but the relative values are comparable and the two methods keep similar trends in similar exposure conditions. The performance parameters of the xMAP assay and the good correlation coefficients with the "gold standard" ELISA recommend to validate the multiplex assay for analyzing cytokine profiles in immunotoxicological studies in vitro.