Physicochemical and drug delivery aspects of lipid-based liquid crystalline nanoparticles: a case study of intravenously administered propofol

Liquid crystalline nanoparticles (LCNP) formed through lipid self-assembly have a range of attractive properties as in vivo drug delivery carriers. In particular they offer: a wide solubilization spectrum, and consequently high drug payloads; effective encapsulation; stabilization and protection of sensitive drug substances. Here we present basic physicochemical features of non-lamellar LCNP systems with a focus on intravenous drug applications. This is exemplified by the formulation properties and in vivo behavior using the drug substance propofol; a well-known anesthetic agent currently used in clinical practice in the form of a stable emulsion. In order to appraise the drug delivery features of the LCNP system the current study was carried out with a marketed propofol emulsion product as reference. In this comparison the propofol-LCNP formulation shows several useful features including: higher drug-loading capacity, lower fat-load, excellent stability, modified pharmacokinetics, and an indication of increased effect duration.     

Electrochemical gold deposition from sulfite solution: application for subsequent polyaniline layer formation

Electrochemical gold deposition from sulfite solutions was studied by means of voltammetry, EIS and EQCM. A gold film electrode was used for polyaniline layer formation by electrochemical oxidation of aniline. The standard electrochemical reduction potential of the reaction [Au(SO₃)₂]³⁻ + e⁻ = Au + 2 SO₃²⁻ was determined, and is equal to 0.116 V (vs. NHE). Both solution stirring and temperature increase accelerate the electrochemical reduction of gold, when the electrode potential is below −0.55 V. When the potential is above −0.55 V the electrochemical reduction proceeds via passive layer formation. Our study suggests that the passive layer consists of chemically adsorbed sulfite ions and sulfur. The gold film deposited from sulfite solution is a high quality substrate suitable for conducting polymer layer formation. This technique, where a polymer layer electrode is prepared by thin gold film deposition onto a metal surface and by subsequent polymer layer formation, can be applied in sensor research and technology.     

FK6-12 texturizing machine

FK6-12 texturizing machine     

Self-assembled lipid superstructures: beyond vesicles and liposomes

A unique set of nanoparticle dispersions of self-assembled lipid mesophases with distinctive reversed cubic, hexagonal, and sponge phase structures has been prepared by use of original lipid combinations and a simple, generally applicable and scalable method. All key properties, particle size distributions, shape, phase structure, and stability, are controlled predictably and reproducibly. The results suggest the cross-disciplinary use of nonlamellar particle structures in science and technology as, for instance, biomimetics, in vivo drug delivery vehicles for diagnostic and therapeutic agents, protein crystallization matrices, and soft nanoporous materials.     

Braiding Simulation and Prediction of Mechanical Properties

Rotary braiding is a cost effective method to manufacture near net shaped preforms that generally have a closed section and may have an arbitrary shape if braiding is performed over a shaped mandrel. The reinforcement architecture can be varied by the number and spacing of active bobbins, and by the speeds used to ‘take-up’ the braid and move the circumferential bobbins. Analytical methods are available that can reliably predict yarn paths and the final braid meso-structure for simple regular sections, and further analytical methods have been proposed to estimate composite braid elastic mechanical properties. A full simulation chain using the explicit Finite Element (FE) technique is presented for composite braid manufacture and mechanical stiffness prediction of the final composite. First simulation of the braiding process provides detailed information on yarns paths and braid meso-structure, from which Representative Volume Elements (RVE) of the braid may be constructed for analysis of stiffness properties. The techniques are general and can be applied to any braid geometry. A specific problem of meshing the yarn structure and interspersed resin volumes is overcome using conventional solid elements for the yarns and Smooth Particle Hydrodynamics for the resin, with link element to join the two constituents. Details of the background theory, braid simulation methods, meso- model analysis and validation again analytical and test measurements are presented.     

Detection of Salmonella spp., Yersinia enterocolitica,Listeria monocytogenes and Campylobacter spp. by real‐time multiplex PCR using amplicon DNA melting analysis and probe‐based assay

Syto9 and probe‐based multiplex real‐time PCR assays for simultaneous detection of a group of foodborne pathogens (named SYLC group), targeting Salmonella spp. (invA gene), Yersinia enterocolitica (ystA gene), Listeria monocytogenes (hly gene) and Campylobacter spp. (rrna gene), have been developed. The Syto9 assay generates amplicon DNA melting curve with four peaks of 86.5 ± 0.5, 84 ± 0.5, 81.5 ± 0.5 and 90.5 ± 0.5 °C corresponding Salmonella spp., Y. enterocolitica, L. monocytogenes and Campylobacter spp. targets, respectively. The sensitivities of the Syto9 and TaqMan assays in artificially inoculated chicken wing rinses were in a range of 3.2 × 10² to 3.1 × 10⁴ and 9.8 × 10² to 1.9 × 10⁴ colony‐forming units per millilitre, respectively, depending on the pathogen. All tested target strains (n = 100) were correctly detected by the both assays, whereas nontarget strains (n = 100) demonstrated no cross‐reactivity representing 100% specificity. The assays are suitable for application in qualitative and quantitative detection of SYLC group pathogens in food matrices.