Five Novel Polymorphs of Cardarine/GW501516 and Their Characterization by X-ray Diffraction, Computational Methods, Thermal Analysis and a Pharmaceutical Perspective.

GW501516, also known by the name of cardarine, is a synthetic peroxisome-proliferator-activated receptor delta (PPR-δ) agonist agent developed for applications in the treatment of metabolic disorders and cardiovascular diseases. A broad polymorph screening in various solvents and mixtures was completed in order to explore its capabilities to grow polymorphs. The crystal structures of four polymorphs were elucidated using single-crystal X-ray diffraction, while one structure was solved via a powder X-ray diffraction method. The solid state features (nature of intermolecular interactions) were investigated by computational methods. The polymorphs were further investigated by thermal DSC analysis and X-ray diffraction on powders. From a pharmaceutical perspective, the stability and solubility of the polymorphs were analyzed as well.

Structural Insights and Intermolecular Energy for Some Medium and Long-Chain Testosterone Esters.

Testosterone (17ß-Hydroxyandrost-4-en-3-one) is the primary male anabolic-androgenic steroid. The crystal structures of two medium and two long esterified forms of testosterone, including enanthate, cypionate, decanoate and undecanoate, were determined by X-ray single crystal diffraction. The samples were also characterized by powder X-ray diffraction, FT-IR spectroscopy and thermal analysis (DTA, TG). Crystal packings and supramolecular features were described. The analysis of structural features was accomplished by computational methods in terms of the type of intermolecular interactions, crystal energies and Hirshfeld surfaces analysis. From a pharmaceutical point of view, the solubility of compounds was investigated.

New Composite Hydrogel Based on Whey and Gelatin Crosslinked with Copper Sulphate.

By-products from the meat and dairy industries are important sources of high biological value proteins. This paper explores possibilities for improving the swelling and integrity of a cross-linked whey and gelatin hydrogel with different amounts of CuSO4 × 5H2O. Overall, swelling tests demonstrate that cross-linked samples show a better hydration capacity and stability in the hydration medium, but different copper concentrations lead to different swelling behavior. At concentrations smaller than 0.39%, the sample lasts for 75 h in a water environment before beginning to disintegrate. At a concentration of copper sulphate higher than 0.55%, the stability of the sample increased substantially. The swelling kinetics has been investigated. The diffusion constant values increased with the increase in copper concentration, but, at the highest concentration of copper (0.86%), its value has decreased. Spectroscopy analyses such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), and nuclear magnetic resonance (NMR) relaxometry analyses revealed changes in the secondary and tertiary structure of proteins as a result of the interaction of Cu2+ ions with functional groups of protein chains. In addition to its cross-linking ability, CuSO4 × 5H2O has also shown excellent antibacterial properties over common bacterial strains responsible for food spoilage. The result of this research demonstrates the potential of this hydrogel system as a unique material for food packaging.

Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach.

Calcium nitrate is considered a promising accelerator in cement-based composites, with high potential in 3D printing and cold cement concreting. The effect induced by the composition of calcium nitrate tetrahydrate (CN) accelerator into white Portland cement is evaluated here from three perspectives: (1) Fresh cement paste properties in terms of setting time and slump, (2) mechanical properties of hardened cement samples at 7 and 28 days and (3) material characteristics in terms of structure and porosity that further link the presence of the accelerator with the macroscopic performances. The compressive and flexural strength of the hardened samples, evaluated after 7 and 28 days of hydration, indicate a non-monotonous trend with CN concentration. Crystalline phase composition is investigated using X-ray diffraction (XRD). The morphology and texture are analyzed at the flexure interface by visual inspection and electron microscopy. Complementary, the porous features are investigated by NMR-relaxometry on dry and cyclohexane-filled samples. The studies confirm that CN promotes changes in the composition and morphology of hydrates, while a trend of increase in capillary porosity is outlined as well. This competition between multiscale effects may be quantified by NMR and complementary techniques to further clarify the mechanical behavior of such composites.

Electrospun Membranes Based on Polycaprolactone, Nano-Hydroxyapatite and Metronidazole.

The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young's modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP filler and decreased when MET was added. New EMs with nHAP and MET could be promising materials for guided bone regeneration or tissue engineering.

Effects of Copper Metallic Nanoparticles on Structural and Optical Properties of Antimony Phosphate Glasses Co-Doped with Samarium Ions.

New antimony phosphate glasses doped with samarium (III) oxide and co-doped with copper metallic nanoparticles (CuNPs) were obtained by the melt quenching technique. The samples were analyzed by X-ray diffraction analysis (XRD), electron paramagnetic resonance (EPR), ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopies. XRD data suggested that all the obtained samples showed an amorphous nature. EPR data suggested the existence of Cu2+ ions octahedrally surrounded by six oxygen atoms. The dipole-dipole interactions between Cu2+ ions were predominant. UV-Vis spectra revealed the presence of Sm3+ and Cu2+ ions in the samples. The values for nephelauxetic and bonding parameters were also calculated. The negative values obtained for bonding parameter indicate an ionic character of the bonds from the glass network. Photoluminescence spectra exhibited emissions from samarium ions and revealed the influence of dopant nature on of rare-earth ions emissions. The obtained results indicate that the studied materials are suitable for solid state lasers.