A new route to sol-gel crystalline wollastonite bioceramic

Artificial bone graft materials formed from wollastonite have been extensively used in bone repair because of their high degree of bioactivity and biocompatibility, thereby justifying the development of a protocol for large-scale production. This work reports a novel route for preparing wollastonite via the sol-gel process using bentonite clay as a cheap silica source. The obtained wollastonite was characterized for morphology, elemental composition, phase composition and bioactivity using scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy. Results obtained revealed that wollastonite phase was successfully formed in the material and it showed ability to induce formation of apatite within 0.5 day in biological fluid, an indicator for bone-bonding capability. Overall, the wollastonite prepared from the bentonite clay exhibited properties comparable to that synthesized from commercially obtained sodium metasilicate. Hence, our synthetic route may be useful for commercial-scale preparation of wollastonite

Bioactive glass 45S5 from diatom biosilica

A major draw-back to large scale production of bioactive glasses is the high cost of the standard silica precursor, usually tetraethyl orthosilicate (TEOS). The current study describes a novel sol–gel preparation of 45S5 bioactive glass using diatom biosilica from cultured cells of the diatom, Aulacoseira granulata as substitute to TEOS. The glass formed was characterized using mechanical tester, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Results showed that the glass possessed a compressive strength of 3.75 ± 0.18 and formed carbonated hydroxyapatite (HCA) within 7 days in simulated body fluid (SBF), attributable to good surface chemistry. The performance of the glass was compared with that of those formed using TEOS. Diatom biosilica could be a potential economically friendly starting material for large scale fabrication of bioactive glasses

Drug design and in-silico study of 2-alkoxylatedquinoline-3-carbaldehyde compounds: Inhibitors of Mycobacterium tuberculosis

Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) is a deadly communicable disease that frequently affects the lungs. Current treatment protocols are bedeviled by extensive drug-resistant (XDR) and the evolution of multidrug-resistant (MDR-TB) strains. Virtual in-silico drug discovery tools were used to investigate thirty-two hypothetical 2-alkoxylatedquinoline-3-carbaldehyde compounds for screening against ten different diseases proteins based on drug-likeness, oral bioavailability, pharmacokinetics, global chemical reactivity and their theoretical binding affinities. Their chemical structures were optimized at the density functional theory (DFT) using Becke's three-parameter exchange functional with Lee–Yang–Parr correlation function (B3LYP) and the triple zeta basis set 6–311 in a vacuum using Gaussian 09 W software. Docking study using Pyrx and Discovery studio. Fourteen compounds; 4 - 6, 12 – 14, 19 – 22 and 27–30 complied with the established drug-likeness rules, however, five compounds 12, 13, 27, 28 and 29 exhibited no significant toxicity. Structural activity relationship revealed that shorter (n  5) alkyloxyl substituents at position-2 of the quinoline moiety reduces drug-likeness and increases toxicity. Individually, the binding energies obtained were (-8.9 kcal/ mole) against malaria for compound 12 and (-8.2 kcal/mole) against the diabetes for compound 29, both highest for the ten diseases investigated. Mycobacterium Tuberculosis proteins investigated. Molecular dynamics also confirms that 12 and 27 binds very well in the active pocket of Mycobacterium tuberculosis and calculated total free binding energy from MMPBSA is -97.53 ± 2.47 and -58.62 ± 2.94 kJ/mol respectively. The five lead compounds all had binding energies higher than the reference tuberculosis drugs; Isoniazid and Ethambutanol