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.     

Engineering the Protective Oxide Chemistry for Enhanced Corrosion Protection Performance of FeCuCrNiCo-CNT Composite Coatings in 3.5 M NaCl Solution Corrosive Media

Metallurgical and Materials Transactions A - Direct electrodeposition method was used to co-electrodeposit different volume fractions of carbon nanotubes in FeCuCrNiCo high entropy alloy matrix....     

Study of linear and non-linear optical properties of In–Se doped chalcogenide semiconducting glasses

Journal of Materials Science: Materials in Electronics - The present work focuses on the various linear and non-linear optical properties of antimony (Sb) and gallium (Ga) (both 0.1 at.%) doped...     

Investigation of crystal structure,dielectric properties,impedance spectroscopy and magnetic properties of (1-x)BaTiO3 – (x)Ba0.9Ca0.1 Fe12O19 multiferroic composites

Composites having composition (1-x)BaTiO₃?(x)Ba_0.9Ca_0.1Fe₁₂O₁₉ (x = 0.10, 0.20, 0.30) were synthesized by conventional solid-state reaction technique. X-ray diffraction (XRD) was used to examine the phase formation. Rietveld refinement has been done using the FullProf suite which predicted the dual phase symmetry consisting hexagonal (P63/mmc) and tetragonal (P4mm) phases in the prepared composites. The dielectric properties of the obtained composites were investigated at different temperatures as a function of frequency in the range of 100 Hz to 7 MHz. The dielectric constant increases with an increase in Ca doped barium ferrite content. The composites showed usual dielectric dispersive behaviour with increasing frequency. The conduction mechanism and dielectric relaxation were examined by complex impedance spectroscopy (CIS). Nyquist plots of all composites showed two semicircles and their centers lied below the real axis. Magnetic characterization was performed by using a vibrating sample magnetometer (VSM) up to a field of 15 kOe at room temperature. The hysteresis loops reveal the ferromagnetic nature of the composites. The values of saturation magnetization, magnetic moment per formula unit, and corresponding coercivity increases with ferrite content and are maximum at x = 0.3. AC conductivity also increases with ferrite content. The variation of frequency exponent ‘n' of the power-law with temperature suggests that the overlapping large polaron tunneling (OLPT) model is appropriate to explain the mode of conduction in all samples.     

Electrochemical biosensor based on gold coated iron nanoparticles/chitosan composite bound xanthine oxidase for detection of xanthine in fish meat

A xanthine oxidase was immobilized covalently onto chitosan bound gold coated iron nanoparticles (CHIT/Fe-NPs@Au) electrodeposited on the surface of pencil graphite electrode (PGE). A xanthine biosensor was fabricated using XOD/CHIT/Fe-NPs@Au/PGE as working, Ag/AgCl as reference and Pt as auxiliary electrode connected through potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The biosensor exhibited optimum current response within 3 s at pH 7.4, 35 °C and working range 0.1–300 μM, when polarized at 0.5 V vs Ag/AgCl. The sensitivity of the biosensor was 0.001169 mAμ M^–1 cm^–2 with detection limit of 0.1 μM (S/N = 3). The biosensor showed only 25% loss in its initial activity after its 100 uses over 100 days, when stored at 4 °C.