Background: Novel approaches for synthesis of gold nanoparticles (AuNPs) are of utmost importance owing to its immense applications in diverse fields including catalysis, optics, medical diagnostics and therapeutics. We report on synthesis of AuNPs using Gnidia glauca flower extract (GGFE), its detailed characterization and evaluation of its chemocatalytic potential. Results: Synthesis of AuNPs using GGFE was monitored by UV-Vis spectroscopy and was found to be rapid that completed within 20 min. The concentration of chloroauric acid and temperature was optimized to be 0.7 mM and 50°C respectively. Bioreduced nanoparticles varied in morphology from nanotriangles to nanohexagons majority being spherical. AuNPs were characterized employing transmission electron microscopy, high resolution transmission electron microscopy. Confirmation of elemental gold was carried out by elemental mapping in scanning transmission electron microscopic mode, energy dispersive spectroscopy and X-ray diffraction studies. Spherical particles of size ~10 nm were found in majority. However, particles of larger dimensions were in range between 50-150 nm. The bioreduced AuNPs exhibited remarkable catalytic properties in a reduction reaction of 4-nitrophenol to 4-aminophenol by NaBH₄ in aqueous phase. Conclusion: The elaborate experimental evidences support that GGFE can provide an environmentally benign rapid route for synthesis of AuNPs that can be applied for various purposes. Biogenic AuNPs synthesized using GGFE exhibited excellent chemocatalytic potential.

The objective of the present investigation was to assess the potential of magnesium oxide nanoparticle (MgO NP)-loaded electrospun polycaprolactone (PCL) polymer composites as a bone–soft tissue engineering scaffold. MgO NPs were synthesized using a hydroxide precipitation sol-gel method and characterized using field emission gun–scanning electron microscopy/energy-dispersive x-ray spectroscopy (FEG-SEM/EDS), field emission gun–transmission electron microscopy (FEG-TEM), and x-ray diffraction (XRD) analysis. PCL and MgO–PCL nanocomposite fibers were fabricated using electrospinning with trifluoroethanol as solvent at 19 kV applied voltage and 1.9 ml h ⁻¹ flow rate as optimized process parameters, and were characterized by FEG-TEM, FEG-SEM/EDS, XRD, and differential scanning calorimetry analyses. Characterization studies of as-synthesized nanoparticles revealed diffraction peaks indexed to various crystalline planes peculiar to MgO particles with hexagonal and cubical shape, and 40–60 nm size range. Significant improvement in mechanical properties (tensile strength and elastic modulus) of nanocomposites was observed as compared to neat polymer specimens (fourfold and threefold, respectively), due to uniform dispersion of nanofillers along the polymer fiber length. There was a remarkable bioactivity shown by nanocomposite scaffolds in immersion test, as indicated by formation of surface hydroxyapatite layer by the third day of incubation. MgO-loaded electrospun PCL mats showed enhanced in-vitro biological performance with osteoblast-like MG-63 cells in terms of adhesion, proliferation, and marked differentiation marker activity owing to greater surface roughness, nanotopography, and hydrophilicity facilitating higher protein adsorption. In-vivo subcutaneous implantation study in Sprague Dawley rats revealed initial moderate inflammatory tissue response near implant site at the second week timepoint that subsided later (eighth week) with no adverse effect on vital organ functionalities as seen in histopathological analysis supported by serum biochemical and hematological parameters which did not deviate significantly from normal physiological range, indicating good biocompatibility in-vivo . Thus, MgO–PCL nanocomposite electrospun fibers have potential as an efficient scaffold material for bone–soft tissue engineering applications.

Development of new and effective wound dressing materials continues to be an area of intense research in wound care management. In the present study, we developed nano zinc oxide (nZnO) doped nanofibrous scaffolds of gelatin and PMVE/MA (GPZ) by an electrospinning method for skin tissue engineering and compared it with gelatin and composite scaffolds. Scaffolds were cross-linked with glutaraldehyde vapour to improve scaffold stability. SEM micrographs displayed randomly oriented nanofibers with interconnected pores. TEM and XRD analysis of scaffolds confirmed the presence of nZnO in the GPZ scaffold. Colony forming unit assay and SEM micrographs confirmed the antibacterial activity of nZnO containing scaffold GPZ. Initial biocompatibility testing of scaffolds done with NIH3T3 cells indicated no toxicity of nZnO to mammalian cells. The efficacy of nanofibrous scaffolds for endothelial progenitor cells (EPCs) was assessed in vitro and then their proficiency for wound healing was assessed in vivo by topical application of a matrix with EPCs on wounds in mice. Scaffold GPZ enriched with EPCs exhibited faster and improved wound healing in comparison to other scaffolds. Taking all the results together, our study establishes the proficiency of scaffold GPZ over other scaffolds and it may find its application in skin tissue engineering.