• Biomolecular interaction simulation of supramolecular topologies of organometallic assemblies of Bi(V) with antibiotic Tetracycline Amoxicillin drugs and their experimental activities evaluation

      Kumar, Rajiv; Gulia, Kiran; Chandra, Mina; Aggarwal, Anil K.; Kumar, Anil; Mittan, Sandeep; Mishra, Parashuram (Integrated Science, 2019-09-30)
      Antibiotic drugs i.e. tetracycline and amoxicillin, were used mixed ligands (ML), for designing, architecturing, tailoring and synthesis for synthesis of supramolecular topologies of organometallic assemblies of Bi(V), represented as OMCs‐Bi(V), having O5 set for bonding. Molecular models were proposed as a standard to judge specific interactions in topologies of molecules of ML and derived organometallic assemblies. In OMCs‐Bi(V), on chelation, polarity of Bi(V) get reduced to great extent due to overlap of ML orbital. As a result, delocalization of π‐electrons density clouds get spread over the surface of chelating ring and enhances penetration power of OMCs‐Bi(V) into lipid membranes. This influenced binding with enzyme sites in microorganisms. Some electron set for bonding groups present in ligands moieties display extensive biological activity that may be responsible for increase in hydrophobic character and liposolubility of supramolecular topologies of organometallic of assemblies; ultimately enhanced biological activity of OMCs‐Bi(V).
    • Measuring ZnO nanoparticles available concentrations in contaminated soils using the diffusive gradient in thin-films (DGT) technique

      Pouran, Hamid; Alkasbi, Mohammed; Lahive, Elma; Lofts, Stephen; Zhang, Hao (Elsevier, 2021-06-24)
      A major gap in understanding nanomaterials behaviour in the environment is a lack of reliable tools to measure their available concentrations. In this research we use diffusive gradients in thin films (DGT) for measuring concentrations of zinc oxide nanoparticles (ZNO NPs) in soils. Available nanoparticle concentrations were assessed by difference, using paired DGT devices with and without 1000 MWCO dialysis membranes to exclude NPs. We used ZnO because its toxic effects are accelerated through dissolution to Zn2+. Our test soils had different pH and organic matter (OM) contents, which both affect the dissolution rate of ZnO NPs. Woburn (pH≈6.9, OM≈1.8%) and Lufa (pH≈5.9, OM≈4.2%) soils were spiked to a single concentration of 500 mg of ZnO NPs per 1 kg of soil and the available concentrations of ZnO NPs and dissolved zinc were evaluated in 3, 7, 14, 21, 28, 60, 90, 120, 150 and 180 day intervals using DGT. The results showed that the dissolution of ZnO NPs, as well as the available concentrations of both dissolved and nanoparticulate Zn, were much higher in Lufa soil than in Woburn. This work demonstrates that DGT can be used as a simple yet reliable technique for determining concentrations of ZnO NPs in soils and probing its dissolution kinetics.
    • Nanomaterials theory and applications

      Govindaraman, Loganathan T; Arjunan, Arun; Baroutaji, Ahmad; Robinson, John; Ramadan, Mohamad; Olabi, Abdul-Ghani (Elsevier, 2021-06-01)
      The behavior of matter at the nanoscale alters material properties in comparison to their bulk counterparts. Overall, materials at the nano-range demonstrate modified physical behaviors that offer favorable mechanical, thermodynamic, magnetic, optical, and biomedical properties for a range of applications. As such nanomaterials have their prominence in most scientific domains due to their ability to generate varied responses suitable for specific requirements. However, the implementation of nanomaterials in each situation requires a detailed understanding of the chemical and physical properties of the base materials, control parameters, and methods of fabrication. This paper introduces nanomaterials, their classification and measurement techniques followed by synthesis methods, common properties, applications, and prospects.
    • Sustained PDGF-BB release from PHBHHx loaded nanoparticles in 3D hydrogel/stem cell model

      Dong, Cui-Ling; Webb, William R.; Peng, Qiang; Tang, James Z.; Forsyth, Nicholas R.; Chen, Guo-Qiang; El Haj, Alicia J. (Wiley Periodicals, Inc, 2014-02)
      This study aimed to design a growth factor loaded copolyester of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBHHx) nanoparticles containing 3D collagen matrix to achieve growth factor sustained release for long-term stimulation of human mesenchymal stem cells (hMSCs) proliferation/differentiation for tissue engineer application. Platelet-derived growth factor-BB (PDGF-BB), which is known to enhance hMSCs proliferation in human serum, was selected as a model growth factor, and biodegradable copolyester of PHBHHx was chosen to be the sustained release vehicle. PDGF-BB phospholipid complex encapsulated PHBHHx nanoparticles were fabricated, and their effect on hMSCs proliferation was investigated via assays of CCK-8 and live-dead staining to cells inoculated in 2D tissue culture plates and 3D collagen gel scaffolds, respectively. The resulting spherical PHBHHx nanoparticles were stable in terms of their mean particle size, polydispersity index and zeta potential before and after lyophilization. In vitro study revealed a sustained release of PDGF-BB with a low burst release. Furthermore, sustained released PDGF-BB was revealed to significantly promote hMSCs proliferation in both cell monolayer and cell seeded 3D collagen scaffolds inoculated in serum-free media. Therefore, the 3D collagen matrices with locally sustained release growth factor nanoparticles hold promise to be used for stem cell tissue engineering.