Nano LIFE

Joint arthroplasty, specifically total knee arthroplasty (TKA) and total hip arthroplasty (THA), are two of the highest value surgical procedures. Over the last several decades, the materials utilized in these surgeries have improved and increased device longevity. However, with an increased incidence of TKA and THA surgeries in younger patients, it is crucial to make these materials more durable. The addition of nanoparticles is one technology that is being explored for this purpose. This review focuses on the addition of nanoparticles to the various parts of arthroplasty surgery comprising of the metallic, ceramic, or polyethylene components along with the bone cement used for fixation. Carbon additives proved to be the most widely studied, and could potentially reduce stress shielding, improve wear, and enhance the biocompatibility of arthroplasty implants.

Graphene coupling molybdenum-based nanocomposite structures were synthesized by changing the pyrolytic temperature to implement the molybdenum-based optimized microstructure. The structural and surface properties tests showed that the presence of the most variable species and a high proportion of divalent molybdenum on the surface of the material could effectively expose catalytic sites to improve reduction ability of N₂ and inhibited hydrogen evolution reaction. Electrochemical investigations indicated that the Mo-700/rGO nanocomposite exhibited a significantly enhanced electrochemical ammonia synthesis performance. In 0.05M H₂SO₄, the Mo-700/rGO electrode achieved a Faradic efficiency of 12.7% at $-$0.15V versus reversible hydrogen electrode (RHE), and an ammonia yield of 3.93$\mu$g${\text{h}}^{-1}$${\text{cm}}^{-2}$ at $-$0.2V versus RHE.

We report the synthesis of novel quaternary AgInZn₂Te₄ quantum dots (QDs) utilizing organometallic hot injection procedures. By using octadecene and oleylamine as the coordinating solvents and dodecanethiol as the capping ligand, we could arrive at a phosphine-free “green route” for the synthesis. Detailed characterizations were performed using high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-optical emission spectroscopy (ICP-OES), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy, and Photoluminescence (PL) spectroscopy for the structural, compositional, and optical analyses. The nanostructures were spherical, monodisperse, highly crystalline with cubic structure, and having an average diameter of $6.5\pm 0.5$nm with optical features in the visible region.

The tailoring of the coordination environment around a central metal ion by changing ligands in macrocyclic complexes is one of the key approaches to monitoring their functions in various applications. Herein, two macrocyclic complexes of Co(II) transition metal ion, tetra-aza and penta-aza, were synthesized using a condensation reaction between different diamine and dicarboxylic precursors. The prepared complexes were analyzed using various characterization techniques. Further, the electrochemical behavior of both the tetra-aza and penta-aza complexes was investigated using cyclic voltammetry. The Co(II)-penta-aza-complex exhibited a quasi-reversible redox couple for Co(III)/Co(II) transition in the more anodic region as compared to Co(II)-tetra-aza-complex. According to theoretical calculations, the fifth N-coordination transferred a high electron density in the eg-orbital of Co-atom of penta-aza-complex, resulting in an anodic shift in the Co(III)/Co(II) redox potential when compared to the Co(II)-tetra-aza-complex. Furthermore, both complexes were tested for antimicrobial activity against P. aeruginosa, E. coli, S. aureus, and B. subtilis, with the results indicating that Co(II)-penta-aza-complex had higher antimicrobial activity against these bacteria than Co(II)-tetra-aza-complex. This study offers new insight into tailoring the electrochemical and biological features of macrocyclic complexes by tuning the coordination environment around the central metal ion.

Nanoparticles have gained significant importance due to their small size and effective surface area. Green synthesis of nanoparticles has become a significant tool in material synthesis due to its eco-friendly, economical and less time-consuming aspects. Sweet lime (Citrus sinensis) peel has been used for extract preparation and synthesis of AgNPs. Such nanoparticles have been shown to have excellent anti-microbial and detoxification properties. Though a large number of studies have shown synthesis of AgNP from peel and other parts of C. sinensis, there are no reports of AgNP synthesis from oil extracted from seeds. In this study, oil was extracted from C. sinensis seeds by solvent extraction. The extracted oil was used for the synthesis of AgNPs by bottom-up path approach. The synthesized AgNPs were found to be spherical in shape with size ranging from 30nm and above. SEM and TEM showed that they are uniformly dispersed particles with no aggregation. Different concentrations of AgNO₃ (1mM, 3mM and 10mM) showed distinct UV spectra with UV showing sharp peaks for 10mM. XRD characterization showed distinct peaks for AgNP when compared to oil extracted. The synthesized AgNPs in this study showed distinct antibacterial activity against E. coli and S. aureus. The AgNPs showed antifungal activity against Pencillium and Rhizopus. Thus, the synthesized AgNPs could be effective antimicrobial agents that could have potential application in food storage and water detoxification.