Synthesis of Iron Oxide Magnetic Nanoparticles: Characterization and its Biomedical Application

In the present time, Iron oxide magnetic nanoparticles (IOMNPs) have paid considerable attention due to their exclusive applications in terms of surface-to-volume ratio, superparamagnetism, high surface area, biosensor, bio-separation, catalysis, and biomedicine. Our goal was to synthesis iron oxide magnetic nanoparticles by chemical route technique. The preparation method had a very large effect on the size, shape, and surface chemistry of the magnetic nanoparticles including their applications. The iron chloride solution was prepared by mixing deionized water with iron chloride tetrahydrate. The synthesized powder was characterized by XRD, UV-vis, SEM, FT-IR, DLS, FL, and TGA techniques. Moreover, antibacterial activity was evaluated using the synthesized IOMNPs against Escherichia coli (A), Pseudomonas (B), Enterobacter (C), Staphylococcus aureus (D), and Bacillus subtilis (E) in the concentration of 0.1 mg and 0.5 mg. The results showed that Bacillus subtilis possess a higher antibacterial activity at the concentration of 0.5 mg comparing the other bacterial species. The outcome of this work would contribute to the present understanding of the biomedical application with the obtained size, shape, and synthesized method

Green Synthesis and Characterization of Antibacterial Studies by Iron Oxide Nanoparticles using Carica papaya Leaf Extract

In present years, the synthesis of iron oxide nanoparticles (IONPs) has established excessive potential in biological applications due to their non-toxic role in biological systems, biocompatibility, and biodegradability. Ongoing research efforts focused on IONPs in the expansion of novel technologies as they can be synthesized with surface modification. Here we have studied the antibacterial effects of IONPs which were synthesized effectively through a green synthesis route by using leaf extract of the Carica papaya plant. The formation of IONPs was confirmed by the color change. The crystallinity of IONPs was determined by XRD and the morphology by using SEM, which showed spherical particles of well-dispersed size. The absorption peak was determined by UV–vis spectroscopy at 390 nm. Average particle size distribution was obtained at 56 nm using PSA.  FL spectroscopy indicated the higher emission wavelength by redshift at 641.6 nm. TGA showed that the IONPs are thermally stable up to 200⁰C with no decomposition. The outcome would pave a way for utilizing IONPs for better biomedical application

DNA barcoding and preliminary phylogenetic analysis of few gastropods (Family: Potamididae and Nassariidae) in Vellar estuary mangroves, India by COI and 18S rRNA genes

596-600Class Gastropoda is one of the widely studied invertebrates throughout the globe. But, even now most of the species have been identified only by conventional morphology. DNA barcodes have been greatly useful to delimit the cryptic species. In this study, we have analyzed cytochrome c oxidase I (COI) and 18S rRNA gene sequences from 12 specimens belonging to four species to barcode and examine the molecular variation in gastropods of the Vellar estuary mangroves of Tamil Nadu, India. From the results, it is revealed that, among the four genera, Terebralia, Telescopium, and Cerithidea are closely related than genus Nassarius based on the COI and 18S rRNA gene sequences. The neighbour joining trees also confirmed four distinct clades harbouring four genera. As expected, the within species K2P genetic variation is lesser than between species K2P genetic variation in both the genes. An intensive survey is needed to assess the genetic variation of all gastropods in the manmade Vellar estuary mangroves and nearby natural Pichavaram mangroves with additional molecular markers

Synthesis and Characterization of Silver Nanoparticles from Ashyranthus aspera Extract for Antimicrobial Activity Studies

Development of biologically inspired experimental processes for the synthesis of nanoparticles is evolving into an important branch of nanotechnology. Plant-mediated synthesis of nanomaterials has been increasingly gaining popularity due to its eco-friendly nature and cost-effectiveness. In the present study, we were synthesized silver (Ag) nanoparticles using aqueous extracts of fresh leaves of Ashyranthus aspera medicinal plants as bio-reducing agents. UV-Vis spectrometer used to monitor the reduction of Ag ions and the formation of AgNPs in the medium. UV-Vis spectra and visual observation showed that the color of the fresh leaf extracts of Ashyranthus aspera turned into grayish-brown respectively, after treatment with Ag precursors. XRD and SEM have been used to investigate the morphology of prepared AgNPs. The peaks in the XRD pattern are associated with that of the Face-Centered-Cubic (FCC) form of metallic silver. TGA/DTA results associated with weight loss and exothermic reaction due to the desorption of chemisorbed water. FTIR was performed to identify the functional groups which form a layer covering AgNPs and stabilize the AgNPs in the medium. Moreover, silver nanoparticles using aqueous leaf extracts of Ashyranthus aspera were separately tested for their antibacterial activity against Gram-positive bacteria ( Staphylococcus aureus ) and Gram-negative bacteria ( Enterobacter ). The results showed that the bacterial growth was inhibited by the extracts containing AgNPs Nanoparticles. The biosynthesized nanoparticle was prepared from Ashyranthus aspera leaf extracts exhibits potential applications as broad-spectrum antimicrobial agents

Inhibition of protein ubiquitination by paraquat and 1-methyl-4-phenylpyridinium impairs ubiquitin-dependent protein degradation pathways

Intracytoplasmic inclusions of protein aggregates in dopaminergic cells (Lewy bodies) are the pathological hallmark of Parkinson’s disease (PD). Ubiquitin (Ub), alpha [α]-synuclein, p62/sequestosome 1 and oxidized proteins are major components of Lewy bodies. However, the mechanisms involved in the impairment of misfolded/oxidized protein degradation pathways in PD are still unclear. PD is linked to mitochondrial dysfunction and environmental pesticide exposure. In this work, we evaluated the effect of the pesticide paraquat (PQ) and the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) on Ub-dependent protein degradation pathways. No increase in the accumulation of Ub-bound proteins or aggregates was observed in dopaminergic cells (SK-N-SH) treated with PQ or MPP+, or in mice chronically exposed to PQ. PQ decreased Ub protein content, but not its mRNA transcription. Protein synthesis inhibition with cycloheximide depleted Ub levels and potentiated PQ–induced cell death. Inhibition of proteasomal activity by PQ was found to be a late event in cell death progression, and had no effect on either the toxicity of MPP+ or PQ, or the accumulation of oxidized sulfenylated, sulfonylated (DJ-1/PARK7 and peroxiredoxins) and carbonylated proteins induced by PQ. PQ- and MPP+-induced Ub protein depletion prompted the dimerization/inactivation of the Ub-binding protein p62 that regulates the clearance of ubiquitinated proteins by autophagic. We confirmed that PQ and MPP+ impaired autophagy flux, and that the blockage of autophagy by the overexpression of a dominant-negative form of the autophagy protein 5 (dnAtg5) stimulated their toxicity, but there was no additional effect upon inhibition of the proteasome. PQ induced an increase in the accumulation of α-synuclein in dopaminergic cells and membrane associated foci in yeast cells. Our results demonstrate that inhibition of protein ubiquitination by PQ and MPP+ is involved in the dysfunction of Ub-dependent protein degradation pathways