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The purpose of this research was to determine the efficacy of iron oxide nanoparticles (Fe3O4-NPs) using microalgal products as a plant growth stimulant and antifungal agent. The work was conducted with the phyco-synthesis and characterization of Fe3O4-NPs using 0.1 M ferric/ferrous chloride solution (2:1 ratio; 65 °C) with aqueous extract of the green microalga Chlorella K01. Protein, carbohydrate and polyphenol contents of Chlorella K01 extract were measured. The synthesized microalgal Fe3O4-NPs made a significant contribution to the germination and vigor index of rice, maize, mustard, green grams, and watermelons. Fe3O4-NPs also exhibited antifungal activity against Fusarium oxysporum, Fusarium tricinctum, Fusarium maniliforme, Rhizoctonia solani, and Phythium sp. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analysers (PSA), and zeta potential (ZP) measurements were used to characterize these green fabricated magnetite NPs. FTIR analysis showed that the synergy of microalgal proteins, carbohydrtates and polyphenols is responsible for the biofabrication of iron nanoparticles. A spheroid dispersion of biosynthesized Fe3O4-NPs with an average diameter of 76.5 nm was produced in the synthetic process. [ABSTRACT FROM AUTHOR]

Growing resistance in malarial parasites, particularly in Plasmodium falciparum needs a serious search for the discovery of novel drug targets. Inosine monophosphate dehydrogenase (IMPDH) is an important target for antimalarial drug discovery process in P. falciparum for the treatment of malaria. In the absence of x-ray crystal structure of this enzyme, homology modeling proved to be a reasonable alternate to study substrate binding mechanisms of this enzyme. In this study, a 3-D homology model for P. falciparum IMPDH was constructed taking human IMPDH (PDB code 1NF7 ) as template. Furthermore, an in-silico combinatorial library of ribavirin (RVP) derivatives (1347 molecules) was designed and virtually screened for ligands having selectively greater binding affinity with Plasmodium falciparum IMPDH relative to human IMPDH II. A total of five Ribavirin derivatives were identified as having greater binding affinity (−126 to −108 Kcal/mol and −9.4 to −8.6 Kcal/mol) with Plasmodium falciparum IMPDH. These five inhibitors should be used as selective and potent for Plasmodium falciparum IMPDH. Such type of study will provide information to synthetic medicinal chemist to enhance the potential of compounds (RVP derivatives) as chemotherapeutic agents to fight against the increasing burden of malarial infections. [ABSTRACT FROM AUTHOR]

Antibiotic-resistant bacterial strains have been continuously increasing and becoming a supreme threat to public health globally. The nanoparticle-based photothermal treatment has emerged as a powerful tool to combat toxic bacteria. Photothermal agents (PTAs) with cost-effective and high photothermal conversion efficiency are highly desirable. Herein, we unite the green process for delamination of V 2 AlC to produce a high yield mass of two-dimensional (2D) V 2 C nanosheets (NSs) by using algae extracts and demonstrate their high antibacterial efficiency. The resultant V 2 C NSs present decent structural reliability and intrinsic antibacterial ability. Powerful near-infrared (NIR) absorption and extraordinary photothermal conversion proficiency make it a good PTA for the photothermal treatment of bacteria. The antibacterial efficiency evaluation indicated that V 2 C NSs could effectively kill both Gram-positive S. aureus and Gram-negative E. coli . About 99.5% of both types of bacteria could be killed with low-dose of V 2 C NSs suspension (40 μg/mL) with 5 min NIR irradiation due to the intrinsic antibacterial ability and photothermal effect of V 2 C NSs, which is much higher than previous reports on Ta 4 C 3 , Ti 3 C 2 , MoSe 2 , and Nb 2 C. This work expands the application of MXene V 2 C NSs for rapid bacteria-killing and would gain promising attention for applications in the sterilization industry.

The two-dimensional (2D) vanadium carbide (V 2 C) MXene has shown great potential as a photothermal agent (PTA) for photothermal therapy (PTT). However, the use of V 2 C in PTT is limited by the harsh synthesis condition and low photothermal conversion efficiency (PTCE). Herein, we report a completely different green delamination method using algae extraction to intercalate and delaminate V 2 AlC to produce mass V 2 C nanosheets (NSs) with a high yield (90 %). The resulting V 2 C NSs demonstrated good structural integrity and remarkably high absorption in near infrared (NIR) region with a PTCE as high as 48 %. Systemic in vitro and in vivo studies demonstrate that the V 2 C NSs can serve as efficient PTA for photoacoustic (PA) and magnetic resonance imaging (MRI)-guided PTT of cancer. This work provides a cost-effective, environment-friendly, and high-yielding disassembly approach of MAX, opening a new avenue to develop MXenes with desirable properties for a myriad of applications., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Bimetallic nanoparticles have received considerable attention owing to synergistic effect and their multifunctionality. Herein, new multifunctional Pd@Au bimetallic nanoplates decorated hollow mesoporous MnO 2 nanoplates (H-MnO 2 ) are demonstrated for achieving not only nucleus-targeted NIR-II photothermal therapy (PTT), but also tumor microenvironment (TME) hypoxia relief enhanced photodynamic therapy (PDT). The Pd@Au nanoplates present a photothermal conversion efficiency (PTCE) as high as 56.9%, superior to those PTAs activated in the NIR-II region such as Cu 9 S 5 nanoparticles (37%), Cu 3 BiS 3 nanorods (40.7%), and Au/Cu 2- x S nanocrystals (43.2%). They further functionalize with transactivator of transcription (TAT) moiety for cell nuclear-targeting and biodegradable hollow mesoporous MnO 2 (≈100 nm) loaded with photosensitizer Ce6 (TAT-Pd@Au/Ce6/PAH/H-MnO 2 ) to construct a hierarchical targeting nanoplatform. The as-made TAT-Pd@Au/Ce6/PAH/H-MnO 2 demonstrates good premature renal clearance escape ability and increased tumor tissue accumulation. It can be degraded in acidic TME and generate O 2 by reacting to endogenous H 2 O 2 to relieve the hypoxia for enhanced PDT, while the released small TAT-Pd@Au nanoplates can effectively enter into the nucleus to mediate PTT. As a result, a remarkable therapeutic effect is achieved owing to the synergistic PTT/PDT therapy. This hierarchical targeting, TME-responsive, cytoplasm hypoxia relief PDT, and nuclear NIR-II PTT synergistic therapy can pave a new avenue for nanomaterials-based cancer therapy., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ionic silver is a potential hazard to aquatic life forms because of the increasing usage of silver based materials. The need for developing a sustainable and ecofriendly process to minimize the toxic effects of the free ions burden is now a scientific consensus. Therefore, we report the latest results in cyanobacterium Leptolyngbya JSC-1 investigating the tolerance towards toxic doses of silver, its extracellular biomineralization and silver nano-deposits formation inside the cells, and speculate about potential environmental impacts. In this study, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) analysis reveal the extracellular biomineralization of soluble silver (1-100 μM) into corresponding nanoparticles (50-100 nm in diameter) by JSC-1, while X-ray photoelectron spectroscopy (XPS) examination divulged the presence of both Ag + and Ag 0 in extracellularly biomineralized silver, depicting a mixture of both Ag x O and elemental Ag. The scanning transmission electron microscopy (STEM), EDS and elemental mapping visualized the formation of intracellular silver nanoparticles. Moreover, this feature of silver tolerance in JSC-1 was further exploited and a novel protocol was developed for isolation and maintenance of axenic culture of this filamentous cyanobacterium. Consequently, this capability of silver biomineralization by JSC-1, both extra- and intra-cellularly might be useful for modeling the Ag resistance mechanism in cyanobacteria and also might be a sustainable alternative for heavy metals bioremediation in aquatic environments., (Copyright © 2018 Elsevier Ltd. All rights reserved.)