Novel and simple approach using synthesized nickel nanoparticles to control blood-sucking parasites.

The present study was on assessment of the anti-parasitic activities of nickel nanoparticles (Ni NPs) against the larvae of cattle ticks Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum (a.) anatolicum (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, Culex quinquefasciatus and Culex gelidus (Diptera: Culicidae). The metallic Ni NPs were synthesized by polyol process from Ni-hydrazine as precursor and Tween 80 as both the medium and the stabilizing reagent. The synthesized Ni NPs were characterized by Fourier transform infrared (FTIR) spectroscopy analysis which indicated the presence of Ni NPs. Synthesized Ni NPs showed the X-ray diffraction (XRD) peaks at 42.76°, 53.40°, and 76.44°, identified as 111, 220, and 200 reflections, respectively. Scanning electron microscopy (SEM) analysis of the synthesized Ni NPs clearly showed that the Ni NPs were spherical in shape with an average size of 150 nm. The Ni NPs showed maximum activity against the larvae of R. (B.) microplus, H. a. anatolicum, A. subpictus, C. quinquefasciatus and C. gelidus with LC(50) values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r(2) values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC(50) values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r(2) values of 0.988, 0.986, 0.989, 0.944 and 0.978, respectively. The findings revealed that synthesized Ni NPs possess excellent larvicidal parasitic activity. To the best of our knowledge, this is the first report on larvicidal activity of blood feeding parasites using synthesized Ni NPs.

Gelatin nanocarrier enables efficient delivery and phototoxicity of hypocrellin B against a mice tumour model.

Nanoparticles formulated from biodegradable and natural polymer gelatin, were investigated for their potential to enable efficient delivery and enhanced efficacy of a well-known photodynamic agent, Hypocrellin B (HB). The HB-loaded poly(ethylene glycol) modified gelatin nanoparticles (HB-PEG-GNP) possessed near-spherical shape, with particle size in the range of 292 +/- 42 nm, and demonstrated characteristic optical properties for photodynamic therapy (PDT). Photophysical studies of the HB-PEG-GNP demonstrated photogeneration of reactive oxygen species (ROS). The nanoparticles were tested for cellular uptake in vitro, on Daltons' Lymphoma Ascites (DLA) cells and demonstrated dose dependent phototoxicity upon visible light treatment. HB-PEG-GNP induced mitochondrial damage, as investigated by JC-1 staining, leading to apoptotic cell death. Biodistribution measurements revealed that nanoformulation reduces liver uptake of HB-PEG-GNP and increases tumour uptake with time. In vivo PDT studies in solid tumour bearing mice showed markedly significant regression (38.5 +/- 2.2%, p < 0.05) for HB-PEG-GNP treated mice in contrast to those treated with free HB (29.36 +/- 1.62%). The present study reveals gelatin nanocarrier to be an effective drug delivery system for enhancement of therapeutic efficacy of the PDT agent, HB.

Copper nanoparticles synthesized by polyol process used to control hematophagous parasites.

The present study was based on assessments of the anti-parasitic activities of the hematophagous (blood feeding) larvae of malaria vector, Anopheles subpictus Grassi, filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae), and the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae). The metallic copper nanoparticles (Cu NPs) synthesized by polyol process from copper acetate as precursor and Tween 80 were used as both the medium and the stabilizing reagent. The efficacy of synthesized Cu NPs was tested against the larvae of blood-sucking parasites. UV-vis spectra characterization was performed, and peak was observed at 575 nm, which is the characteristic to the surface plasmon bond of Cu NPs. The strong surface plasmon absorption band observed at 575 nm may be due to the formation of non-oxidized Cu NPs. X-ray diffraction (XRD) spectral data showed concentric rings corresponding to the 26.79 (111), 34.52 (200), and 70.40 (220) reflections. XRD spectrum of the copper nanoparticles exhibited 2θ values corresponding to the copper nanocrystal. No peaks of impurities are observed in XRD data. The scanning electron micrograph (SEM) showed structures of irregular polygonal, cylindrical shape, and the size range was found to be 35-80 nm. The size of the Cu NPs was measured by atomic force microscope (AFM) in non-contact mode. For imaging by AFM, the sample was suspended in acetone and spins coated on a silicon wafer. The line profile image was drawn by the XEI software and the horizontal line at 6 µm on a 2D AFM image. Research has demonstrated that metallic nanoparticles produce toxicity in aquatic organisms that is due largely to effects of particulates as opposed to release of dissolved ions. Copper acetate solution tested against the parasite larvae exposed to varying concentrations and the larval mortality was observed for 24 h. The larval percent mortality observed in synthesized Cu NPs were 36, 49, 75, 93,100; 32, 53, 63, 73, and 100 and 36, 47, 69, 88, 100 at 0.5, 1.0, 2.0, 4.0, and 8.0 mg/L against A. subpictus, C. quinquefasciatus and R. microplus, respectively. The larval percent mortality shown in copper acetate solution were 16, 45, 57, 66 and 100, 37, 58, 83, 87, and 100 and 41, 59, 79, 100, and 100 at 10, 20, 30, 40, and 50 mg/L against A. subpictus, C. quinquefasciatus, and R. microplus, respectively. The maximum efficacy was observed in Cu NPs and copper acetate solution against the larvae of A. subpictus, C. quinquefasciatus, and R. microplus with LC(50) and r (2) values of 0.95 and 23.47, 1.01 and 15.24, and 1.06 and 14.14 mg/L with r (2) = 0.766; 0.957 and 0.908; 0.946; and 0.816 and 0.945, respectively. The control (distilled water) showed nil mortality in the concurrent assay. The chi-square value was significant at p ≤ 0.05 level. This is the first report on anti-parasitic activity of the synthesized Cu NPs and copper acetate solution.

Selective toxicity of ZnO nanoparticles toward Gram-positive bacteria and cancer cells by apoptosis through lipid peroxidation.

Nanoparticles are increasingly recognized for their utility in biological applications including nanomedicine. The present study investigated the toxicity of zinc oxide (ZnO) nanoparticles toward prokaryotic and eukaryotic cells. Cytotoxicity of ZnO to mammalian cells was studied using human myeloblastic leukemia cells (HL60) and normal peripheral blood mononuclear cells (PBMCs). Antibacterial activity of ZnO was also tested against the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, as well as the Gram-positive bacterium Staphylococcus aureus, and the effect was more pronounced with the Gram-positive than the Gram-negative bacteria. ZnO nanoparticles exhibited a preferential ability to kill cancerous HL60 cells as compared with normal PBMCs. The nanoparticles enhanced ultrasound-induced lipid peroxidation in the liposomal membrane. The work suggested two mechanisms underlying the toxicity of ZnO: (i) involvement of the generation of reactive oxygen species (ROS) and (ii) induction of apoptosis. The work also revealed potential utility of ZnO nanoparticles in the treatment of cancer, for their selective toxicity to cancer cells. FROM THE CLINICAL EDITOR: The toxicity of zinc oxide to bacteria was related to the generation of reactive oxygen species and to the induction of apoptosis. Interestingly, these effects were differentially greater in human myeloblastic leukemia cells (HL60) than normal peripheral blood mononuclear cells.

Enhanced photodynamic efficacy and efficient delivery of Rose Bengal using nanostructured poly(amidoamine) dendrimers: potential application in photodynamic therapy of cancer.

Photodynamic therapy (PDT) is a promising treatment methodology whereby diseased cells and tissues are destroyed by reactive oxygen species (ROS) by using a combination of light and photosensitizers (PS). The medical application of Rose Bengal (RB), photosensitizer with very good ROS generation capability, is limited due to its intrinsic toxicity and insufficient lipophilicity. In this report, we evaluate the potential of polyamidoamine (PAMAM) dendrimers in delivering RB and its phototoxic efficiency towards a model cancer cell line. The spherical, nanoscaled dendrimers could efficiently encapsulate RB and showed characteristic spectral responses. The controlled release property of dendrimer-RB formulation was clearly evident from the in vitro drug release study. ROS generation was confirmed in dendrimer-RB system upon white light illumination. Photosensitization of Dalton's Lymphoma Ascite (DLA) cells incubated with dendrimer-RB formulation caused remarkable photocytotoxicity. Importantly, the use of dendrimer-based delivery system reduced the dark toxicity of RB.