70 research outputs found
Abstract LB-232: Nano-CaCO3 as a novel pH-sensitive nanoparticle platform for cancer therapy
No full textIntroduction: The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors and restricts it growth. Methods: We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Biochemical simulations were used to simulate pH changes in vivo using the particle. In vitro and in vivo assays were used to determine pH changes. IV injections of the nanoparticles were implemented in a xenograft model of fibrosarcoma to determine growth changes. Results: Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) dissolution in vivo increases pH asymptotically to 7.4. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3 in tumors increases tumor pHe over time. The persistent neutralization of tumor pHe from nano-CaCO3 induces tumor growth stasis. Conclusions: We have been able to create a novel nanoparticle based on widely existing in vivo components (Calcium and CO3) that safely equilibrates acidic pH of tumors up to normal physiological pH. As expected, this modulation restricts growth of implanted tumors in vivo. Future studies will study the effect of these particles on metastasis, and synergy with other therapeutic modalities. Citation Format: Avik Som, Ramesh Raliya, Walter Akers, Joseph Ippolito, Srikanth Singamaneni, Pratim Biswas, Samuel Achilefu. Nano-CaCO3 as a novel pH-sensitive nanoparticle platform for cancer therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-232
Author Correction: Comparative estimation of nitrogen in urea and its derivative products using TKN, CHNS and hand-held refractometer
No full textBiosynthesis and Characterization of Nanoparticles
No full textBiological synthesis of nanoparticles has emerged as rapidly developing research area in nanotechnology across the globe with various biological entities being employed in production of nanoparticles constantly forming an impute alternative for conventional methods. Simple prokaryotes to complex eukaryotic organisms including higher plants are used for the fabrication of nanoparticles. Techniques such as Dynamic Light Scattering (DLS), Electron Microscopy (TEM, SEM), Atomic Force Microscopy (AFM), X-Ray Photoelectron Spectroscopy (XPS), Powder X-Ray Diffraction (XRD), Energy Dispersive X Ray Spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FTIR) are used to elucidate the morphology, elemental composition and crystal structure of biosynthesized nanoparticles
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No full textTiO2 nanoparticle biosynthesis and its physiological effect on mung bean (Vigna radiata L.)
No full textTiO2 nanoparticle (NPs) biosynthesis is a low cost, ecofriendly approach developed using the fungi Aspergillus flavus TFR 7. To determine whether TiO2 NPs is suitable for nutrient, we conducted a two part study; biosynthesis of TiO2 NP and evaluates their influence on mung bean. The characterized TiO2 NPs were foliar sprayed at 10 mgL−1 concentration on the leaves of 14 days old mung bean plants. A significant improvement was observed in shoot length (17.02%), root length (49.6%), root area (43%), root nodule (67.5%), chlorophyll content (46.4%) and total soluble leaf protein (94%) as a result of TiO2 NPs application. In the rhizosphere microbial population increased by 21.4–48.1% and activity of acid phosphatase (67.3%), alkaline phosphatase (72%), phytase (64%) and dehydrogenase (108.7%) enzyme was observed over control in six weeks old plants owing to application of TiO2 NPs. A possible mechanism has also been hypothesized for TiO2 NPs biosynthesis
Aerosol-synthesized siliceous nanoparticles: impact of morphology and functionalization on biodistribution
No full textPhilipp Diebolder,1 Miguel Vazquez-Pufleau,2 Nilantha Bandara,1 Cedric Mpoy,1 Ramesh Raliya,2 Elijah Thimsen,2 Pratim Biswas,2 Buck E Rogers1 1Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO, USA; 2Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, MO, USA Introduction: Siliceous nanoparticles (NPs) have been extensively studied in nanomedicine due to their high biocompatibility and immense biomedical potential. Although numerous technologies have been developed, the synthesis of siliceous NPs for biomedical applications mainly relies on a few core technologies predominantly intended to produce spherical-shaped NPs. Methods: In this context, the impact of different morphologies of siliceous NPs on biodistribution in vivo is limited. In the present study, we developed a novel technique based on an aerosol silane reactor to produce sintered silicon NPs of similar size but different surface areas due to distinct spherical subunits. Silica-converted particles were functionalized for radiolabeling with copper-64 (64Cu) to systematically analyze their behavior in the passive targeting of A431 tumor xenografts in mice after intravenous injection.Results: While low nonspecific uptake was observed in most organs, the majority of particles were accumulated in the liver, spleen, and lung. Depending on the morphologies and functionalization, significant differences in the uptake profiles of the particles were observed. In terms of tumor uptake, spherical shapes with lower surface areas showed the highest accumulation and tumor-to-blood ratios of all investigated particles.Conclusion: This study highlights the importance of shape and fuctionalization of siliceous NPs on organ and tumor accumulation as significant factors for biomedical applications. Keywords: silicon, silica, human tumor xenograft, PEGylation, 64C
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No full textNot AvailableBiological synthesis of gold nanoparticle is a new approach for environmentally benign protocol in context to green nanotechnology. In present investigation, gold nanoparticles were synthesized using extracellular secrets of fungi Rhizoctonia bataticola TFR-6. Valid characterization techniques employed for biotransformed gold nanoparticles including DLS, TEM, HR-TEM, and AFM for confirmation of size, shape, surface structure and crystalline nature of nanoscale gold particles. The EDX technique was employed for study of the elemental proportion in the biotransformed product. Obtained results confirm the formation of gold nanoparticle in a short period of time and the obtained particles may be useful in biomedical and engineering sector.Not Availabl
Biosynthesis and characterization of zinc, magnesium and titanium nanoparticles: an eco-friendly approach
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No full textNot AvailableDevelopment of reliable and ecofriendly green approach for synthesis of metallic nanoparticles biologically is an important step in the field of application of nanoscience and nanotechnology. The present paper reports the green approach for iron nanoparticle synthesis using Aspergillus oryzae TFR9 using FeCl3 as a precursor metal salt. Valid characterization techniques employed for biosynthesized iron nanoparticles including dynamic light scattering (DLS), transmission electron microscopy (TEM), and high resolution-transmission electron microscopy (HR-TEM) for morphological study. X-ray energy dispersive spectroscopy (EDS) spectrum confirmed the presence of elemental iron signal in high percentage. Apart from ecofriendliness and easy availability, low-cost biomass production will be more advantageous when compared to other chemical methods. Biosynthesis of iron nanoparticles using fungus has greater commercial viability that it may be used in agriculture, biomedicals and engineering sector.Not Availabl
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No full textNot AvailableA novel biological approach for the rapid and cost effective synthesis of silver nanoparticles was
attempted in the limelight of nanotechnology research. The present study demonstrates the synthesis of silver nanoparticle using fungus Aspergillus terreus CZR-1 (NCBI GenBank Accession
No. JF 681300). The fungal isolate was identified on the basis of morphological and molecular
parameters. Transmission electron microscope (TEM) was used for size and shape study that reveal
the spherical structure of monodispersed silver nanoparticle. To ensure the elemental proportion,
electron dispersive spectroscopy (EDS) was performed which confirms the 97 atom% of silver.
The average size of silver nanoparticle was calculated using dynamic light scattering (DLS) was
obtained to be 2.5 nanometer and the polydispersity index (PDI) was 0.195. The crystal structure of
silver nanoparticle was confirmed by high resolution transmission electron microscope (HR-TEM)
and selective area electron diffraction (SAED) pattern.Not Availabl
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