Tagged: publication

Jasti Carbon Nanohoop Research Featured in C&E News

August 2nd, 2012 in Front Page, Jasti, Ramesh, Publications

Professor Ramesh Jasti

Professor Ramesh Jasti

In a July 19 article, C&E News reported on the work of Professor Ramesh Jasti and his Group on carbon nano hoops. Cycloparaphenylenes (CPPs) or nanohoops are made from para-linked benzene rings. Stacking of CPPs could be the basis for preparing useful quantities of pure carbon nanotubes. However, CPPs are so  difficult to make that they are currently sold commercially for about $100 per milligram.  In a remarkable achievement, the Jasti Group have developed a new catalytic method that boosts the yields of eight- and 10-unit nanohoops by two orders of magnitude.  As reported in C&E News, this work has implications for nanoelectronics because armchair nanotubes, the type of carbon nanotubes that would be made by nanohoop stacking, are highly prized as conductive nanowires.

Ramesh Jasti joined the BU faculty in 2009.  The reported work is part of his laboratories goal of utilizing organic synthesis to probe the physics and theory of carbon nanostructures, with the ultimate goal of developing new applications in nanotechnology.  Prior to coming to BU, he was one of the first postdoctoral fellows at the Molecular Foundry—a US Department of Energy nanoscience facility at the Lawrence Berkeley National Laboratory.  As a highly interdisciplinary scientist, Professor Jasti also has appointments in the Materials Science and Engineering Division, as well as the Center for Nanoscience and Nanobiotechnology.

Jasti C&E News Figure

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Reinhard Research Provides Insights into HIV-1

May 14th, 2012 in Front Page, Publications, Reinhard, Björn, Uncategorized

Professor Bjoern Reinhard

Professor Bjoern Reinhard

Recently reported in PNAS, Bjoern Reinhard and his collaborator at the BU Medical School, Dr. Suryaram Gummuluru, have confirmed a unique HIV-1 DC attachment mechanism using lipoparticles with defined surface composition. The  mechanism is dependent on a host-cell–derived ligand, GM3, and is a unique example of pathogen mimicry of host-cell recognition pathways that drive virus capture and dissemination in vivo.   These insights provide the basis for the development of artificial virus nanoparticles with host-derived surface groups that inhibit the HIV-1 trans-dissemination pathway through dendritic cells. The virus parasite uses these dendritic cells to facilitate its dissemination, while avoiding recognition.

Citation: Puryear, et al., “HIV-1 incorporation of host-cell–derived glycosphingolipid GM3 allows for captureby mature dendritic cells”, Proc Natl Acad USA, 2012, 109 (19), 7475-7480.

Reinhard PNAS Fig 1

Gangliosides with α2–3 NeuNAc linkages are important for HIV-1 capture by mDCs. (A) Gag-eGFP VLPs were mock treated or treated with 0.5 units/μL α2–3, 2–6, 2–8 NA. (B) Gag-eGFP VLPs were derived from siRNA-treated HEK293T cells. NT, nontargeting; UGT8, galactosyl transferase; CERT, ceramide transfer protein; UGCG, glucosyltransferases, ST3, GM3 transferase. Capture of VLPs by mDCs was analyzed by FACS (A and B). Data are reported as percentage of eGFP+ mDCs normalized to NT-treated VLPs. (C and D) Ganglioside-deficient HIVLai was derived from HEK293T cells knocked down for NT, UGCG, or ST3. (C) Virions were labeled for p24gag (green) and GM3 (red). Representative fields are shown and the average mean fluorescent intensity (MFI) of GM3 normalized to p24gag ± SD is reported, *P < 0.001, one-way ANOVA with Dunnett’s multiple comparison. (D) Fold decrease of ganglioside-depleted HIVLai capture relative to NT-treated viruses by mDCs is reported. (E) Fold decrease in HIVLaiΔEnv virus capture treated with 0.5 units/μL α2–3, 2–6, 2–8 NA or α2–3-specific NA relative to mock-treated viruses by mDCs is reported. All capture assays represent averaged data from a minimum of three donors, ±SEM, one-sample t test, *P < 0.05, **P < 0.01, ***P < 0.001.

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Reinhard Article Among Ten Most Read in February

April 27th, 2012 in Front Page, Publications, Reinhard, Björn

Professor Bjoern Reinhard

Professor Bjoern Reinhard

The article by Bjoern Reinhard, “Molding the flow of light on the nanoscale: from vortex nanogears to phase-operated plasmonic machinery” (Nanoscale, 2012, 4, 76-90; DOI: 10.1039/C1NR11406A), was amongst the top ten accessed articles from the online version of Nanoscale in February 2012. Launched in 2009, Nanoscale is a new peer reviewed journal publishing experimental and theoretical work across the breadth of nanoscience and nanotechnology.

The Reinhard Group research focuses on new optical materials and their application to interrogate fundamental life processes. They explore the interface between nanotechnology and biological systems. For an overview of current research projects, please visit their group’s website.

Plasmonic nanolens as an internal vortex nanogear transmission. (a) Schematic of the self-similar Ag nanolens proposed in ref 72 (r1 = 45 nm, r2 = 15 nm, r3 = 5 nm, d1 = 9 nm, d2 = 3 nm, ambient index n = 1.0). (b and c) Electric field intensity distribution in the nanolens illuminated on- (b) and off-resonance (c) with the near-field intensity maximum of the nanolens. Far-field (d) and near-field intensity enhancement (e) spectra of the nanolens. (f) The amplitude of the Poynting vector and the phase of the Poynting vector in the x–z plane at the center of the nanolens narrower interparticle gap as a function of wavelength. (g and h) Poynting vector intensity distribution and powerflow around the nanolens off (g) and on (h) the peak intensity wavelength. (i) Schematic of the VNT generated in the nanolens at the peak intensity resonance. Light flux in each nanogear is looped through nanoparticles .

Plasmonic nanolens as an internal vortex nanogear transmission. (a) Schematic of the self-similar Ag nanolens proposed in ref 72 (r1 = 45 nm, r2 = 15 nm, r3 = 5 nm, d1 = 9 nm, d2 = 3 nm, ambient index n = 1.0). (b and c) Electric field intensity distribution in the nanolens illuminated on- (b) and off-resonance (c) with the near-field intensity maximum of the nanolens. Far-field (d) and near-field intensity enhancement (e) spectra of the nanolens. (f) The amplitude of the Poynting vector and the phase of the Poynting vector in the x–z plane at the center of the nanolens narrower interparticle gap as a function of wavelength. (g and h) Poynting vector intensity distribution and powerflow around the nanolens off (g) and on (h) the peak intensity wavelength. (i) Schematic of the VNT generated in the nanolens at the peak intensity resonance. Light flux in each nanogear is looped through nanoparticles .

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Collaborative Research Discovers New Approach in the Treatment of Liver Cancer

April 9th, 2012 in CMLD, Publications, Research, Schaus, Scott

Prof Scott Schaus

Professor Scott Schaus

Until now, there has been no effective, systemic treatment for liver cancer (hepatocellular carcinoma), the fifth most common cancer worldwide. Writing in the Proceedings of the National Academy of Science (PNAS), Professor Scott Schaus (Chemistry) and Professor Ulla Hansen (Biology and Molecular Biology, Cell Biology & Biochemistry) have reported their discovery of a new protein target for chemotherapy in the treatment of liver cancer — the transcription factor LSF. LSF occurs at high levels in the tumor tissue of patients with liver cancer and is known to promote the development of cancer (oncogenesis) in studies using laboratory rodents.

The co-investigators have identified small molecules that effectively inhibit LSF cellular activity, which in turn slows the growth of the cancer. In particular, they found that one such molecule, Factor Quinolinone Inhibitor 1 (FQI1), derived from a lead compound, inhibits the ability of LSF to bind DNA both in extracts (in vitro, as determined by electrophoretic mobility shift assays) and in cells. Consistent with inhibiting LSF activity, FQI1 also eliminates the ability of LSF to turn up transcription. While FQI1 quickly causes cell death in LSF-overexpressing cells, including liver cancer cells, healthy cells are unaffected by the treatment. This phenomenon has been called oncogene addiction, where tumor cells are “addicted” to the activity of an oncogenic factor for their survival, but normal cells can do without it. This characteristic is very encouraging for use
of such compounds clinically.

Structures of LSF inhibitors

Structures of LSF inhibitors

Following in vitro trials, the researchers tested the efficacy of FQI1 in inhibiting liver cancer tumor growth by injecting HCC cell lines into rodent models. FQI1 was observed to significantly inhibit tumor growth with no observable side effects (general tissue cytotoxicity). These dramatic findings support the further development of LSF inhibitors as a promising new chemotherapy treatment for liver cancer.

This work is featured as part of the series, “BU Takes on Cancer,” in BU Today (April 11, 2012).

 

Citation: T.J. Grant, J. A. Bishop, L.M. Christadore, G. Barot, H.G. Chin, S. Woodson, J. Kavouris, A. Siddiq, R. Gedler, X-N. Shen, J. Sherman, T. Meehan, K. Fitzgerald, S. Pradhan, L.A. Briggs, W.H. Andrews, D. Sarkar, S.E. Schaus, and U. Hansen, “Antiproliferative small-molecule inhibitors of transcription factor LSF reveal oncogene addiction to LSF in hepatocellular carcinoma,” Proc. Natl. Acad. Sci. U.S.A., March 20, 2012, Vol. 109, No. 12, 4503-4508.

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Faculty of 1000 Highlights Allen Group Findings

March 14th, 2011 in Allen, Karen, Faculty, Front Page

Professor Karen Allen

Professor Karen Allen

A recent publication in the Journal of the American Chemical Society by Professor Allen and her Research Group, “Engineering Encodable Lanthanide-Binding Tags into Loop Regions of Proteins,” was evaluated in by Professor Gottfried Otting in Faculty of 1000.

It is Professor Otting’s view that, “this paper shows for the first time that a lanthanide-binding peptide can be inserted into the turn connecting two strands of a beta-sheet without affecting the structure and activity of the protein.”

Engineering Encodable Lanthanide-Binding Tags into Loop Regions of Proteins

Engineering Encodable Lanthanide-Binding Tags into Loop Regions of Proteins

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