16 research outputs found
Biodegradable Nanocarriers Resembling Extracellular Vesicles Deliver Genetic Material with the Highest Efficiency to Various Cell Types
Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for coâtransfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 Ă 10â4 pmol of siRNA, and 1 Ă 10â3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo
Fermi Large Area Telescope Observations of Gamma-ray Pulsars PSR J1057-5226, J1709-4429, and J1952+3252
The Fermi Large Area Telescope (LAT) data have confirmed the pulsed emission
from all six high-confidence gamma-ray pulsars previously known from the EGRET
observations. We report results obtained from the analysis of 13 months of LAT
data for three of these pulsars (PSR J1057-5226, PSR J1709-4429, and PSR
J1952+3252) each of which had some unique feature among the EGRET pulsars. The
excellent sensitivity of LAT allows more detailed analysis of the evolution of
the pulse profile with energy and also of the variation of the spectral shape
with phase. We measure the cutoff energy of the pulsed emission from these
pulsars for the first time and provide a more complete picture of the emission
mechanism. The results confirm some, but not all, of the features seen in the
EGRET data.Comment: Accepted for publication in ApJ. 45 pages, 12 figures, 11 tables.
Corresponding authors: O. Celik, F. Gargano, T. Reposeur, D.J. Thompso
Fermi Large Area Telescope Observations of the Crab Pulsar and Nebula
We report on gamma-ray observations of the Crab Pulsar and Nebula using 8
months of survey data with the Fermi Large Area Telescope (LAT). The high
quality light curve obtained using the ephemeris provided by the Nancay and
Jodrell Bank radio telescopes shows two main peaks stable in phase with energy.
The first gamma-ray peak leads the radio main pulse by (281 \pm 12 \pm 21) mus,
giving new constraints on the production site of non-thermal emission in pulsar
magnetospheres. The improved sensitivity and the unprecedented statistics
afforded by the LAT enable precise measurement of the Crab Pulsar spectral
parameters: cut-off energy at E_c = (5.8 \pm 0.5 \pm 1.2) GeV, spectral index
of Gamma = (1.97 \pm 0.02 \pm 0.06) and integral photon flux above 100 MeV of
(2.09 \pm 0.03 \pm 0.18) x 10^{-6} cm^{-2} s^{-1}. The first errors represent
the statistical error on the fit parameters, while the second ones are the
systematic uncertainties. Pulsed gamma-ray photons are observed up to ~ 20 GeV
which precludes emission near the stellar surface, below altitudes of around 4
to 5 stellar radii in phase intervals encompassing the two main peaks. The
spectrum of the nebula in the energy range 100 MeV - 300 GeV is well described
by the sum of two power-laws of indices Gamma_{sync} = (3.99 \pm 0.12 \pm 0.08)
and Gamma_{IC} = (1.64 \pm 0.05 \pm 0.07), corresponding to the falling edge of
the synchrotron and the rising edge of the inverse Compton components,
respectively. This latter, which links up naturally with the spectral data
points of Cherenkov experiments, is well reproduced via inverse Compton
scattering from standard Magnetohydrodynamics (MHD) nebula models, and does not
require any additional radiation mechanism.Comment: 17 pages, 9 figures, Accepted for publications in Astrophysical
Journa
Fermi-LAT Search for Pulsar Wind Nebulae around gamma-ray Pulsars
The high sensitivity of the Fermi-LAT (Large Area Telescope) offers the first
opportunity to study faint and extended GeV sources such as pulsar wind nebulae
(PWNe). After one year of observation the LAT detected and identified three
pulsar wind nebulae: the Crab Nebula, Vela-X and the PWN inside MSH 15-52. In
the meantime, the list of LAT detected pulsars increased steadily. These
pulsars are characterized by high energy loss rates from ~3 \times 10^{33} erg
s to 5 \times 10 erg s and are therefore likely to power a
PWN. This paper summarizes the search for PWNe in the off-pulse windows of 54
LAT-detected pulsars using 16 months of survey observations. Ten sources show
significant emission, seven of these likely being of magnetospheric origin. The
detection of significant emission in the off-pulse interval offers new
constraints on the gamma-ray emitting regions in pulsar magnetospheres. The
three other sources with significant emission are the Crab Nebula, Vela-X and a
new pulsar wind nebula candidate associated with the LAT pulsar PSR J1023-5746,
coincident with the TeV source HESS J1023-575. We further explore the
association between the H.E.S.S. and the Fermi source by modeling its spectral
energy distribution. Flux upper limits derived for the 44 remaining sources are
used to provide new constraints on famous PWNe that have been detected at keV
and/or TeV energies.Comment: Accepted for publication in Astrophysical Journal, 42 pages, 17
figure
Targeted Therapy for Glomerulonephritis Using Arterial Delivery of Encapsulated Etanercept
Complex immunosuppressive therapy is prescribed in medical practice to patients with glomerulonephritis to help them overcome symptoms and prevent chronic renal failure. Such an approach requires long-term systemic administration of strong medications, which causes severe side effects. This work shows the efficiency of polymer capsule accumulation (2.8 ± 0.4 ”m) containing labeled etanercept (100 Όg per dose) in the kidneys of mice. The comparison of injection into the renal artery and tail vein shows the significant superiority of the intra-arterial administration strategy. The etanercept retention rate of 18% and 8% ID in kidneys was found 1 min and 1 h after injection, respectively. The capsules were predominantly localized in the glomeruli after injection in mice using a model of acute glomerulonephritis. Histological analysis confirmed a significant therapeutic effect only in animals with intra-arterial administration of microcapsules with etanercept. The proposed strategy combines endovascular surgery and the use of polymer microcapsules containing a high molecular weight drug that can be successfully applied to treat a wide range of kidney diseases associated with glomerular pathology
Polymeric micro- and nano-carriers as a universal platform for delivery of biologically active substances to therapeutically cell populations
Correction to âRadiolabeling Strategies of Micron- and Submicron-Sized CoreâShell Carriers for In Vivo
Biodegradable nanocarriers resembling extracellular vesicles deliver genetic material with the highest efficiency to various cell types
Abstract
Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for coâtransfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 Ă 10â4 pmol of siRNA, and 1 Ă 10â3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo
Correction to âDevelopment of Nanocarrier-Based Radionuclide and Photothermal Therapy in Combination with Chemotherapy in Melanoma Cancer Treatmentâ
Correction to âDevelopment
of Nanocarrier-Based
Radionuclide and Photothermal Therapy in Combination with Chemotherapy
in Melanoma Cancer Treatment