Efficient production and enhanced tumor delivery of engineered extracellular vesicles

Extracellular vesicles (EV), including exosomes and microvesicles, are nano-sized intercellular communication vehicles that participate in a multitude of physiological processes. Due to their biological properties, they are also promising candidates for the systemic delivery of therapeutic compounds, such as cytokines, chemotherapeutic drugs, siRNAs and viral vectors. However, low EV production yield and rapid clearance of administered EV by liver macrophages limit their potential use as therapeutic vehicles. We have used a hollow-fiber bioreactor for the efficient production of bioactive EV bearing the heterodimeric cytokine complex Interleukin-15:Interleukin-15 receptor alpha. Bioreactor culture yielded ∼40-fold more EV per mL conditioned medium, as compared to conventional cell culture. Biophysical analysis and comparative proteomics suggested a more diverse population of EV in the bioreactor preparations, while serum protein contaminants were detectable only in conventional culture EV preparations. We also identified the Scavenger Receptor Class A family (SR-A) as a novel monocyte/macrophage uptake receptor for EV. In vivo blockade of SR-A with dextran sulfate dramatically decreased EV liver clearance in mice, while enhancing tumor accumulation. These findings facilitate development of EV therapeutic methods. © 201

The optical spectroscopy of extraterrestrial molecules

The ongoing quest to identify molecules in the interstellar medium by their electronic spectra in the visible region is reviewed. Identification of molecular absorption is described in the context of the elucidation of the carriers of the unidentified diffuse interstellar bands while molecular emission is discussed with reference to the unidentified Red Rectangle bands. The experimental techniques employed in undertaking studies on the optical spectroscopy of extraterrestrial molecules are described and critiqued in the context of their application.Comment: 21 pages, 9 figures, Invited review Australian Journal of Chemistry, accepted for publicatio

Vacuum ultraviolet Spectroscopy of the carbon molecule C-3 in matrix isolated state: Experiment and theory

Carbon molecules were produced by evaporation of graphite and matrix-isolated in solid neon and argon. Using synchrotron radiation. the absorption spectra of the carbon clusters were recorded from 1100 to 5600 Angstrom, and the fluorescence or phosphorescence spectra were recorded from 1200 to 9000 Angstrom. We observed an intense, broad absorption band system centered at around 1600 Angstrom in neon and 1700 Angstrom in argon. By measuring the excitation spectrum of the (3)Pi(u) --> X (1)Sigma(g)(+) phosphorescence and checking the intensity correlation with the known (1)Pi(u) <-- X (1)Sigma(g)(+) absorption band, we could show that the observed VUV band system is the allowed (1)Sigma(u)(+) <-- X (1)Sigma(g)(+) electronic transition of the C Molecule. At the blue and the red side of the band system, distinct progressions can be observed which most likely correspond to a symmetric stretch of about nu(1) approximate to 1100 cm(-1) and a bending mode of about nu(3) approximate to 550 cm(-1), respectively. In the band center, however, a complicated superposition of several vibrational progressions appears indicating that besides the (1)Sigma(u)(+) state also other states seem to contribute to the absorption. Quantum chemical MR-AQCC calculations suggest that these contributing states are (1)Pi(g) states which are close in energy to the (1)Sigma(u)(+) state and can interact via vibronic coupling, a conjecture supported by preliminary calculations of synthetic spectra in which such coupling was included. Furthermore, the calculations show that the (1)Sigma(u)(+) energy decreases upon bending, leading to a complex landscape of energy surfaces which include avoided crossing type features, and rendering more detailed spectral calculations difficult

Endohedrale und derivatisierte Fullerene sowie kleine Kohlenstoff-Cluster Abschlussbericht

The search for endohedral fullerene compounds in the carbon of cast iron alloys (Levitskii-Dozmerov-method) was carried out in the hope to develop a more effective production method for these technically interesting cage compounds. Although the carbon seems to contain fullerene structures, no significant amounts of extractable empty and endohedral fullerenes could be found. Therefore, this method seems technically uninteresting. Selective functionalzations of C_6_0 were successfully carried out with the help of hydrozirconation. The chemical attack occurred at a 6,6 doublebond of the C_6_0 cage. The derivatives (C_6_0H_2, C_6_0C_5H_5Br, C_6_0C_5H_5OH, C_6_0C_5H_7Br, C_6_0C_5H_7OH, C_6_0C_5H_6) could be characterized completely. To study the first steps of fullerene-formation, the small molecules of carbon vapor C_n (with n=1,2,3) were isolated in cryogenic matrices of argon-ice and studied by optical spectroscopy. Upon thermal annealing of the matrices, the molecules diffuse within the matrix and combine to larger units. The growth of molecules could be followed spectroscopically up to a range C_n (with n,15). However, the assignment of the spectra to specific clusters is often difficult because of the limited knowledge of the carbon molecular spectra. (orig.)Available from TIB Hannover: F95B2005+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Vacuum ultraviolet Spectroscopy of the carbon molecule C-3 in matrix isolated state: Experiment and theory

Carbon molecules were produced by evaporation of graphite and matrix-isolated in solid neon and argon. Using synchrotron radiation. the absorption spectra of the carbon clusters were recorded from 1100 to 5600 Angstrom, and the fluorescence or phosphorescence spectra were recorded from 1200 to 9000 Angstrom. We observed an intense, broad absorption band system centered at around 1600 Angstrom in neon and 1700 Angstrom in argon. By measuring the excitation spectrum of the (3)Pi(u) --> X (1)Sigma(g)(+) phosphorescence and checking the intensity correlation with the known (1)Pi(u) <-- X (1)Sigma(g)(+) absorption band, we could show that the observed VUV band system is the allowed (1)Sigma(u)(+) <-- X (1)Sigma(g)(+) electronic transition of the C Molecule. At the blue and the red side of the band system, distinct progressions can be observed which most likely correspond to a symmetric stretch of about nu(1) approximate to 1100 cm(-1) and a bending mode of about nu(3) approximate to 550 cm(-1), respectively. In the band center, however, a complicated superposition of several vibrational progressions appears indicating that besides the (1)Sigma(u)(+) state also other states seem to contribute to the absorption. Quantum chemical MR-AQCC calculations suggest that these contributing states are (1)Pi(g) states which are close in energy to the (1)Sigma(u)(+) state and can interact via vibronic coupling, a conjecture supported by preliminary calculations of synthetic spectra in which such coupling was included. Furthermore, the calculations show that the (1)Sigma(u)(+) energy decreases upon bending, leading to a complex landscape of energy surfaces which include avoided crossing type features, and rendering more detailed spectral calculations difficult