Showing papers by "Joshua E. Goldberger published in 2012"
TL;DR: A series of self-assembling peptide amphiphile molecules that transform either isolated from molecules or spherical micelles into nanofibers when the pH is slightly reduced in isotonic salt solutions that simulate the acidic extracellular microenvironment of malignant tumor tissue are developed.
Abstract: The creation of smart, self-assembling materials that undergo morphological transitions in response to specific physiological environments can allow for the enhanced accumulation of imaging or drug delivery agents based on differences in diffusion kinetics. Here, we have developed a series of self-assembling peptide amphiphile molecules that transform either isolated from molecules or spherical micelles into nanofibers when the pH is slightly reduced from 7.4 to 6.6, in isotonic salt solutions that simulate the acidic extracellular microenvironment of malignant tumor tissue. This transition is rapid and reversible, indicating the system is in thermodynamic equilibrium. The self-assembly phase diagrams show a single-molecule-to-nanofiber transition with a highly concentration-dependent transition pH. However, addition of a sterically bulky Gd(DO3A) imaging tag on the exterior periphery shifts this self-assembly to more acidic pH values and also induces a spherical micellar morphology at high pH and concent...
173 citations
TL;DR: Quantitative real time reverse transcription polymerase chain reaction and immunohistochemistry analysis for alkaline phosphatase (ALP) and osteopontin expression suggest that these mineralized matrices promote osteogenic differentiation of human mesenchymal stem cells.
59 citations
TL;DR: It is demonstrated that a layered metal chalcogenide lattice, TiS(2), can form a dimensionally reduced crystalline one-dimensional hybrid organic/inorganic TiS (2)(ethylenediamine) framework when synthesized from molecular precursors in solution.
Abstract: Reducing the dimensionality of inorganic lattices allows for the creation of new materials that have unique optoelectronic properties. We demonstrate that a layered metal chalcogenide lattice, TiS2, can form a dimensionally reduced crystalline one-dimensional hybrid organic/inorganic TiS2(ethylenediamine) framework when synthesized from molecular precursors in solution. This solid has strong absorption above 1.70 eV and pronounced emission in the near-IR regime. The energy dependence of the absorption, the near-IR photoluminescence, and electronic band structure calculations confirm that TiS2(ethylenediamine) has a direct band gap.
44 citations
Patent•
09 Apr 2012TL;DR: The peptide amphiphiles of the present invention have increased solubility and reduced nanofiber bundling as mentioned in this paper, which may be used in pharmaceutical applications, for example for in vivo administration to human patients, by increasing biological activity of the compositions toward neurite outgrowth and nerve regeneration.
Abstract: The present invention is directed to peptide amphiphile compounds, compositions and methods of use, wherein nanofiber bundling or epitope aggregation is inhibited. In certain embodiments, the peptide amphiphiles of the present invention have increased solubility and reduced nanofiber bundling. The molecules may be used in pharmaceutical applications, for example for in vivo administration to human patients, by increasing biological activity of the compositions toward neurite outgrowth and nerve regeneration.
11 citations
TL;DR: In this paper, the synthesis of TiS2(en) is described by reaction of TiCl4 with elemental sulfur dissolved in excess en at room temperature in a N2 atmosphere, followed by annealing at 220 °C for 3-5 d in a Parr reactor.
Abstract: TiS2(en) is synthesized by reaction of TiCl4 with elemental sulfur dissolved in excess en at room temperature in a N2 atmosphere, followed by annealing at 220 °C for 3—5 d in a Parr reactor.