Drug Delivery System Involving Interaction Between Protein or Polypeptide and Hydrophobic Biodegradable Polymer

A drug delivery system for controlled release of a protein or polypeptide comprising a hydrophobic biodegradable polymer and a protein or polypeptide. A physical interaction is present between the polymer and the protein or polypeptide, thus, allowing protection and controlled release of the protein or polypeptide in-vivo. The drug delivery system may be prepared by a polymer precipitation technique or a microsphere technique

Hydrogeomorphic Response to Flooding in Northern Yellowstone National Park

Understanding and predicting flood-induced geomorphic change, and the relative influences of fluvial forces and valley-bottom geometry on system response, are persistent quandaries in geomorphic process studies. We combine field surveys, remote sensing, and hydraulic modeling to assess the hydrogeomorphic effects of historic flooding in northern Yellowstone National Park (YNP) in a variety of channel configurations. We compare impulse, a metric that incorporates a flow duration threshold based on threshold channel theory, grain size, channel-bed slope, and flood depth and stream power estimates with hydrogeomorphic response. Measurements of pre- and post-flood active-channel width change in aerial photos captured geomorphic response associated with deposition-related channel migration while a transect-based metric of bed elevation change from pre- and post-flood DEMs of difference captured erosion-related channel evolution. Hydrogeomorphic response to flooding correlates with fluvial forces in areas that experienced erosion while channel areas of extensive deposition are more closely tied to a decrease in valley-bottom confinement. Bank erosion was greatest in areas immediately downstream of tributaries capable of delivering coarse sediment to the channel that was mobilized during the flood exposing previously protected cutbanks to flood hydraulics. Results indicate that the impulse framework may be a useful tool for investigations of geomorphic change resulting from floods

Mechanical properties of turbine blade alloys in hydrogen at elevated temperatures

The mechanical properties of single crystal turbine blade alloys in a gaseous hydrogen environment were determined. These alloys are proposed for use in space propulsion systems in pure or partial high pressure hydrogen environments at elevated temperatures. Mechanical property tests included: tensile, creep, low fatigue (LCF), and crack growth. Specimens were in both transverse and longitudinal directions relative to the casting solidification direction. Testing was conducted on solid specimens exposed to externally pressurized environments of gaseous hydrogen and hydrogen-enriched steam

Preparation of Biodegradable Microspheres Useful as Carriers for Macromolecules

A method for preparing biodegradable microspheres having a three-dimensional network in which biologically active macromolecular agents are physically entrapped therein. The microsphere is able to degrade and release the macromolecular agent at a controlled rate. The method involves emulsifying a vinyl derivative of a biodegradable hydrophilic polymer, a water-soluble monovinyl monomer and a biologically active macromolecule in water, and copolymerizing the biodegradable hydrophilic polymer and the water-soluble monovinyl monomer such that the biologically active macromolecule is entrapped therein

Biodegradable Microspheres as a Carrier for Macromolecules

A method for preparing biodegradable microspheres having a three-dimensional network in which biologically active macromolecular agents are physically entrapped therein. The microsphere is able to degrade and release the macromolecular agent at a controlled rate. The method involves emulsifying a vinyl derivative of a biodegradable hydrophilic polymer, a water-soluble monovinyl monomer and a biologically active macromolecule in water, and copolymerizing the biodegradable hydrophilic polymer and the water-soluble monovinyl monomer such that the biologically active macromolecule is entrapped therein

Epoxysuccinyl peptide-derived cathepsin B inhibitors: Modulating membrane permeability by conjugation with the C-terminal heptapeptide segment of penetratin

Besides its physiological role in lysosomal protein breakdown, extralysosomal cathepsin B has recently been implicated in apoptotic cell death. Highly specific irreversible cathepsin B inhibitors that are readily cellpermeant should be useful tools to elucidate the effects of cathepsin B in the cytosol. We have covalently functionalised the poorly cellpermeant epoxysuccinyl based cathepsin B inhibitor [RGlyGlyLeu(2S, 3S)tEpsLeuProOH; R=OMe] with the C-terminal heptapeptide segment of penetratin (R=εAhxArg ArgNleLysTrpLysLysNH(2)). The high inhibitory potency and selectivity for cathepsin B versus cathepsin L of the parent compound was not affected by the conjugation with the penetratin heptapeptide. The conjugate was shown to efficiently penetrate into MCF-7 cells as an active inhibitor, thereby circumventing an intracellular activation step that is required by other inhibitors, such as the prodruglike epoxysuccinyl peptides E64d and CA074Me