Patents by Inventor Robert H. Marchessault

Robert H. Marchessault has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040146855
    Abstract: The present invention features a method for preparing superparamagnetic iron particles by the in situ formation of these particles in a cross-linked starch matrix or by the formation of a superparamagnetic chitosan material. The superparamagnetic materials are formed by mild oxidation of ferrous ion, either entrapped into a cross-linked starch matrix or as a chitosan-Fe(II) complex, with the mild oxidizing agent, nitrate, under alkaline conditions. The present invention further features superparamagnetic iron compositions prepared by the method of the invention. The compositions of the invention are useful for the separation, isolation, identification, or purification of biological materials.
    Type: Application
    Filed: January 27, 2003
    Publication date: July 29, 2004
    Inventors: Robert H. Marchessault, Kirill Shingel, Robert K. Vinson, Didier G. Coquoz
  • Patent number: 6534599
    Abstract: The thermal degradation of the biodegradable bacterial polyesters poly(3-hydroxybutyrate), PHB, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHB/V produces a macromer, especially a 1000-6000 g/mol macromolecule, which contains an unsaturated end group as well as a carboxylic acid end group. The macromers may be polymerized to produce homopolymers and copolymers for different applications in which amphiphilic and biocompatible properties are required, for example, drug delivery systems.
    Type: Grant
    Filed: August 15, 2001
    Date of Patent: March 18, 2003
    Assignee: McGill University
    Inventors: Robert H. Marchessault, Sophie Nguyen, Ga-Er Yu
  • Publication number: 20020042481
    Abstract: The thermal degradation of the biodegradable bacterial polyesters poly(3-hydroxybutyrate), PHB, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHB/V produces a macromer, especially a 1000-6000 g/mol macromolecule, which contains an unsaturated end group as well as a carboxylic acid end group. The macromers may be polymerized to produce homopolymers and copolymers for different applications in which amphiphilic and biocompatible properties are required, for example, drug delivery systems.
    Type: Application
    Filed: August 15, 2001
    Publication date: April 11, 2002
    Inventors: Robert H. Marchessault, Sophie Nguyen, Ga-Er Yu
  • Publication number: 20020037594
    Abstract: A composition comprising a hydrogel matrix and a particulate magnetic material within the matrix may be employed to entrap different agents, including biological entities such as antibodies and antigens, whereby the composition may be employed in immunoseparation and in diagnostic procedures.
    Type: Application
    Filed: April 18, 2001
    Publication date: March 28, 2002
    Inventors: Robert H. Marchessault, Dominic H. Ryan, Virna Veiga
  • Patent number: 6146665
    Abstract: A hydrophilic or lipophilic drug is entrapped or microencapsulated in a polyhydroxyalkanoate homopolymer or copolymer. The homopolymer or copolymer is synthesized in an aqueous medium containing a dissolved hydrophilic drug by in vitro enzyme polymerization of a hydroxyalkanoate Coenzyme A monomer to form microporous granules entrapping the drug. The enzyme may be a polyhydroxyalkanoate synthase, and the monomer may be 3-hydroxybutyryl Coenzyme A or 3-hydroxyvalerate Coenzyme A. The monomer is produced by reaction of a carboxylic acid group of a hydroxyalkanoic acid with a thiol group of Coenzyme A. To microencapsulate a lipophilic drug, droplets of oil containing a lipophilic drug are formed dispersed in an aqueous medium such as in the form of an oil-in-water emulsion. The polyhydroxyalkanoate homopolymer or copolymer is formed in the aqueous medium by the enzyme polymerization to form microcapsules having a core of oil containing the drug. The granules or microcapsules containing the drug may be dried.
    Type: Grant
    Filed: September 9, 1998
    Date of Patent: November 14, 2000
    Assignee: McGill University
    Inventors: Robert H. Marchessault, Dusica Maysinger, Geoffrey Alan Ralph Nobes
  • Patent number: 5451456
    Abstract: A latex comprises a colloidal suspension in water of essentially non-crystalline particles of a polymer or copolymer or .beta.-hydroxyalkanoates, for example .beta.-hydroxybutyrate and .beta.-hydroxyvalerate; the latex may be employed to produce self-supporting filfms or papers which are biodegradable and also readily recyclable.
    Type: Grant
    Filed: August 18, 1992
    Date of Patent: September 19, 1995
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Robert H. Marchessault, Pierre F. LePoutre, Peter E. Wrist
  • Patent number: 5143583
    Abstract: Magnetic paper-forming fibers have a particulate magnetic material incorporated within the fibers, as distinct from between the fibers; this can be achieved by loading the lumens of cellulosic fibers with magnetic particles or by generating magnetic particles in situ in a paper-forming fiber which contains ionic groups effective for ion exchange with ferrous ions; the fibers can be employed to produce single layer or multi-layererd magnetic papers for information storage, security paper applications, paper handling, reprographic applications such as magnetographic printing substrate as well as for speciality uses such as electromagnetic shielding, magnetic separation of antibodies based on selective adsorption.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: September 1, 1992
    Inventors: Robert H. Marchessault, Patrice Rioux, Serge Ricard
  • Patent number: 5122187
    Abstract: Disclosed are hot melt ink compositions suitable for ink jet printing which comprise a colorant, a binder, and a propellant selected from the group consisting of hydrazine; cyclic amines; ureas; carboxylic acids; sulfonic acids; aldehydes; ketones; hydrocarbons; esters; phenols; amides; imides; halocarbons; urethanes; ethers; sulfones; sulfamides; sulfonamides; phosphites; phosphonates; phosphates; alkyl sulfides; alkyl acetates; and sulfur dioxide.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: June 16, 1992
    Assignee: Xerox Corporation
    Inventors: William M. Schwarz, Robert H. Marchessault, Lupu Alexandru, Bernard Henrissat
  • Patent number: 5006170
    Abstract: Disclosed are hot melt ink compositions suitable for ink jet printing which comprise a colorant, a binder, and a propellant selected from the group consisting of hydrazine; cyclic amines; ureas; carboxylic acids; sulfonic acids; aldehydes; ketones; hydrocarbons; esters; phenols; amides; imides; halocarbons; urethanes; ethers; sulfones; sulfamides; sulfonamindes; phosphites; phosphonates; phosphates; alkyl sulfines; alkyl acetates; and sulfur dioxide.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: April 9, 1991
    Assignee: Xerox Corporation
    Inventors: William M. Schwarz, Robert H. Marchessault, Lupu Alexandru, Bernard Henrissat
  • Patent number: 5004664
    Abstract: A toner composition comprised of semicrystalline polyester resin particles, especially polyhydroxyalkanoates, copolymers thereof, or blends, and pigment particles. Processes for the preparation of the semicrystalline polyester resins by ring opening polymerization of a monomer in the presence of a catalyst is also illustrated.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: April 2, 1991
    Assignee: Xerox Corporation
    Inventors: Timothy J. Fuller, Robert H. Marchessault, Terry L. Bluhm