Patents by Inventor Birendra K. Patnaik

Birendra K. Patnaik 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).

  • Patent number: 6803069
    Abstract: Disclosed are implantable medical devices with enhanced patency. Expanded polytetrafluoroethylene small caliber vascular grafts coated with polymer bound bio-active agents that exhibit enhanced patency are disclosed. The polymer bound bio-active agents can include anti-thrombogenic agents, antibiotics, antibacterial agents and antiviral agents. Methods of preparing same are also provided.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: October 12, 2004
    Assignee: SciMed Life Systems, Inc.
    Inventors: Birendra K. Patnaik, Horng-Ban Lin, David J. Lentz, Richard J. Zdrahala
  • Patent number: 6713568
    Abstract: Disclosed are bio-active polymer coatings. More particularly, improved bio-active polymer coating are disclosed which include bio-active molecules attached to polymer backbones via spacers having reactive nitrogen groups. Also disclosed are novel reaction schemes for producing same.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: March 30, 2004
    Assignee: SciMed Life Systems, Inc.
    Inventors: Birendra K. Patnaik, Richard J. Zdrahala
  • Patent number: 6338904
    Abstract: Disclosed are bio-active coating compositions for polymeric substrates. In particular, a bio-active coating is described which is the reaction product formed by providing a polymer backbone with at least one free isocyanate group, wherein the isocyanate group is pendant from the polymer backbone. There is further provided a hydrophilic, amine-terminated spacer which has at least one amine group at its first and second ends. One of the amine groups of the spacer is reacted with one or more of the isocyanate groups on the polymer backbone in the presence of an optional catalyst agent. A bio-active agent is then covalently bonded onto an unreacted end of the spacer in the presence of a catalyst. Also disclosed are coating compositions for a substrate and methods of preparing same.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: January 15, 2002
    Assignee: Scimed Life Systems
    Inventors: Birendra K. Patnaik, Richard J. Zdrahala
  • Publication number: 20010044655
    Abstract: Disclosed are implantable medical devices with enhanced patency. Expanded polytetrafluoroethylene small caliber vascular grafts coated with polymer bound bio-active agents that exhibit enhanced patency are disclosed. The polymer bound bio-active agents can include anti-thrombogenic agents, antibiotics, antibacterial agents and antiviral agents. Methods of preparing same are also provided.
    Type: Application
    Filed: June 20, 2001
    Publication date: November 22, 2001
    Applicant: Meadox Medicals, Inc.
    Inventors: Birendra K. Patnaik, Horng-Ban Lin, David J. Lentz, Richard J. Zdrahala
  • Patent number: 6306165
    Abstract: Disclosed are implantable medical devices with enhanced patency. Expanded polytetrafluoroethylene small caliber vascular grafts coated with polymer bound bio-active agents that exhibit enhanced patency are disclosed. The polymer bound bio-active agents can include anti-thrombogenic agents, antibiotics, antibacterial agents and antiviral agents. Methods of preparing same are also provided.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: October 23, 2001
    Assignee: Meadox Medicals
    Inventors: Birendra K. Patnaik, Horng-Ban Lin, David J. Lentz, Richard J. Zdrahala
  • Patent number: 6107416
    Abstract: Disclosed are bio-active coating compositions for polymeric substrates. In particular, a bio-active coating is described which is the reaction product formed by providing a polymer backbone with at least one free isocyanate group, wherein the isocyanate group is pendant from the polymer backbone. There is further provided a hydrophilic, amine-terminated spacer which has at least one amine group at its first and second ends. One of the amine groups of the spacer is reacted with one or more of the isocyanate groups on the polymer backbone in the presence of an optional catalyst agent. A bio-active agent is then covalently bonded onto an unreacted end of the spacer in the presence of a catalyst. Also disclosed are coating compositions for a substrate and methods of preparing same.
    Type: Grant
    Filed: February 1, 1999
    Date of Patent: August 22, 2000
    Assignee: Scimed Life Systems, Inc.
    Inventors: Birendra K. Patnaik, Richard J. Zdrahala
  • Patent number: 6096525
    Abstract: A bio-active material such as heparin, urokinase or streptokinase is bonded via a hydrophilic spacer to a functionality on the surface of a hydrophobic, bio-compatible polymeric substrate to provide a coating of the bio-active material on the surface. The substrate surface is preferably the surface of an implantable medical device such as a vascular graft. An amine and/or hydroxyl functionality on the substrate surface is reacted with an isocyanate group at an end of the hydrophilic spacer to bond the spacer to the substrate, and the bio-active material is reacted with an isocyanate group at another end of the spacer to bond the bio-active material to the spacer. Polymeric substrates include expanded polytetrafluoroethylene and polyethylene terephthalate, and the hydroxyl and/or amine functionality may be provided on the substrate surface by plasma glow discharge. A preferred spacer is an isocyanate end-blocked poly(ethylene oxide).
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: August 1, 2000
    Assignee: Meadox Medicals, Inc.
    Inventor: Birendra K. Patnaik
  • Patent number: 5877263
    Abstract: Disclosed are bio-active coating compositions for polymeric substrates. In particular, a bio-active coating is described which is the reaction product formed by providing a polymer backbone with at least one free isocyanate group, wherein the isocyanate group is pendant from the polymer backbone. There is further provided a hydrophilic, amine-terminated spacer which has at least one amine group at its first and second ends. One of the amine groups of the spacer is reacted with one or more of the isocyanate groups on the polymer backbone in the presence of an optional catalyst agent. A bio-active agent is then covalently bonded onto an unreacted end of the spacer in the presence of a catalyst. Also disclosed are coating compositions for a substrate and methods of preparing same.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: March 2, 1999
    Assignee: Meadox Medicals, Inc.
    Inventors: Birendra K. Patnaik, Richard J. Zdrahala
  • Patent number: 5855618
    Abstract: Disclosed are bio-active polymer coatings. More particularly, improved bio-active polymer coating are disclosed which include bio-active molecules attached to polyurethane backbones via amine-terminated spacers. Also disclosed are novel reaction schemes for producing same.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: January 5, 1999
    Assignee: Meadox Medicals, Inc.
    Inventors: Birendra K. Patnaik, Richard J. Zdrahala
  • Patent number: 5741881
    Abstract: A bio-active coating composition is described which is the reaction product of two different reactions. The first reaction includes reacting a bio-compatible polymer backbone having .alpha.,.beta.-unsaturated carbonyl functionality with a hydrophilic spacer having at least one reactive functional group at its first and second ends. In this reaction, one of the reactive functional groups of the spacer reacts with a .beta.-carbon of the carbonyl functionality to bond the spacer to the polymer backbone. The second reaction includes reacting a bio-active agent with a remaining unreacted reactive functional group of the spacer in the presence of an optional catalyst to covalently bind the bio-active agent to the spacer.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: April 21, 1998
    Assignee: Meadox Medicals, Inc.
    Inventor: Birendra K. Patnaik
  • Patent number: 5728751
    Abstract: A medical device having a bio-active coating is prepared by providing a polymeric substrate having hydroxyl and/or amine functionality on a surface thereof and applying the bio-active coating to the surface. The bio-active coating is the reaction product of two different reactions. The first reaction includes reacting the polymeric substrate with a hydrophilic, isocyanate-terminated spacer having at least one isocyanate group at its first and second ends. The second reaction includes reacting a remaining, unreacted isocyanate-terminated end of the spacer with a bio-active agent to bond the bio-active agent to the spacer.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: March 17, 1998
    Assignee: Meadox Medicals, Inc.
    Inventor: Birendra K. Patnaik
  • Patent number: 5049615
    Abstract: Novel thermoplastic compositions are provided comprising a blend of a polyindane resin and an engineering thermoplastic such as polyphenylene ethers, polysulfones, polycarbonates, polyether ether ketones, polyarylates, polyamides, polyimides and polyphenylene sulfides. Blends of thermoplastic block copolymers with polyindane resins are also provided. These blends provide improved processability with good physical properties including high impact strength and high heat distortion temperature.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: September 17, 1991
    Assignee: Hercules Incorporated
    Inventors: Sung G. Chu, Birendra K. Patnaik, Keith S. Shih
  • Patent number: 4835230
    Abstract: Disclosed is an improved method for making a thermoset polymer wherein a plurality of reactant streams, one of which contains the activator of a metathesis catalyst system combined with a moderator, and a second of which contains the catalyst of the metathesis catalyst system and at least one of which contains dicyclopentadiene are combined to form a reaction mixture, and the reaction mixture is then injected into a mold where polymerization occurs. The improvement comprises adding to the reaction mixture 1-25 mols of a cationic polymerization initiator per 1000 mols of dicyclopentadiene.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: May 30, 1989
    Assignee: Hercules Incorporated
    Inventors: Nitya P. Khasat, Birendra K. Patnaik
  • Patent number: 4382018
    Abstract: A storage stable, improved catalyst is obtained when an aluminum-reduced titanium trichloride catalyst which has been modified by treatment with an electron donor is heated at a temperature and for a period of time sufficient to drive the reaction to completion. In some instances this will involve the removal of gas which has been generated during the modification. In the usual practice a temperature of about 90.degree. C. and a period of about 90 minutes will be employed.
    Type: Grant
    Filed: December 18, 1980
    Date of Patent: May 3, 1983
    Assignee: Dart Industries, Inc.
    Inventors: John L. H. Allan, Birendra K. Patnaik, Agapios Agapiou
  • Patent number: 4351930
    Abstract: The polymerized ethylene content of a copolymer of ethylene and propylene is enhanced without lowering the isotacticity of the copolymer when the polymerization is conducted in the presence of small amounts of butene-1.
    Type: Grant
    Filed: February 5, 1981
    Date of Patent: September 28, 1982
    Assignee: El Paso Polyolefins Company
    Inventor: Birendra K. Patnaik
  • Patent number: 4342856
    Abstract: Propylene polymers of improved melt flow characteristics are obtained in a liquid pool propylene polymerization process carried out in the presence of a magnesium halide supported titanium halide-aluminum trialkyl catalyst system, where prior to its introduction to the polymerization reactor, the magnesium halide supported titanium halide catalyst component is admixed with an aromatic carboxylic acid ester electron donor and the mixture is subsequently introduced into the poymerization zone no later than about 5 days from the time of admixing.
    Type: Grant
    Filed: November 14, 1980
    Date of Patent: August 3, 1982
    Assignee: El Paso Polyolefins Company
    Inventor: Birendra K. Patnaik
  • Patent number: 4308357
    Abstract: A process for the preparation of ethylene-propylene block copolymers at high catalyst productivity rates resulting in polymer products having improved impact strength-polymerized ethylene content relationship.
    Type: Grant
    Filed: October 20, 1980
    Date of Patent: December 29, 1981
    Assignee: El Paso Polyolefins Company
    Inventors: Malcolm J. Kaus, Birendra K. Patnaik
  • Patent number: 4222895
    Abstract: Phosphorus oxytrichloride modified titanium trichloride polymerization catalysts of improved efficiency and/or isotacticity are obtained when the modification reaction is carried out in the presence of methylene chloride.
    Type: Grant
    Filed: May 4, 1979
    Date of Patent: September 16, 1980
    Assignee: Dart Industries Inc.
    Inventors: John L. H. Allan, Birendra K. Patnaik
  • Patent number: 4197387
    Abstract: Phosphorus oxytrichloride modified titanium trichloride polymerization catalysts of improved efficiency and/or isotacticity are obtained when the modification reaction is carried out in the presence of methylene chloride.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: April 8, 1980
    Assignee: Dart Industries Inc.
    Inventors: John L. H. Allan, Birendra K. Patnaik
  • Patent number: 4154702
    Abstract: Phosphorus oxytrichloride modified titanium trichloride polymerization catalysts of improved efficiency and/or isotacticity are obtained when the modification reaction is carried out in the presence of methylene chloride.
    Type: Grant
    Filed: May 22, 1978
    Date of Patent: May 15, 1979
    Assignee: Dart Industries Inc.
    Inventors: John L. H. Allan, Birendra K. Patnaik