Patents by Inventor Shmuel Zalipsky

Shmuel Zalipsky 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).

  • Process for preparing active carbonates of polyalkylene oxides for modification of polypeptides
    Patent number: 5808096
    Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: September 15, 1998
    Assignee: Enzon, Inc.
    Inventor: Shmuel Zalipsky
  • Active carbonates of polyalkylene oxides for modification of polypeptides
    Patent number: 5612460
    Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: March 18, 1997
    Assignee: Enzon, Inc.
    Inventor: Shmuel Zalipsky
  • Chemically modified hemoglobin as an effective, stable, non-immunogenic red blood cell substitute
    Patent number: 5386014
    Abstract: The present invention relates to chemically modified hemoglobin produced by a novel and efficient method in which stroma-free hemoglobin is first effectively deoxygenated and reduced and then conjugated with a polyalkylene oxide such as polyethylene glycol (PEG) under conditions which maintain the structural integrity of the heme oxygen binding site. In specific, preferred embodiments of the invention, the deoxygenation and reduction is performed under an inert atmosphere by the amino acid cysteine. In additional specific, preferred embodiments, the structural integrity of the heme oxygen binding site is maintained by a high anionic concentration in the reaction mixture. In further preferred specific emodiments of the invention, the polyalkylene oxide is polyethylene glycol; in still further preferred specific embodiments of the invention, the polyalkylene oxide is linked to hemoglobin via a urethane (carbamate) linkage.
    Type: Grant
    Filed: May 22, 1992
    Date of Patent: January 31, 1995
    Assignee: Enzon, Inc.
    Inventors: Kwang Nho, Shmuel Zalipsky, Frank Davis
  • Active carbonates of polyalkylene oxides for modification of polypeptides
    Patent number: 5324844
    Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.
    Type: Grant
    Filed: January 8, 1992
    Date of Patent: June 28, 1994
    Assignee: Enzon, Inc.
    Inventor: Shmuel Zalipsky
  • Chemically modified hemoglobin as an effective, stable non-immunogenic red blood cell substitute
    Patent number: 5234903
    Abstract: The present invention relates to chemically modified hemoglobin produced by a novel and efficient method in which stroma-free hemoglobin is first effectively deoxygenated and reduced and then conjugated with a polyalkylene oxide such as polyethylene glycol (PEG) under conditions which maintain the structural integrity of the heme oxygen binding site. In specific, preferred embodiments of the invention, the deoxygenation and reduction is performed under an inert atmosphere by the amino acid cysteine. In additional specific, preferred embodiments, the structural integrity of the heme oxygen binding site is maintained by a high anionic concentration in the reaction mixture. In further preferred specific embodiments of the invention, the polyalkylene oxide is polyethylene glycol; in still further preferred specific embodiments of the invention, the polyalkylene oxide is linked to hemoglobin via a urethane (carbamate) linkage.
    Type: Grant
    Filed: November 20, 1990
    Date of Patent: August 10, 1993
    Assignee: Enzon, Inc.
    Inventors: Kwang Nho, Shmuel Zalipsky, Frank Davis
  • Active carbonates of polyalkylene oxides for modification of polypeptides
    Patent number: 5122614
    Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: June 16, 1992
    Assignee: Enzon, Inc.
    Inventor: Shmuel Zalipsky