Patents by Inventor Kam W. Leong

Kam W. Leong 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: 6475995
    Abstract: Nanoparticle coacervates of nucleic acids and polycations serve as effective vaccines when administered orally. They can induce immunity to a variety of disease causing agents and raise a protective response to allergens.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: November 5, 2002
    Assignee: The Johns Hopkins University
    Inventors: Krishnendu Roy, Shau-Ku Huang, Hugh Sampson, Kam W. Leong
  • Publication number: 20020151617
    Abstract: Biodegradable polymers are described comprising the recurring monomeric units shown in formula I or II: 1
    Type: Application
    Filed: January 15, 2002
    Publication date: October 17, 2002
    Inventors: Hai-Quan Mao, Kam W. Leong, Zhong Zhao, James P. English
  • Publication number: 20020137814
    Abstract: Biodegradable, flowable or flexible polymer compositions are described comprising a polymer having the recurring monomeric units shown in formula I: 1
    Type: Application
    Filed: December 4, 2001
    Publication date: September 26, 2002
    Inventors: Wenbin Dang, Irina Kadiyala, Zhong Zhao, James P. English, Hai-Quan Mao, Kam W. Leong
  • Publication number: 20020094569
    Abstract: A multi-layered microcapsule has an inner extracellular matrix and an outer shell. The inner extracellular matrix includes a first inner layer of biopolymer and a second intermediate layer of polymer that provides partial immune-protection and holds the first layer in place. The outer shell can form an exoskeleton to provide mechanical stability. Each of the individual layers can be varied to optimize mechanical stability, cell function, and immuno-protection.
    Type: Application
    Filed: October 12, 2001
    Publication date: July 18, 2002
    Inventors: Hanry Yu, Kam W. Leong, Ser-Mien Chia, Andrew C.A. Wan
  • Patent number: 6419709
    Abstract: An essentially non-osteoconductive medical device is described comprising a biodegradable terephthalate copolymer comprising the recurring monomeric units shown in formula I: wherein R is a divalent organic moiety; x is ≧1; and n is 3-7,500, where the biodegradable polymer is sufficiently pure to be biocompatible and is capable of forming biocompatible residues upon biodegradation. Compositions containing the copolymers and biologically active substances, articles useful for implantation or injection into the body fabricated from the compositions, and methods for controllably releasing biologically active substances using the copolymers, are also described.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: July 16, 2002
    Assignees: Guilford Pharmaceuticals, Inc., John Hopkins University School of Medicine
    Inventors: Hai-quan Mao, Kam W. Leong, Zhong Zhao, Wensin Dang, James P. English, David P. Nowotnik
  • Publication number: 20020091230
    Abstract: Biodegradable terephthalate polymers are described comprising the recurring monomeric units shown in formula I: 1
    Type: Application
    Filed: August 2, 2001
    Publication date: July 11, 2002
    Inventors: Hai-Quan Mao, Kam W. Leong, Wenbin Dang, Hungnan Lo, Zhong Zhao, David P. Nowotnik, James P. English
  • Patent number: 6410517
    Abstract: A target-specific gene delivery system is made of enzymatically degradable gelatin and nucleic acids (DNA or RNA) microparticles with a linking moiety or a targeting ligand attached to the surface. The delivery system can be made by a simple method. Targeting ligands can be attached to the microparticle directly or via a linking moiety. The linkage design allows the attachment of any molecule onto the microparticle surface including antibodies, cell adhesion molecules, hormones and other cell-specific ligands.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: June 25, 2002
    Assignee: Johns Hopkins University
    Inventors: Vu L. Truong, Thomas August, Kam W. Leong
  • Patent number: 6403675
    Abstract: Biodegradable, flowable or flexible polymer compositions are described comprising a polymer having the recurring monomeric units shown in formula I: wherein: each of R and R′ is independently straight or branched alkylene, either unsubstituted or substituted with one or more non-interfering substituents; L is a divalent cycloaliphatic group; R″ is selected from the group consisting of H, alkyl, alkoxy, aryl, aryloxy, heterocyclic or heterocycloxy; and n is 5 to 1,000, wherein said biodegradable polymer is biocompatible before and upon biodegradation. In one embodiment, one or more of R, R′ or R″ is a biologically active substance. Amorphous compositions containing a biologically active substance, in addition to the polymer, and methods for controllably releasing biologically active substances using the compositions, are also described.
    Type: Grant
    Filed: April 30, 1998
    Date of Patent: June 11, 2002
    Assignees: Guilford Pharmaceuticals, Inc., Johns Hopkins University
    Inventors: Wenbin Dang, Hai-quan Mao, Irina Kadiyala, Kam W. Leong, Zhong Zhao, James P. English
  • Publication number: 20020061326
    Abstract: A medical device and method for transportation and release of a therapeutic agent into a mammalian body are disclosed. The medical device is coated with alternating layers of a negatively charged therapeutic agent and a cationic polyelectrolyte, following a controlled adsorption technique. The method is simple,' with minimal perturbation to the therapeutic agent and uses clinically acceptable biopolymers such as human serum albumin. The amount of the therapeutic agent that can be delivered by this technique is optimized by the number of the layers of the therapeutic agent adsorbed on the surface of medical device. There is a washing step between alternate layers of the therapeutic agent and cationic polyelectrolyte carrier, so that the amount of the therapeutic agent on the insertable medical device represents the portion that is stably entrapped and adsorbed on to the medical device.
    Type: Application
    Filed: January 2, 2001
    Publication date: May 23, 2002
    Inventors: Wei-ping Li, Hai-Quan Mao, Kam W. Leong
  • Patent number: 6376644
    Abstract: Biodegradable polymers are described comprising the recurring monomeric units shown in formula I or II: wherein X is —O— or —NR′—, where R′ is H or alkyl; L is a branched or straight chain aliphatic group having from 1-20 carbon atoms; M1 and M2 are each independently (1) a branched or straight chain aliphatic group having from 1-20 carbon atoms; or (2) a branched or straight chain, oxy-, carboxy- or amino-aliphatic group having from 1-20 carbon atoms; Y is —O—, —S— or —NR′—, where R′ is H or alkyl; R is H, alkyl, alkoxy, aryl, aryloxy, heterocyclic or heterocycloxy; the molar ratio of x:y is about 1; the molar ratio n:(x or y) is between about 200:1 and 1:200; and the molar ratio q:r is between about 1:99 and 99:1; wherein said biodegradable polymer is biocompatible before and upon biodegradat.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: April 23, 2002
    Assignees: Guilford Pharmaceuticals, Inc., Johns Hopkins University School of Medicine
    Inventors: Hai-Quan Mao, Kam W. Leong, Zhong Zhao, James P. English
  • Patent number: 6322797
    Abstract: Biodegradable terephthalate polymers are described comprising the recurring monomeric units shown in formula I: wherein R is a divalent organic moiety; R′ is an aliphatic, aromatic or heterocyclic residue; x is ≧1; and n is 0-5,000, wherein the biodegradable polymer is biocompatible before and upon biodegradation. Processes for preparing the polymers, compositions containing the polymers and biologically active substances, articles useful for implantation or injection into the body fabricated from the compositions, and methods for controllably releasing biologically active substances using the polymers, are also described.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: November 27, 2001
    Assignees: Guilford Pharmaceuticals, Inc., Johns Hopkins University
    Inventors: Hai-Quan Mao, Kam W. Leong, Wenbin Dang, Hungnan Lo, Zhong Zhao, David P. Nowotnik, James P. English
  • Patent number: 6238687
    Abstract: Biodegradable polymer compositions that degrade in vivo into non-toxic residues are described. In part, the present invention is directed to such polymers containing phosphorus and desaminotyrosyl L-tyrosine linkages in the polymer backbone. Processes for preparing such polymers, compositions containing such polymers and biologically active substances, articles useful for implantation or injection into the body fabricated from the compositions, and methods for controllably releasing biologically active substances using the polymers, are also described.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: May 29, 2001
    Assignee: Johns Hopkins University School of Medicine
    Inventors: Hai-Quan Mao, Kam W. Leong
  • Patent number: 6207195
    Abstract: 4-Phenylbutyrate exerts many beneficial biological effects. It appears to induce the transcription of certain promoters, as well as having a remedial effect on proteins which are aberrantly localized within the cell. In addition, it appears to cause cells to developmentally differentiate. The present invention provides nanosphere formulations of 4-phenylbutyrate and other drugs which remediate defective protein localization intracellularly. These formulations permit lower concentrations of drugs to be administered, providing both cost and safety benefits.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: March 27, 2001
    Assignee: The Johns Hopkins University
    Inventors: Scott Walsh, Ronald Rubenstein, Pam Zeitlin, Kam W. Leong
  • Patent number: 6193970
    Abstract: A method of stimulating a systemic immune response to a tumor cell or antigen associated with a pathogen by administering a mixture of a controlled release vehicle containing an immunopotentiating agent and antigen is described.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: February 27, 2001
    Assignee: The Johns Hopkins University School of Medicine
    Inventors: Drew Pardoll, Rosa Azhari, Kam W. Leong, Paul K Golumbe, Elizabeth Jaffee, Hyam Levitsky, Audrey Lazenby
  • Patent number: 6166173
    Abstract: Biodegradable polymers are described comprising the recurring monomeric units shown in formula I or II: wherein X is --O-- or --NR'--, where R' is H or alkyl; L is a branched or straight chain aliphatic group having from 1-20 carbon atoms; M.sub.1 and M.sub.2 are each independently (1) a branched or straight chain aliphatic group having from 1-20 carbon atoms; or (2) a branched or straight chain, oxy-, carboxy- or amino-aliphatic group having from 1-20 carbon atoms; Y is --O--, --S-- or --NR'--, where R' is H or alkyl; R is H, alkyl, alkoxy, aryl, aryloxy, heterocyclic or heterocycloxy; the molar ratio of x:y is about 1; the molar ratio n:(x or y) is between about 200:1 and 1:200; and the molar ratio q:r is between about 1:99 and 99:1; wherein said biodegradable polymer is biocompatible before and upon biodegradat.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: December 26, 2000
    Assignees: Guilford Pharmaceuticals Inc., Johns Hopkins University
    Inventors: Hai-Quan Mao, Kam W. Leong, Zhong Zhao, James P. English
  • Patent number: 6156346
    Abstract: A delivery system that releases a diagnostic marker or therapeutic agent in a manner sensitive to the concentration of urease in a physiological compartment, particularly the gastrointestinal tract, and methods of use.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: December 5, 2000
    Assignee: Johns Hopkins University
    Inventors: Xiaoru Chen, P. Jay Pasricha, Kam W. Leong
  • Patent number: 6153212
    Abstract: A medical device is described comprising a biodegradable terephthalate copolymer comprising the recurring monomeric units shown in formula I below: ##STR1## wherein R is a divalent organic moiety; R' is an aliphatic, aromatic, or heterocyclic residue; x is .gtoreq.1; and n is 3-7,500, and where the biodegradable terephthalate copolymer is sufficiently pure to be biocompatible and is capable of forming biocompatible residues upon biodegradation. In addition, compositions containing the copolymers and biologically active substances, articles useful for implantation or injection into the body fabricated from the compositions, and methods for controllably releasing biologically active substances using the copolymers, are also described.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: November 28, 2000
    Assignees: Guilford Pharmaceuticals Inc., Johns Hopkins University School of Medicine
    Inventors: Hai-quan Mao, Kam W. Leong, Zhong Zhao, Wenbin Dang, James P. English, David P. Nowotnik
  • Patent number: 6126956
    Abstract: A non-abusable, non-inflammatory, biocompatible, non-biodegradable, subcutaneous, polymeric implant for the prolonged, controlled release of hydromorphone with near zero-order kinetics is described. Methods of alleviating cancer pain and treating opioid drug addiction with the implant are also described.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: October 3, 2000
    Assignee: Axxia Technologies
    Inventors: Stuart A. Grossman, Kam W. Leong, Glenn J. Lesser, Hungnan Lo
  • Patent number: 6025337
    Abstract: A target-specific gene delivery system is made of enzymatically degradable gelatin and nucleic acids (DNA or RNA) microparticles with a linking moiety or a targeting ligand attached to the surface. The delivery system can be made by a simple method. Targeting ligands can be attached to the microparticle directly or via a linking moiety. The linkage design allows the attachment of any molecule onto the microparticle surface including antibodies, cell adhesion molecules, hormones and other cell-specific ligands.
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: February 15, 2000
    Assignee: Johns Hopkins University
    Inventors: Vu L. Truong, Thomas August, Kam W. Leong
  • Patent number: 6008318
    Abstract: A process for making a phosphoester polymer comprising the recurring monomeric units of formula I: ##STR1## wherein: X is --O-- or --NR"--, where R" is H or alkyl;L is a divalent organic moiety;R' is H, alkyl, alkoxy, aryl, aryloxy, heterocyclic, or heterocycloxy; andn is between about 25 to 2,000,is described. The process comprises the steps of:(a) polymerizing in the presence of a solvent p moles of a di-XH compound having formula II:H--X--L--X--H IIwherein X and L are as defined above, with q moles, where p.apprxeq.q, of a phosphorodihalo compound to form a polymer of formula I, wherein n is about 12 to 1000, having a first molecular weight Mw.sub.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: December 28, 1999
    Assignees: Guilford Pharmaceuticals Inc., Johns Hopkins University
    Inventors: Zhong Zhao, Hai-quan Mao, Kam W. Leong