Patents by Inventor Chih-Chang Chu

Chih-Chang Chu 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: 20040063606
    Abstract: The present invention provides elastomeric copolyester amides, elastomeric copolyester urethanes, and methods for making the same. The polymers that are based on &agr;-amino acids and possess suitable physical, chemical and biodegradation properties. The polymers are useful as carriers of drugs or other bioactive substances. The polymers can be linked, intermixed, or a combination thereof, to one or more drugs.
    Type: Application
    Filed: October 14, 2003
    Publication date: April 1, 2004
    Inventors: Chih-Chang Chu, Ramaz Katsarava
  • Patent number: 6709668
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide (e.g., dextran) containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: March 23, 2004
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Patent number: 6592895
    Abstract: Precursor polyhydric alcohol esters where acyl moieties originate from aliphatic homopolymer or copolymer polyesters and contain free hydroxyl at their terminal ends, are reacted to provide 2-carboxy ethenyl groups. The resulting products can be used in formation of hydrogels for drug delivery or can be reacted to attach aminoxyl radical or drug molecule residue or other biologically active agent for delivery of these, for example, from vascular stents.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: July 15, 2003
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Meidong Lang, Chih-Chang Chu
  • Publication number: 20030125509
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide containing hydroxyl groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Preferably, the hydrophobic polymer is prepared by reacting the hydroxyls of a diol obtained by converting hydroxy of terminal carboxylic acid group of poly(lactic acid) to aminoethanol group, with an unsaturated group introducing compound which is acryloyl chloride or isocyanate having an unsaturated group at one end of the molecules.
    Type: Application
    Filed: February 21, 2003
    Publication date: July 3, 2003
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Patent number: 6583219
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide (e.g., dextran) containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: June 24, 2003
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Publication number: 20030109647
    Abstract: Precursor polyhydric alcohol esters where acyl moieties originate from aliphatic homopolymer or copolymer polyesters and contain free hydroxyl at their terminal ends, are reacted to provide 2-carboxy ethenyl groups. The resulting products can be used in formation of hydrogels for drug delivery or can be reacted to attach aminoxyl radical or drug molecule residue or other biologically active agent for delivery of these, for example, from vascular stents.
    Type: Application
    Filed: July 15, 2002
    Publication date: June 12, 2003
    Inventors: Meidong Lang, Chih-Chang Chu
  • Publication number: 20030027940
    Abstract: Biocompatible biodegradable polymer or copolymer is capped at one end and has free hydroxyl at the other end. The free hydroxyl can be reacted to link a plurality of functional groups some or each of which can be reacted to attach directly or via a spacer molecule a moiety containing an aminoxyl-containing radical or to a moiety comprising other drug molecule residue or a moiety comprising other biologically active agent residue.
    Type: Application
    Filed: March 20, 2002
    Publication date: February 6, 2003
    Inventors: Meidong Lang, Chih-Chang Chu
  • Publication number: 20030008971
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom In one embodiment, a vascular stent is coated with hydrogel with therapeutic agent entrapped therein.
    Type: Application
    Filed: May 13, 2002
    Publication date: January 9, 2003
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Patent number: 6503538
    Abstract: The present invention provides elastomeric copolyester amides, elastomeric copolyester urethanes, and methods for making the same. The polymers that are based on &agr;-amino acids and possess suitable physical, chemical and biodegradation properties. The polymers are useful as carriers of drugs or other bioactive substances.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: January 7, 2003
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Chih-Chang Chu, Ramaz Katsarava
  • Patent number: 6476204
    Abstract: Biodegradable hydrogels are formed by photocrosslinking dextran-maleic acid monoesters in which the average degree of substitution of each glucose unit of each &agr;-D-glucopyranosyl of dextran by maleic acid ranges from 0.60 to 1.6 and which have a weight average molecular weight ranging from 40,000 to 80,000 on a dextran basis. The hydrogels at pH 7 have maximum swelling ratios ranging from 500 to 1,500 percent. The hydrogels are characterized by increase in swelling ratio as average degree of substitution increases. The hydrogels are useful, for example, for drug delivery and solubility enhancers of drugs, as protective encapsulators of viruses used in gene therapy, and for conventional uses of hydrogels.
    Type: Grant
    Filed: January 19, 2001
    Date of Patent: November 5, 2002
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Sin-Hee Kim, Che-Youb Won, Chih-Chang Chu
  • Publication number: 20020161169
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide (e.g., dextran) containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom.
    Type: Application
    Filed: March 13, 2002
    Publication date: October 31, 2002
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Patent number: 6388047
    Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Preferably, the hydrophobic polymer is prepared by reacting the hydroxyls of a diol obtained by converting hydroxy of terminal carboxylic acid group of poly(lactic acid) to aminoethanol group, with an unsaturated group introducing compound which is acryloyl chloride or isocyanate having an unsaturated group at one end of the molecule.
    Type: Grant
    Filed: March 20, 2000
    Date of Patent: May 14, 2002
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Chee-Youb Won, Yeli Zhang, Chih-Chang Chu
  • Patent number: 6369037
    Abstract: A controlled release doxorubicin containing composition comprises doxorubicin physically entrapped in a dextran-methacrylate biodegradable hydrogel. The composition provides a rapid initial release of doxorubicin over a period of 5 to 7 hours followed by slow release. Increased degree of substitution in the dextran methacrylate decreases cumulative doxorubicin release. The composition provides higher cumulative release in acid pH (e.g., the stomach) than at physiological pH at lower degrees of substitution. The composition allows administration alternatives to the bolus intravenous and continuous intravenous methods of administration now used for doxorubicin. The composition can be prepared without the use of heat (which can result in heat destruction of doxorubicin) and is prepared without chemical cross-linker such as glutaraldehyde and the toxicity associated therewith.
    Type: Grant
    Filed: October 3, 2000
    Date of Patent: April 9, 2002
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Sin-Hee Kim, Chih-Chang Chu
  • Patent number: 5721131
    Abstract: A process for forming spatially oriented neo-vascular capillaries comprising: (a) providing a combination ultra-thin film (UTF) pattern of at least one cell adhesion promoter and at least one cell adhesion inhibitor wherein the cell adhesion promoters have a linewidth of between about 50-490 .mu.m; (b) seeding the combination UTF pattern with endothelial cells at an initial seeding cell density; (c) adding a first medium for incubating the seeded endothelial cells until the endothelial cells are grown to confluency; (d) replacing the first medium with a second medium at confluency; and (e) allowing the endothelial cells to differentiate into spatially oriented neo-vascular capillaries.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: February 24, 1998
    Assignee: United States of America as represented by the Secretary of the Navy
    Inventors: Alan S. Rudolph, Chih-Chang Chu, David A. Stenger, Barry J. Spargo, Jacque Georger
  • Patent number: 5610241
    Abstract: Graft polymers with reactive groups for linking to peptides for use in tissue engineering and to drugs to provide drug delivery systems and useful per se to release amino acids and useful, for example, for wound closure devices, pins, screws, anastomosis rings, and surgical implants, consist essentially of biodegradable homopolymer or copolymer backbone joined at carbon alpha to carbon of backbone carbonyl group, to side chain amino acid pendant group at a carbonyl moiety of said pendant group wherein said side chain contains reactive amino acid group. The graft polymers are prepared by reacting amino acid halide having other reactive groups protected, with biodegradable polymer containing carbanion on carbon alpha to carbon of carbonyl group, and then deprotecting the protected groups. Biodegradable polymer containing carbanion on carbon alpha to carbon of carbonyl group, for use in preparing the graft polymers herein or for otherwise reacting, e.g.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: March 11, 1997
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Keun H. Lee, Chee Y. Won, Chih-Chang Chu
  • Patent number: 5516881
    Abstract: Aminoxyl-containing radical is provided in polymers and copolymers by replacing a hydroxyl moiety in a carboxyl group at a chain end of a starting material biodegradable polymer or copolymer with imino or oxy linked to aminoxyl-containing radical to form an amide linkage or an oxycarbonyl linkage at the chain end of biocompatible polymers or copolymers to the aminoxyl-containing radical. Preferred starting material polymers and copolymers are prepared from the hydroxy alkyl carboxylic acid monomers glycolic acid and lactic acid. Preferred aminoxyl-containing radical is 2,2,6,6-tetramethylpiperidine-1-oxy. Product polymers are useful for aminoxyl-containing radical treatment of tumors, and to increase the efficiency of chemotherapy and ionizing radiation therapy of tumors and for the reconstruction of injured, diseased, or aged human blood vessels.
    Type: Grant
    Filed: August 10, 1994
    Date of Patent: May 14, 1996
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Keun-Ho Lee, Chih-Chang Chu, Jack H. Freed
  • Patent number: 5485496
    Abstract: Biomaterial medical devices or products, e.g., absorbable sutures or joint prostheses components, are gamma irradiation sterilized in the substantial absence of oxygen (e.g., vacuum treatment to 5.times.10.sup.-6 torr) while being maintained at a temperature about that of liquid nitrogen, with improved strength loss resistance compared to gamma irradiation sterilization under ambient conditions.
    Type: Grant
    Filed: September 22, 1994
    Date of Patent: January 16, 1996
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Keun-Ho Lee, Chih-Chang Chu