Patents by Inventor Xiangji Chen

Xiangji Chen 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: 10882945
    Abstract: A modified polyisobutylene-based polymer, method of making, and a medical device that includes such polymer, wherein the modified polyisobutylene-based polymer includes urethane, urea, or urethane-urea groups, hard segments, and soft segments, wherein the soft segments comprise phenoxy-containing polyisobutylene residues, and the hard segments include diisocyanate residues and optionally chain extender residues.
    Type: Grant
    Filed: March 20, 2019
    Date of Patent: January 5, 2021
    Assignee: Medtronic, Inc.
    Inventors: Kimberly A. Chaffin, Xiangji Chen, Matthew Jolly, SuPing Lyu, Peter L. Thor, Darrel F. Untereker, Zhaoxu Wang
  • Publication number: 20200354514
    Abstract: A method for preparing tyrosine derived polyarylates includes combining a desaminotyrosyl-tyrosine ethyl ester, a desaminotyrosyl-tyrosine benzylester, succinic acid and a catalyst in a flask to produce a first mixture. Methylene chloride is added to the first mixture to produce a first suspension. Diisopropylcarbodiimide (DIPC) is added to the first mixture to produce a first solution. The first solution is added to a non-solvent to produce a precipitate. The precipitate is dissolved in methylene chloride to form a polymer solution. The polymer solution is blended with a slurry to produce polymer shreds. The polymer shreds are blended with a second slurry to produce a tyrosine derived polyarylate.
    Type: Application
    Filed: July 23, 2020
    Publication date: November 12, 2020
    Applicant: MEDTRONIC, INC.
    Inventors: SATISH PULAPURA, FATIMA BUEVICH, XIANGJI CHEN, SUPING LYU
  • Publication number: 20200345901
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Application
    Filed: July 1, 2020
    Publication date: November 5, 2020
    Applicant: Medtronic, Inc.
    Inventors: Xiangji Chen, Satish Pulapura
  • Patent number: 10793670
    Abstract: A method for preparing tyrosine derived polyarylates includes combining a desaminotyrosyl-tyrosine ethyl ester, a desaminotyrosyl-tyrosine benzylester, succinic acid and a catalyst in a flask to produce a first mixture. Methylene chloride is added to the first mixture to produce a first suspension. Diisopropylcarbodiimide (DIPC) is added to the first mixture to produce a first solution. The first solution is added to a non-solvent to produce a precipitate. The precipitate is dissolved in methylene chloride to form a polymer solution. The polymer solution is blended with a slurry to produce polymer shreds. The polymer shreds are blended with a second slurry to produce a tyrosine derived polyarylate.
    Type: Grant
    Filed: May 7, 2018
    Date of Patent: October 6, 2020
    Assignee: MEDTRONIC, INC.
    Inventors: Satish Pulapura, Fatima Buevich, Xiangji Chen, Suping Lyu
  • Patent number: 10767006
    Abstract: A method for hydrogenating tyrosine derived polyarylates includes dissolving a second polyarylate with DMF in a flask to produce a first solution. A catalyst is added to the first solution to produce a polymer solution. The polymer solution is filtered through a Celite bed to produce a filtrate. The filtrate is added to water and stirred to precipitate the polyarylate.
    Type: Grant
    Filed: May 7, 2018
    Date of Patent: September 8, 2020
    Assignee: MEDTRONIC, INC.
    Inventors: Satish Pulapura, Dan Thanh Le, Xiangji Chen, Suping Lyu, Fatima Buevich
  • Patent number: 10736998
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Grant
    Filed: May 9, 2019
    Date of Patent: August 11, 2020
    Assignee: Medtronic, Inc.
    Inventors: Xiangji Chen, Satish Pulapura
  • Patent number: 10632206
    Abstract: The invention generally relates to zwitterionic polymers (including zwitterionic copolymers), such as polymethacrylic structures, with pendent functional moieties, such as therapeutic or biologic moieties. More particularly, the invention relates to phosphorylcholine-substituted methacrylic polymers prepared by free radical polymerization and click chemistry, for example, and compositions and products comprising same, as well as related methods and uses of the compositions, for example, as biological or therapeutic agents and in drug delivery thereof.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: April 28, 2020
    Assignee: UNIVERSITY OF MASSACHUSETTS
    Inventors: Todd Emrick, Xiangji Chen, Samantha Page
  • Patent number: 10472493
    Abstract: A composition, article, and method for increasing the hydrolytic stability of a polymer; wherein a composition includes: a polymer comprising functional groups having hydrolyzable bonds; a carbodiimide compound; and a weak base (or hindered amine); wherein the carbodiimide compound and weak base (or hindered amine) are used in amounts effective to decrease the rate and/or extent of hydrolytic degradation of the polymer relative to either used alone in the same amount with the polymer.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: November 12, 2019
    Assignee: Medtronic, Inc.
    Inventors: Patricia E. Dunn, Ronald A. Drake, Xiangji Chen, Samuel E. Owings
  • Patent number: 10442757
    Abstract: A method for preparing diphenol compounds includes adding a hydroxyphenyl carboxylic acid, a tyrosine ethyl ester, hydroxybenzotriazole hydrate and a solvent and stirring to produce a first solution. EDCI HCl is added to the first solution to produce a first mixture. Ethyl acetate is added to the first mixture to produce a second mixture. The second mixture is added to sodium chloride to produce a third mixture having layer separation. An aqueous layer is removed from the third mixture. The third mixture is extracted with reagents after the aqueous layer has been removed from the third mixture to produce a fourth mixture. Magnesium sulfate is added to the fourth mixture to produce a fifth mixture. The fifth mixture is filtered to produce filtrate. The filtrate is concentrated. Crystallization of the concentrated filtrate is induced. Methylene chloride is added to the crystallized filtrate to produce a solid product.
    Type: Grant
    Filed: May 7, 2018
    Date of Patent: October 15, 2019
    Assignee: Medtronic, Inc.
    Inventors: Satish Pulapura, Fatima Buevich, Xiangji Chen, Suping Lyu
  • Publication number: 20190292327
    Abstract: A poly(ether-carbonate)-based polymer and a medical device that includes such polymer, wherein the poly(ether-carbonate)-based polymer includes urethane, urea, or urethane-urea groups, hard segments, and soft segments, wherein the soft segments include poly(ether-carbonate) residues and at least one of polyisobutylene (PIB) residues and hydrogenated polybutadiene residues, and the hard segments include diisocyanate residues and optionally chain extender residues.
    Type: Application
    Filed: March 20, 2019
    Publication date: September 26, 2019
    Inventors: Kimberly A. CHAFFIN, Xiangji CHEN, Matthew JOLLY, SuPing LYU, Peter L. THOR, Darrel F. UNTEREKER, Zhaoxu WANG
  • Publication number: 20190292302
    Abstract: A modified polyisobutylene-based polymer, method of making, and a medical device that includes such polymer, wherein the modified polyisobutylene-based polymer includes urethane, urea, or urethane-urea groups, hard segments, and soft segments, wherein the soft segments comprise phenoxy-containing polyisobutylene residues, and the hard segments include diisocyanate residues and optionally chain extender residues.
    Type: Application
    Filed: March 20, 2019
    Publication date: September 26, 2019
    Inventors: Kimberly A. CHAFFIN, Xiangji CHEN, Matthew JOLLY, SuPing LYU, Peter L. THOR, Darrel F. UNTEREKER, Zhaoxu WANG
  • Publication number: 20190262510
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Application
    Filed: May 9, 2019
    Publication date: August 29, 2019
    Applicant: Medtronic, Inc.
    Inventors: Xiangji Chen, Satish Pulapura
  • Patent number: 10314951
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Grant
    Filed: April 26, 2018
    Date of Patent: June 11, 2019
    Assignee: Medtronic, Inc.
    Inventors: Xiangji Chen, Satish Pulapura, Fatima Buevich
  • Publication number: 20190125938
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Application
    Filed: April 26, 2018
    Publication date: May 2, 2019
    Applicant: TYRX, Inc.
    Inventors: Xiangji Chen, Satish Pulapura, Fatima Buevich
  • Publication number: 20190111186
    Abstract: A medical device, a method for preparation thereof, and use thereof are provided. The medical device comprises a thermoplastic elastomer that is composed of soft segments and hard segments. The method for preparing a medical device comprising a thermoplastic elastomer, comprises forming the thermoplastic elastomer into tubing or other shapes via extrusion, molding, or coating, assembling the tubing or other shapes with other parts including: cables, coils, coated cables, or coated coils, and bonding the tubing, cables, or coils with other components including: other tubing components, cables, coils, sleeves, electrical pulse generator, defibrillation shock generator, electrodes, sensors, or drug release components. The medical device is used for correcting cardiac rhythm, defibrillating, assisting hearts, sensing, stimulating neurological systems, gastrointestinal system, or skeletomuscular tissues or organs.
    Type: Application
    Filed: March 2, 2017
    Publication date: April 18, 2019
    Inventors: Suping LYU, XiangJi CHEN, Jing CHEN, Haining NA, Jin ZHU
  • Publication number: 20190112411
    Abstract: Disclosed is a segmented thermoplastic elastomer that can be a polyurethane, polyurea, or polyurethane-urea comprising soft segments and hard segments, wherein the soft segments are made of polyolefin diols or polyolefin diamine that may have 0 to 1000 carbon atoms in the main chain, wherein each carbon atom in the main chain may have 0 to 2 side chains and each side chain may have 0 to 30 carbon atoms, the hard segment is made of a diisocyante and a chain extender, the hard segments make up 10-60% of the elastomer and the soft segments make up the rest, the number-average molecular weight of the elastomer is 5×103-1000×103 g/mol, the ultimate elongation of the elastomer is 100-1000%, the Young's modulus is 1 to 3,000 MPa, and the ultimate tensile strength is 10-100 MPa. Also disclosed are a method for preparing the segmented thermoplastic elastomer and use of segmented thermoplastic elastomer.
    Type: Application
    Filed: March 2, 2017
    Publication date: April 18, 2019
    Inventors: Jing CHEN, Haining NA, Jin ZHU, Suping LYU, XiangJi CHEN
  • Publication number: 20180355104
    Abstract: A method for hydrogenating tyrosine derived polyarylates includes dissolving a second polyarylate with DMF in a flask to produce a first solution. A catalyst is added to the first solution to produce a polymer solution. The polymer solution is filtered through a Celite bed to produce a filtrate. The filtrate is added to water and stirred to precipitate the polyarylate.
    Type: Application
    Filed: May 7, 2018
    Publication date: December 13, 2018
    Applicant: Tyrx, Inc.
    Inventors: SATISH PULAPURA, DAN THANH LE, XIANGJI CHEN, SUPING LYU, FATIMA BUEVICH
  • Publication number: 20180355103
    Abstract: A method for preparing tyrosine derived polyarylates includes combining a desaminotyrosyl-tyrosine ethyl ester, a desaminotyrosyl-tyrosine benzylester, succinic acid and a catalyst in a flask to produce a first mixture. Methylene chloride is added to the first mixture to produce a first suspension. Diisopropylcarbodiimide (DIPC) is added to the first mixture to produce a first solution. The first solution is added to a non-solvent to produce a precipitate. The precipitate is dissolved in methylene chloride to form a polymer solution. The polymer solution is blended with a slurry to produce polymer shreds. The polymer shreds are blended with a second slurry to produce a tyrosine derived polyarylate.
    Type: Application
    Filed: May 7, 2018
    Publication date: December 13, 2018
    Applicant: TYRX, Inc.
    Inventors: SATISH PULAPURA, FATIMA BUEVICH, XIANGJI CHEN, SUPING LYU
  • Publication number: 20180354892
    Abstract: A method for preparing diphenol compounds includes adding a hydroxyphenyl carboxylic acid, a tyrosine ethyl ester, hydroxybenzotriazole hydrate and a solvent and stirring to produce a first solution. EDCl HCl is added to the first solution to produce a first mixture. Ethyl acetate is added to the first mixture to produce a second mixture. The second mixture is added to sodium chloride to produce a third mixture having layer separation. An aqueous layer is removed from the third mixture. The third mixture is extracted with reagents after the aqueous layer has been removed from the third mixture to produce a fourth mixture. Magnesium sulfate is added to the fourth mixture to produce a fifth mixture. The fifth mixture is filtered to produce filtrate. The filtrate is concentrated. Crystallization of the concentrated filtrate is induced. Methylene chloride is added to the crystallized filtrate to produce a solid product.
    Type: Application
    Filed: May 7, 2018
    Publication date: December 13, 2018
    Applicant: TYRX, Inc.
    Inventors: Satish Pulapura, Fatima Buevich, Xiangji Chen, Suping Lyu
  • Patent number: 10034969
    Abstract: A kit includes a mesh substrate and a polymer that is fixed to the mesh substrate. The polymer includes an active agent that is configured to elute over time. The kit further includes a hemostatic agent. The hemostatic agent is separate from the mesh substrate and the polymer. Systems and methods are disclosed.
    Type: Grant
    Filed: March 6, 2018
    Date of Patent: July 31, 2018
    Assignee: TYRX, Inc.
    Inventors: Xiangji Chen, Satish Pulapura, Fatima Buevich