Patents by Inventor Christopher N. Ta

Christopher N. Ta 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: 20140357559
    Abstract: A strain-hardened interpenetrating polymer network (IPN) hydrogel is provided. The interpenetrating polymer network hydrogel is based on two different networks. The first network is a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups. The second network is a non-silicone network of ionizable monomers. The second network has been polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. An aqueous salt solution having a neutral pH is used to ionize and swell the second network in the interpenetrating polymer network. The swelling of the second network is constrained by the first network, and this constraining effect results in an increase in effective physical cross-links within the interpenetrating polymer network, and, in turn, an increase its elastic modulus.
    Type: Application
    Filed: August 19, 2014
    Publication date: December 4, 2014
    Inventors: David Myung, Laura Hartmann, Jaan Noolandi, Christopher N. Ta, Curtis W. Frank
  • Patent number: 8821583
    Abstract: A strain-hardened interpenetrating polymer network (IPN) hydrogel is provided. The interpenetrating polymer network hydrogel is based on two different networks. The first network is a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups. The second network is a non-silicone network of ionizable monomers. The second network has been polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. An aqueous salt solution having a neutral pH is used to ionize and swell the second network in the interpenetrating polymer network. The swelling of the second network is constrained by the first network, and this constraining effect results in an increase in effective physical cross-links within the interpenetrating polymer network, and, in turn, an increase its elastic modulus.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: September 2, 2014
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David Myung, Laura Hartmann, Jean Noolandi, Christopher N. Ta, Curtis W. Frank
  • Publication number: 20110184513
    Abstract: A material that can be applied as implants designed to artificially replace or augment the cornea, such as an artificial cornea, corneal onlay, or corneal inlay (intrastromal lens) is provided. The artificial corneal implant has a double network hydrogel with a first network interpenetrated with a second network. The first network and the second network are based on biocompatible polymers. At least one of the network polymers is based on a hydrophilic polymer. The artificial cornea or implant has epithelialization promoting biomolecules that are covalently linked to the surface of the double network hydrogel using an azide-active-ester chemical linker. Corneal epithelial cells or cornea-derived cells are adhered to the biomolecules. The double network has a physiologic diffusion coefficient to allow passage of nutrients to the adhered cells.
    Type: Application
    Filed: December 20, 2010
    Publication date: July 28, 2011
    Inventors: David Myung, Jaan Noolandi, Alan J. Smith, Curtis W. Frank, Christopher N. Ta, Yin Hu, Won-Gun Koh, Michael R. Carrasco, Laura Hartmann
  • Publication number: 20110182968
    Abstract: The present invention provides materials that have high glucose and oxygen permeability, strength, water content, and resistance to protein adsorption. The materials include an interpenetrating polymer network (IPN) hydrogel that is coated with biomolecules. The IPN hydrogels include two interpenetrating polymer networks. The first polymer network is based on a hydrophilic telechelic macromonomer. The second polymer network is based on a hydrophilic monomer. The hydrophilic monomer is polymerized and cross-linked to form the second polymer network in the presence of the first polymer network. In a preferred embodiment, the hydrophilic telechelic macromonomer is PEG-diacrylamide, PEG-diacrylate or PEG-dimethacrylate and the hydrophilic monomer is an acrylic-based monomer. Any biomolecules may be linked to the IPN hydrogels, but are preferably biomolecules that support the growth of cornea-derived cells. The material is designed to serve as a corneal prosthesis.
    Type: Application
    Filed: December 20, 2010
    Publication date: July 28, 2011
    Inventors: David Myung, Christopher N. Ta, Curtis W. Frank, Won-Gun Koh, Jaan Noolandi, Laura Hartmann
  • Publication number: 20110166247
    Abstract: The present invention provides interpenetrating polymer network hydrogels that have high oxygen permeability, strength, water content, and resistance to protein adsorption. The hydrogels include two interpenetrating polymer networks. The first polymer network is based on a hydrophilic telechelic macromonomer. The second polymer network is based on a hydrophilic monomer. The hydrophilic monomer is polymerized and cross-linked to form the second polymer network in the presence of the first polymer network. The telechelic macromonomer preferably has a molecular weight of between about 575 Da and about 20,000 Da. Mixtures of molecular weights may also be used. In a preferred embodiment, the hydrophilic telechelic macromonomer is PEG-diacrylamide and the hydrophilic monomer is an acrylic-based monomer. The material is designed to serve as a contact lens.
    Type: Application
    Filed: December 20, 2010
    Publication date: July 7, 2011
    Inventors: David Myung, Jaan Noolandi, Christopher N. Ta, Curtis W. Frank, Laura Hartmann
  • Publication number: 20100174021
    Abstract: Three-dimensionally (3-D) shaped interpenetrating double network (IPN) hydrogel based on a first network and a second network are provided. The 3-D shape is characterized by a non-uniform distribution of the second network (e.g. carboxylic acid groups) when in hydrated state. The 3-D shape can further be characterized by changes in the radius of curvature of the shape. The 3-D IPN hydrogel is created by applying a non-uniform illumination pattern to polymerize the second network of monomers within a layer of a first network. In hydrated state, the second network causes a swelling force that is resisted by the first network. The non-uniformal distribution of the second network with the first network is responsible for the 3-D of the resulting IPN. The invention can find use in ophthalmic applications as well as non-ophthalmic applications.
    Type: Application
    Filed: December 11, 2009
    Publication date: July 8, 2010
    Inventors: Philip Huie, JR., Dale Jon Waters, Curtis W. Frank, Christopher N. Ta, Ariane C. Tom
  • Publication number: 20090117166
    Abstract: A bio-mimetic or bio-implantable material based on a sequential process of coupling biomolecule layers to a polymer layer is provided. In general, the material could be based on two or more biomolecule layers starting with one of the layers covalently linked to the polymer layer via cross-linkers and the other layers sequentially and covalently linked using cross-linkers to the previously added layer. The polymer layer could be a hydrogel or an interpenetrating polymer network hydrogel. The first layer of biomolecules could be a collagen type, fibronectin, laminin, extracellular matrix protein, or any combinations thereof. The second layer of biomolecules typically is a growth factor, protein or stimulant. The cross-linkers are either water soluble or insoluble bifunctional cross-linkers or azide-active-ester crosslinkers. The material and process as taught in this invention are useful in the field of tissue engineering and wound healing.
    Type: Application
    Filed: August 15, 2008
    Publication date: May 7, 2009
    Inventors: David Myung, Stayce Beck, Jaan Noolandi, Christopher N. Ta, Jennifer R. Cochran, Curtis W. Frank
  • Publication number: 20080269370
    Abstract: A strain-hardened interpenetrating polymer network (IPN) hydrogel is provided. The interpenetrating polymer network hydrogel is based on two different networks. The first network is a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups. The second network is a non-silicone network of ionizable monomers. The second network has been polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. An aqueous salt solution having a neutral pH is used to ionize and swell the second network in the interpenetrating polymer network. The swelling of the second network is constrained by the first network, and this constraining effect results in an increase in effective physical cross-links within the interpenetrating polymer network, and, in turn, an increase its elastic modulus.
    Type: Application
    Filed: February 15, 2008
    Publication date: October 30, 2008
    Inventors: David Myung, Laura Hartman, Jean Noolandi, Christopher N. Ta, Curtis W. Frank