Patents by Inventor Srinivasa R. Raghavan

Srinivasa R. Raghavan 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: 11964250
    Abstract: Methods and systems for synthesizing multicompartment capsules are disclosed, as well as multicompartment polymer capsules formed in accordance with disclosed techniques. At least one plurality of polymer capsules are formed via a capsule-forming process. A feed solution and a reservoir solution are provided, each comprising a biopolymer. The feed solution biopolymer and the reservoir solution biopolymer have opposite charges. Droplets of the feed solution are introduced into the reservoir solution, thereby forming via electrostatic complexation a plurality of polymer capsules. At least a portion of the resulting polymer capsules are then encapsulated in a larger polymer capsule via a similar process, wherein the feed solution utilized for the encapsulation process also comprises the formed smaller capsules.
    Type: Grant
    Filed: August 14, 2018
    Date of Patent: April 23, 2024
    Inventors: Hyuntaek Oh, Srinivasa R. Raghavan, William E. Bentley, Xi Lu, Jessica Lynn Terrell, So Hyun Ahn
  • Publication number: 20240122861
    Abstract: Surprisingly, electric fields can induce a dramatic response in soft materials made from nonconducting biopolymers. Capsules made from Alginate, Chitosan, and Gellan gum, all of which are charged polysaccharides and are biocompatible and biodegradable. Each capsule is formed by crosslinking biopolymer chains via physical (ionic/electrostatic) interactions. Under a DC electric field, the capsules rupture and disintegrate in a span of less than five minutes. The mechanism for the electroresponse is attributed to electrophoretic rearrangement of ions and/or polyelectrolyte chains in the capsule. Alginate capsules first swell anisotropically on their side closer to the anode (+ electrode). Cations migrate away from the anode, thereby lowering the crosslink density on that side. As further crosslinks are lost from the anode side, the capsule eventually breaks. A valve design utilizes an orifice that is blocked by a capsule and the valve is opened when the capsule is dislodged by the field.
    Type: Application
    Filed: October 18, 2023
    Publication date: April 18, 2024
    Inventors: Srinivasa R. Raghavan, Ankit Gargava, Wenhao Xu
  • Publication number: 20230279282
    Abstract: The problem of lost circulation is pertinent to the oil industry. To prevent fluid loss, a lost circulation material (LCM), or more generally, a plugging material, can be used to effectively plug the fractures in the rock formation. If the fractures are in the production zone, it is also ideal to unplug them when the drilling operation is complete. Therefore, a material engineered to degrade after a desired period would be useful. In examples, a plugging material has been developed by gelling an oil-based fluid using a low molecular weight gelator, dibenzylidene sorbitol (DBS). DBS gels are robust and show plugging behavior. DBS is shown to chemically degrade in presence of an acid. Hence, a self-degrading gel can be synthesized by incorporating an acid into the system. Further, by varying the type and concentration of the acid, the degradation time of the gel can be controlled.
    Type: Application
    Filed: February 23, 2023
    Publication date: September 7, 2023
    Inventors: Faraz A. BURNI, Srinivasa R. RAGHAVAN, Joseph WEE, David CHAPPELL, Shanshan HUANG
  • Publication number: 20220347341
    Abstract: In various aspects and embodiments, the present invention provides hemostatic products and methods for treating wounds, including cavity wounds and non-compressible hemorrhage. In various embodiments, the invention employs hydrophobically-modified polymer foams, gels, or pastes.
    Type: Application
    Filed: October 5, 2020
    Publication date: November 3, 2022
    Inventors: Matthew DOWLING, Srinivasa R. RAGHAVAN, Hema CHOUDHARY
  • Publication number: 20220226625
    Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.
    Type: Application
    Filed: April 7, 2022
    Publication date: July 21, 2022
    Inventors: Matthew Dowling, Srinivasa R. Raghavan
  • Patent number: 11298517
    Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.
    Type: Grant
    Filed: January 18, 2019
    Date of Patent: April 12, 2022
    Assignee: University of Maryland, College Park
    Inventors: Matthew Dowling, Srinivasa R. Raghavan
  • Publication number: 20210324365
    Abstract: A method of system of forming a biopolymer hydrogel structure includes a mold loaded with a cation. At least a portion of the surface of the mold is exposed to a solution comprising a gellable polymer such as alginate. An electric potential is applied to the mold so that the cation therein and the gellable polymer migrate via electrophoresis toward the surface portion, thereby interacting and forming a hydrogel structure adjacent to the surface portion.
    Type: Application
    Filed: April 20, 2021
    Publication date: October 21, 2021
    Applicant: University of Maryland, College Park
    Inventors: Srinivasa R. Raghavan, So Hyun Ahn, Ankit Gargava
  • Publication number: 20200179895
    Abstract: Methods of synthesizing multilayer structures, including multilayer capsules, tubes and hair-covered substrates, are provided. A substrate is provided comprising a polymerization initiator. The initiator-loaded substrate is exposed to a solution comprising a monomer and crosslinker. The initiator diffuses outwardly from the substrate, thereby initiating polymerization of the monomer and forming a layered structure comprising a polymer portion disposed on an exterior surface of the substrate. The process may be repeated for a selected number of cycles, thereby forming a multilayer structure having a selected number of layers. The composition, thickness and properties of each layer are selectively controlled. Multilayer structures formed in accordance with the methodologies are also provided.
    Type: Application
    Filed: July 17, 2018
    Publication date: June 11, 2020
    Applicant: University of Maryland, College Park
    Inventors: Brady C. Zarket, Srinivasa R. Raghavan, Hanchu Wang
  • Publication number: 20200171456
    Abstract: Methods and systems for synthesizing multicompartment capsules are disclosed, as well as multicompartment polymer capsules formed in accordance with disclosed techniques. At least one plurality of polymer capsules are formed via a capsule-forming process. A feed solution and a reservoir solution are provided, each comprising a biopolymer. The feed solution biopolymer and the reservoir solution biopolymer have opposite charges. Droplets of the feed solution are introduced into the reservoir solution, thereby forming via electrostatic complexation a plurality of polymer capsules. At least a portion of the resulting polymer capsules are then encapsulated in a larger polymer capsule via a similar process, wherein the feed solution utilized for the encapsulation process also comprises the formed smaller capsules.
    Type: Application
    Filed: August 14, 2018
    Publication date: June 4, 2020
    Applicant: University of Maryland, College Park
    Inventors: Hyuntaek Oh, Srinivasa R. Raghavan, William E. Bentley, Xi Lu, Jessica Lynn Terrell, So Hyun Ahn
  • Patent number: 10493094
    Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: December 3, 2019
    Assignees: GEL-E, Inc., University of Maryland, College Park, The General Hospital Corporation
    Inventors: Kevin Diehn, Matthew Dowling, Srinivasa R. Raghavan, David R. King
  • Patent number: 10334897
    Abstract: A formulation for coating surfaces, for example gloves, with a tacky film comprises a hydrophobically modified biopolymer, where the hydrophobic modifications of the biopolymer correspond to between 1 and 90% of available functional groups, a plasticizer, and a volatile solvent. The formulation quickly dries into a tacky film that provides an enhanced friction of the surface.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: July 2, 2019
    Assignee: University of Maryland, College Park
    Inventors: Kevin Diehn, Chandamany Arya, Karl Engel, Matthew Furstenburg, Srinivasa R. Raghavan
  • Publication number: 20190192839
    Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.
    Type: Application
    Filed: January 18, 2019
    Publication date: June 27, 2019
    Inventors: Matthew Dowling, Srinivasa R. Raghavan
  • Publication number: 20170326345
    Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.
    Type: Application
    Filed: February 27, 2017
    Publication date: November 16, 2017
    Inventors: Matthew Dowling, Srinivasa R. Raghavan
  • Publication number: 20170326171
    Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.
    Type: Application
    Filed: February 27, 2017
    Publication date: November 16, 2017
    Inventors: Kevin Diehn, Matthew Dowling, Srinivasa R. Raghavan, David R. King
  • Publication number: 20170326169
    Abstract: The present invention provides a novel biomaterial which is a hybrid, self-assembling biopolymeric networked film that is functionalized through hydrophobic interactions with vesicles loaded with bioactive agents. The biomaterial compound is a polymeric network of hydrophobically modified chitosan scaffolds that is taken from solution and formed as a solid film. This solid state film is capable of hydrophobic interactions with the functionalized vesicles. The vesicles include one or more lamellar structures forming one or more nano-compartments that are capable of containing similar or alternative active moieties within. Use of the film results in a degradation of the chitosan scaffold thereby releasing the active moieties within the vesicles from the scaffold. Application of the current invention occurs through various delivery mechanisms and routes of administration as will be described herein.
    Type: Application
    Filed: February 27, 2017
    Publication date: November 16, 2017
    Inventors: Matthew B. Dowling, Srinivasa R. Raghavan, Gregory F. Payne, Chao Zhu
  • Patent number: 9616088
    Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: April 11, 2017
    Assignees: Gel-E, Inc., University of Maryland, College Park, The General Hospital Corporation
    Inventors: Kevin Diehn, Matthew Dowling, Srinivasa R. Raghavan, David R. King
  • Publication number: 20160213704
    Abstract: The present invention provides a novel biomaterial which is a hybrid, self-assembling biopolymeric networked film that is functionalized through hydrophobic interactions with vesicles loaded with bioactive agents. The biomaterial compound is a polymeric network of hydrophobically modified chitosan scaffolds that is taken from solution and formed as a solid film. This solid state film is capable of hydrophobic interactions with the functionalized vesicles. The vesicles include one or more lamellar structures forming one or more nano-compartments that are capable of containing similar or alternative active moieties within. Use of the film results in a degradation of the chitosan scaffold thereby releasing the active moieties within the vesicles from the scaffold. Application of the current invention occurs through various delivery mechanisms and routes of administration as will be described herein.
    Type: Application
    Filed: June 29, 2015
    Publication date: July 28, 2016
    Inventors: Matthew B. Dowling, Srinivasa R. Raghavan, Gregory F. Payne, Chao Zhu
  • Patent number: 9182292
    Abstract: The present invention relates, for example, to a stimulus-indicating device. More particularly, the present invention includes an apparatus for evidencing when a stimulus sensitive product has been exposed to a designated or predetermined stimulus for a certain period of time, and the invention further may include a method for manufacturing aspects of that apparatus.
    Type: Grant
    Filed: March 5, 2008
    Date of Patent: November 10, 2015
    Assignee: Prasidiux, LLC
    Inventors: Rel S. Ambrozy, Jade Litcher, Raymond C. Jones, Chao Zhu, Bani H. Cipriano, Srinivasa R. Raghavan, Jae-Ho Lee
  • Patent number: 9066885
    Abstract: The present invention provides a novel biomaterial which is a hybrid, self-assembling biopolymeric networked film that is functionalized through hydrophobic interactions with vesicles loaded with bioactive agents. The biomaterial compound is a polymeric network of hydrophobically modified chitosan scaffolds that is taken from solution and formed as a solid film. This solid state film is capable of hydrophobic interactions with the functionalized vesicles. The vesicles include one or more lamellar structures forming one or more nano-compartments that are capable of containing similar or alternative active moieties within. Use of the film results in a degradation of the chitosan scaffold thereby releasing the active moieties within the vesicles from the scaffold. Application of the current invention occurs through various delivery mechanisms and routes of administration as will be described herein.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: June 30, 2015
    Assignee: University of Maryland, College Park
    Inventors: Srinivasa R. Raghavan, Gregory F. Payne, Chao Zhu, Matthew B. Dowling
  • Publication number: 20150147468
    Abstract: A formulation for coating surfaces, for example gloves, with a tacky film comprises a hydrophobically modified biopolymer, where the hydrophobic modifications of the biopolymer correspond to between 1 and 90% of available functional groups, a plasticizer, and a volatile solvent. The formulation quickly dries into a tacky film that provides an enhanced friction of the surface.
    Type: Application
    Filed: November 25, 2014
    Publication date: May 28, 2015
    Inventors: Kevin Diehn, Chandamany Arya, Karl Engel, Matthew Furstenburg, Srinivasa R. Raghavan