Microporous Membranes Patents (Class 424/DIG7)
  • Patent number: 6042909
    Abstract: The invention features an empty device for receiving a bioactive agent. The device includes a biocompatible and semi-permeable membrane that defines an enclosed space; the membrane also has at least one end that defines an opening for introducing the bioactive agent into the enclosed space. The device is configured to be placed in an animal.In one embodiment of the invention, the membrane has an inner surface and an outer surface, where the inner surface defines the inner surface, and includes a biocompatible adhesive in the general region of the opening to allow sealing of the opening after the introduction of the bioactive agent into the enclosed space.Another embodiment of the invention includes a biocompatible frame mounted in supporting relationship to the membrane and defining an opening for introducing the bioactive agent into the enclosed space. The frame has greater porosity than the membrane.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: March 28, 2000
    Assignee: Circe Biomedical, Inc.
    Inventors: Karen E. Dunleavy, Timothy J. Perlman, Kerry A. Gagnon, Claudy J. P. Mullon
  • Patent number: 5902603
    Abstract: High capacity drug reservoirs are provided for incorporation into transdermal drug delivery systems. The drug reservoirs are hydrogels formulated from polyurethanes crosslinked with diisocyanate crosslinking agents or cured with radiation in the presence of a photoinitator. Drug loading as high as 65 to 70 wt. % or higher can be achieved by absorbing drug formulation into the reservoir after hydrogel synthesis. Methods for making and using transdermal systems containing such reservoirs are provided as well.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: May 11, 1999
    Assignee: Cygnus, Inc.
    Inventors: Tung-Fen Chen, Chia-Ming Chiang, Janan Jona, Priti Joshi, Asha Ramdas
  • Patent number: 5858385
    Abstract: A novel controlled release device employing microporous membranes with or without a nonporous coating and aqueous-organic partitioning of the bioreactive substances to be delivered is provided. Devices and methods for delivering pharmaceuticals, pest-control substances, hormones, nutrients and fragrances to humans, animals or any environment are also provided.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: January 12, 1999
    Assignee: The Trustees of the Stevens Institute of Technology
    Inventors: Kamalesh K. Sirkar, Stephanie Farrell, Rahul Basu
  • Patent number: 5807917
    Abstract: A composite pressure-sensitive hydrophilic adhesive such as for holding a medical or cosmetic treatment against the skin of a person is composed of a crosslinked polymer and a non-crosslinked polymer and a polar water-miscible solvent having a boiling point above 100.degree. C. at atmospheric pressure. The adhesive has little or no cold flow and can be applied in sheets. An alternate combination of polymers and a method of making both compositions is also disclosed.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: September 15, 1998
    Inventors: Jiri Sulc, Zuzane Krcova
  • Patent number: 5681568
    Abstract: This invention comprises devices and methods for producing a composite microporous membrane specifically tailored to be useful for optimizing the delivery of macromolecules to a therapeutic target.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: October 28, 1997
    Assignee: Cambridge NeuroScience, Inc.
    Inventors: Stanley M. Goldin, Nagesh K. Mahanthappa, Judith Sudhalter, Eric Fine
  • Patent number: 5676962
    Abstract: Injectable microfoam for scleroteraphy. The sclerotherapy of varices is based on the injection of liquid substances capable of suppressing them. The present invention relates to the preparation of sclerosing substances in the form of a microfoam. The microfoam is prepared with sclerosing agents, and is then injected in the vein to be treated, so that the microfoam displaces the blood contained in the vein and provides for the contact of the sclerosing agent with the vascular endothelium, with a predetermined known concentration and during a controllable time.
    Type: Grant
    Filed: February 23, 1995
    Date of Patent: October 14, 1997
    Inventors: Juan Cabrera Garrido, Juan Cabrera Garcia-Olmedo
  • Patent number: 5665391
    Abstract: A cultured, full-thickness integument substitute is disclosed which can be implanted in a patient suffering from severe burns, for example; and consists of a three-dimensional matrix membrane with essentially two surfaces because the length and width are substantially greater than the thickness; the membrane has pores in the area of a first surface thereof which are directly connected to but substantially larger on average than those in the area of the opposite surface of the membrane, and those pores have immobilized within them cells and components of the dermal layer of the integument; the membrane has pores in the area of a second surface thereof which are directly connected to but substantially smaller on average than those in the area of the opposite surface of the membrane, and those pores have immobilized within them cells and components of the epidermal layer of the integument; the membrane also has a lateral pore structure in its internal space which interconnects those pores which pass from one sur
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: September 9, 1997
    Assignee: Spectral Diagnostics Inc.
    Inventor: Peter Lea
  • Patent number: 5585183
    Abstract: A method for preparing liquid-core microcapsules for cell cultures, using a hardening solution containing CaCl.sub.2 and polyethyleneimine to harden gel-core beads before coating them with polylysine solution.
    Type: Grant
    Filed: April 13, 1994
    Date of Patent: December 17, 1996
    Assignee: National Science Council
    Inventor: I-Ming Chu
  • Patent number: 5503848
    Abstract: The present invention relates to a new spongy material consisting essentially of hyaluronic acid or its derivatives. The characteristics of the new pharmaceutical preparations consist in assuring high concentrations of active principle for a long period of time, by exploiting the characteristics of slow release of the active principle.The new pharmaceutical preparations can be utilized advantageously in all the numerous situations of microsurgical practice (in particular the ones relating to ear or in odontostomatology), in which it is necessary to use a substance that can be metabolized by the organism and is capable of making easier flap take, reepithelialization of mucous membranes, stabilization of grafts and filling of cavities.The specific use of the new pharmaceutical preparations is particularly important and useful in the various ear pathologies and in the practice of otologic, otoneurosurgical and odontostomatological microsurgery, such as for instance repair of tympanic perforations.
    Type: Grant
    Filed: August 5, 1992
    Date of Patent: April 2, 1996
    Assignee: Fidia S.p.A.
    Inventors: Alberto Perbellini, Gino Toffano, Aurelio Romeo
  • Patent number: 5288488
    Abstract: A method of controlling the population of a first microorganism at a foliar locus by preferentially enhancing the population of a second microorganism at said locus, comprises applying to the locus an amount of a durable selective habitat enhancer which substantially preferentially potentiates growth of said second microorganism with respect to said first microorganism. The durable selective habitat enhancer preferably comprises a substantially water-insoluble, weather resistant polymeric substrate and a binder which increases the durability of the habitat enhancer. The second microorganism can be endogenous to the foliar locus or exogenously applied. Chitin and cellulose are preferred habitat enhancers.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: February 22, 1994
    Assignee: Auburn University
    Inventors: Paul A. Backman, Rodrigo Rodriguez-Kabana, Nancy M. Kokalis
  • Patent number: 5091175
    Abstract: A pharmaceutical composition useful for treating hypercholesterolemia comprising a bile acid sequestrant resin such as cholestyramine and cholestipol maintained in a semipermeable water-insoluble material; wherein said semipermeable material enables bile acids from the digest tract to contact and bind to said resin while preventing substances having a higher molecular weight than bile acids from contacting said resin material. A method for treating hypercholesterolemia using the inventive composition is also disclosed.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: February 25, 1992
    Assignee: Erbamont Inc.
    Inventors: Anthony R. Imondi, Larry M. Hagerman
  • Patent number: 5071657
    Abstract: A device for transdermal administration of active medicinal agents is based on the active medicinal agent dissolved to an extent of at least 50% in a nonflowable, physiologically acceptable gel, which latter is distributed in a microdisperse mode in a crosslinked silicone elastomer.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: December 10, 1991
    Assignee: Schering Aktiengesellschaft
    Inventors: Horst Oloff, Johannes-Wilhelm Tack, Fred Windt, Ingfried Zimmermann
  • Patent number: 4968733
    Abstract: A process produces microporous powders or shaped articles, in particular membranes in the form of flat films, tubular films or hollow fibers, which may be used for controlled release of an active compound, for dialysis, gas separation, ultrafiltration or microfiltration, from polyvinylidene fluoride and/or polyphenylene sulfide and/or polysulfone and/or polyacrylonitrile and/or ethylene/vinyl alcohol copolymer and/or ethylene/chlorotrifluoroethylene copolymer and/or polyethersulfone and/or polyether-imide and/or polymethyl methacrylate and/or polycarbonate and/or cellulose triacetate. The process utilizes phase separation by means of thermally induced triggering or triggering induced by a non-solvent of a solution of the polymer in a mixture containing .epsilon.-caprolactam as the essential dissolving constituent. The solution may be formed before the phase separation is triggered.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: November 6, 1990
    Assignee: Akzo N.V.
    Inventors: Heinz-Joachim Muller, Friedbert Wechs
  • Patent number: 4954381
    Abstract: A membrane of defined pore structure and controlled pore diameter and a method of preparing the membrane which comprises dispersing in a water soluble polymer solution (A) an organic polymer solution (B), the water-soluble polymer solution (A) being a non-solvent for the polymer solution (B), to form micro-spherical droplets of the polymer solution (A) which are enveloped by a solid phase consisting of a coagulated or cross-linked polymer solution (B); evenly casting the dispersion on a flat surface; and evaporating the solvent for the polymer solution (B) to form a microporous membrane comprised of the polymer (B), the porosity, pore size, and void volume of the microporous membrane being a function of the polymer (A) concentration, the microsphere dimensions and the temperature and evaporation rate.
    Type: Grant
    Filed: March 21, 1988
    Date of Patent: September 4, 1990
    Assignee: The Research Foundation of the State University of New York
    Inventors: Israel Cabasso, Moshe Levy
  • Patent number: 4904260
    Abstract: By implanting two prosthetic disc capsules side-by-side into a damaged disc of a human spine, both height and motion, including front-to-back bending, can be maintained. Each prosthetic disc capsule has a bladder enclosing a fluid containing a therapeutic material that is slowly diffusible through a semi-permeable membrane of the bladder. The fluid filling the semi-permeable membrane preferably is an aqueous solution that has gel-like properties that afford a viscosity and velocity-shear behavior imitating the natural rheology of intradiscal nuclear tissue. Those properties are obtained when the aqueous solution is of a mucopolysaccharide such as hyaluronic acid or soldium hyaluronate.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: February 27, 1990
    Assignee: Cedar Surgical, Inc.
    Inventors: Charles D. Ray, Terry P. Corbin
  • Patent number: 4818542
    Abstract: Controlled release drug delivery systems comprised of spherical microporous polymeric network of interconnecting channels containing pore incorporated drugs or other agents wherein the drugs or agents are confined within the pore channel are described. Also disclosed are processing parameters in connection with the novel method of the invention for obtaining drug delivery systems especially suited for parenteral as well as oral administration.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: April 4, 1989
    Assignee: The University of Kentucky Research Foundation
    Inventors: Patrick P. DeLuca, Motoko Kanke, Toyomi Sato, Hans G. Schroeder
  • Patent number: 4794002
    Abstract: A process for surface modifying a variety of polymeric support surfaces is disclosed in which a predetermined modifying polymer is irreversibly absorbed onto essentially all the surfaces of the support polymer accessible to the modifying polymer. The modifying polymer is selected to impart the desired surface characteristics to the modified polymeric surface.
    Type: Grant
    Filed: September 5, 1986
    Date of Patent: December 27, 1988
    Assignee: Monsanto Company
    Inventors: Jay M. Henis, Mary K. Tripodi, Donald I. Stimpson
  • Patent number: 4771004
    Abstract: Provided is a novel barrier membrane and a method using the barrier membrane for testing the transdermal penetration behavior of a bioactive agent. The method employs shed snake skin as the model barrier membrane. In particular, the method comprises the steps of providing a dose of a donor formulation containing the bioactive agent, and a receptor solution, with a barrier membrane of shed snake skin separating the donor formulation and receptor solution. The receptor solution is then serially sampled and assayed in order to determine the concentration of the bioactive agent in the receptor solution. The use of the shed snake skin has been found to provide reproducible and uniform results as a model barrier membrane. As well, the shed snake skin offers the advantages of being readily available and storable for an extended period of time.
    Type: Grant
    Filed: August 29, 1986
    Date of Patent: September 13, 1988
    Assignee: IPRX, Inc.
    Inventor: Takeru Higuchi
  • Patent number: 4719112
    Abstract: Foam capsules with telescopically engaged body and cap portions, also known as hard shell capsules, having a special wall structure, obtained by a microdispersion of a gas in a gelatin solution.The capsule body and cap portions are formed by dipmolding the film-forming mixture obtained by a microdispersion of the gas in a gelatin solution; optionally with the inclusion of a plasticizer and/or coloring agent, and/or flavoring agent, and/or foam stabilizer, and/or gelatin extender.By a suitable choice of the gas proportion in the capsule wall and its micronization level, it is possible, within certain limits, to control the capsule wall disintegration speed and its opacity. In addition, inclusion of gas bubbles into the capsule wall lowers the gelatin content for a foam capsule and provides energy saving during the process due to a faster drying of the wall, thereby providing lower cost prices for the production of pharmaceutically acceptable capsules.
    Type: Grant
    Filed: August 19, 1985
    Date of Patent: January 12, 1988
    Assignee: Warner-Lambert Company
    Inventors: Jean P. Mayer, Fritz Wittwer
  • Patent number: 4666704
    Abstract: A controlled release implant composition which includes a core comprising a macromolecular drug and a water insoluble polymer and a homogeneous outer polymeric membrane formed by coating said core with an organic solution of a water insoluble polymer and a water soluble pore-forming agent.
    Type: Grant
    Filed: May 24, 1985
    Date of Patent: May 19, 1987
    Assignee: International Minerals & Chemical Corp.
    Inventors: Mohamad D. Shalati, Kallidaikurichi N. Sivaramakrishnan
  • Patent number: 4647536
    Abstract: Viable biomaterial such as animal cells, plant cells, bacteria, algae or fungi are immobilized with retained ability of growth by encapsulation in polymer beads. Encapsulation is carried out by adding the biomaterial to an aqueous solution of a polymer such as agar, agarose, carrageenan, chitosan, gelatin, collagen or fibrinogen, dispersing the solution in a water-insoluble dispersion medium such as soybean oil, tri-n-butylphosphate, liquid silicone, paraffin oil or phthalic acid dibutylester and allowing the polymer to gel.
    Type: Grant
    Filed: November 8, 1983
    Date of Patent: March 3, 1987
    Inventors: Klaus Mosbach, Kjell Nilsson
  • Patent number: 4637905
    Abstract: A process for preparing polylactide (PLA) microcapsules is described and involves dissolving PLA in a mixture of two miscible organic liquids, the higher vapor pressure liquid having solvent power for PLA and the second having little or no solvent power for PLA. The solution is prepared such that it is near its saturation point for PLA. Encapsulation of dispersed core material is achieved by vaporizing the liquid having solvent power for PLA causing phase separation of the PLA, then transferring the separated dispersion to an organic liquid having no solvent power for the PLA in order to harden the encapsulating coating. The disclosed process enables forming true microcapsules or reservoir-type devices encapsulating liquid core material particularly aqueous liquid core material and oil in water emulsion or suspensions.
    Type: Grant
    Filed: April 11, 1985
    Date of Patent: January 20, 1987
    Assignee: Batelle Development Corporation
    Inventor: David L. Gardner
  • Patent number: 4585652
    Abstract: A method is disclosed for the controlled delivery of an ionic bioactive chemical into a physiological medium comprising ionically binding the chemical to redox sites on a charged polymer and releasing the bound chemical into the medium by neutralizing the charge on the polymer.
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: April 29, 1986
    Assignee: Regents of the University of Minnesota
    Inventors: Larry L. Miller, Ronald L. Blankespoor, Baruch Zinger
  • Patent number: 4582799
    Abstract: Disclosed is a process for recovering nonsecreted substances produced by cells. The process eliminates some of the high molecular weight contaminants thereby simplifying the purification process. The cells are encapsulated within a semipermeable membrane having properties which permit rapid passage of the relatively low molecular weight substances of interest but retard or prevent passage of higher molecular weight contaminants. The encapsulated cells are suspended in a culture medium and undergo normal cell growth and mitosis. The encapsulated cell culture grows to substantially fill the capsules but not rupture them. The cell membrane is then lysed without disrupting the capsule membrane. The permeability of the capsule membrane is such that the substances of interest diffuse rapidly through the capsule membrane into the extracapsular fluid while the higher molecular weight contaminants and cell fragments are retained within the capsule.
    Type: Grant
    Filed: April 15, 1983
    Date of Patent: April 15, 1986
    Assignee: Damon Biotech, Inc.
    Inventor: Allan P. Jarvis, Jr.
  • Patent number: 4559054
    Abstract: A drug release device employing a block copolymer of poly(ether-urethane)/poly(dimethyl siloxane) is useful for dispensing lipophilic drugs at a high controlled rate for prolonged periods of time. The initial "burst effect" of drug release experienced with prior drug release devices is eliminated or at least substantially reduced with these devices.
    Type: Grant
    Filed: August 9, 1984
    Date of Patent: December 17, 1985
    Assignee: Research Corporation
    Inventor: Stephen D. Bruck
  • Patent number: 4557955
    Abstract: The invention relates to films and tubular structures which are selectively permeable to liquids and gases which are based on a copolymer composed of a copolymerized fluorinated olefin, copolymerized vinyl acetate and, optionally, a copolymerized olefin. It is possible for the acetate groups of the copolymer to have been saponified to form OH groups. The films or tubular structures have in each case an inherent, latent capacity for modifying their structure and are at the same time oleophobic and oleophilic. The invention also embraces processes for the preparation of the shaped articles described and processes for modifying their structure. The invention also relates to the use of shaped articles according to the invention.
    Type: Grant
    Filed: July 27, 1982
    Date of Patent: December 10, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Walter Seifried, Wolfgang Michel, Jurgen Kuhls, Jurgen Wildhardt
  • Patent number: 4557749
    Abstract: Device for conditioning hydrosoluble fertilizers and/or hydrosoluble products usable in agriculture, wherein it comprises a sealed container, whereof at least one of the walls is constituted by a hydrophobic polymer diaphragm having hydrophilic inclusions, said container containing the fertilizers and/or products.A process for preparing a hydrophobic polymer diaphragm containing hydrophilic inclusions and usable in the conditioning device consists of preparing a hydrophobic polymer powder grafted by hydrophilic monomers and bringing this powder into the form of a diaphragm by different processes performed hot.
    Type: Grant
    Filed: September 21, 1982
    Date of Patent: December 10, 1985
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Jeanne Berthet, Marie-Francoise Blin, Gilbert Gaussens, Jean R. Noaillac
  • Patent number: 4532123
    Abstract: Dual Microcapsules are disclosed. The outer membrane encapsulates a liquid having one or more smaller microcapsules (Mini-Microcapsules) suspended therein. The Mini-Microcapsules contain a conjugate or a reaction product of a Drug which diffuses into the liquid in which Mini-Microcapsules are suspended. The suspending liquid contains an enzyme which reacts with Drug complex or reaction product to regenerate or release the Drug. The drug diffuses through the outer membrane into a host.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: July 30, 1985
    Assignee: Battelle Development Corporation
    Inventor: David L. Gardner
  • Patent number: 4501835
    Abstract: A novel composition of matter comprising a polyacrylic acid/chitosan complex. This complex is particularly useful as a membrane or filter.
    Type: Grant
    Filed: November 9, 1983
    Date of Patent: February 26, 1985
    Assignee: Polaroid Corporation
    Inventor: Carl M. Berke
  • Patent number: 4423099
    Abstract: Non-uniform water-insoluble interpenetrating polymer blend compositions comprising a first permeable water swellable polymer substrate interpenetrated in a gradient substantially normal to the substrate surface by a second less permeable condensation polymer to form a diffusion rate controlling membrane therein. Such compositions are useful as polymers with reduced permeabilities for water and organic solvents and therefore for the controlled delivery of active ingredients such as fragrances and bio-affecting agents into air or aqueous environments, or in membrane separation processes.
    Type: Grant
    Filed: July 28, 1980
    Date of Patent: December 27, 1983
    Assignee: Ciba-Geigy Corporation
    Inventors: Karl F. Mueller, Sonia J. Heiber
  • Patent number: 4409331
    Abstract: Disclosed is a system and process for producing substances produced in cells such as antibodies and biological response modifiers. Cells which produce the substance of interest are encapsulated within semipermeable membranes having an upper limit of permeability sufficient to allow traverse of ions, amino acids and other cell nutrients and then suspended in a culture medium. Serum components or other high molecular weight materials needed for ongoing viability and normal in vitro metabolism of certain types of cells may be included within the intracapsular volume and may be excluded from the extracapsular medium by limiting the permeability of the membranes. The substance of interest collects either in the intracapsular volume or the extracapsular medium, depending on the degree of permeability of the membranes and on the molecular weight of the substance.
    Type: Grant
    Filed: April 28, 1982
    Date of Patent: October 11, 1983
    Assignee: Damon Corporation
    Inventor: Franklin Lim
  • Patent number: 4377010
    Abstract: A biocompatible surgical device comprises at least at its surface a hydrophilic thermoplastic graft copolymer which is an ethylenic carboxylic acid, selected from acrylic acid and alkyl substituted acrylic acids graft copolymerized onto a base polymer. The base polymer is preferably selected from polyolefins, especially polyethylene and polypropylene, partially and fully fluorinated polyolefins, especially polytetrafluoroethylene and polyetherurethanes.Graft copolymerization of the monomers to the base polymer is initiated preferably by ionizing radiations, especially gamma radiation. The reaction takes place preferably in an aqueous solution and in the presence of a homopolymerization inhibitor such as ferrous sulphate or potassium ferricyanide.The base polymer may be graft copolymerized throughout its entire thickness or to a known depth in one or more of its surfaces. The former material exhibits high elastic properties while the latter exhibits a low elasticity and low moduli.
    Type: Grant
    Filed: October 31, 1979
    Date of Patent: March 22, 1983
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Peter J. Fydelor, David E. M. Taylor
  • Patent number: 4322311
    Abstract: A process for producing microcapsules of controlled porosity containing a chemically active core material. A core material such as a biologically active material and a first monomer in aqueous solution are emulsified in a hydrophobic solvent. A monomer complementary to the first and soluble in the continuous, hydrophobic phase of the emulsion is added to initiate interfacial polymerization about the aqueous droplets. During the course of the reaction, the affinity of the continuous phase for the first monomer is varied by adding a solvent to the continuous phase to vary its polarity. The continuous phase may be relatively nonpolar at the outset and a polar solvent may be added to increase its affinity for the first monomer, or it may be relatively polar at the outset and a nonpolar (or less polar) solvent may be added.
    Type: Grant
    Filed: April 25, 1980
    Date of Patent: March 30, 1982
    Assignee: Damon Corporation
    Inventors: Franklin Lim, Richard D. Moss
  • Patent number: 4251387
    Abstract: Techniques for producing semipermeable microcapsules by interfacial polymerization are disclosed. The material to be encapsulated and a hydrophilic monomer are emulsified within a hydrophobic continuous phase. Polymerization is initiated by dissolving a second monomer in the continuous phase, and occurs only at the interface of the emulsion to result in the formation of macroporous, poorly defined capsule membranes. Next, the affinity of the continuous phase for the hydrophilic monomer is varied by altering the polarity of the continuous phase. This step is accomplished either by isolating and resuspending the raw capsules in a fresh continuous phase of different polar character, or by mixing a second solvent with the continuous phase. By controlling the affinity and the concentration of the second monomer, it is possible to produce microcapsules having uniform capsule membranes and a selected upper limit of permeability.
    Type: Grant
    Filed: April 17, 1979
    Date of Patent: February 17, 1981
    Assignee: Damon Corporation
    Inventors: Franklin Lim, Richard D. Moss
  • Patent number: 4174277
    Abstract: Microporous anionic exchange and non-ionic adsorbent resins which are capable of adsorbing an antibiotic and which have been coated with a non-ionic detergent are disclosed. When contacted with bacterially infected body-fluid specimens, the disclosed resins remove antibiotics from the specimen while exhibiting diminished bacterial adsorption. A combination of a disclosed detergent-coated non-functional adsorbent resin with a cationic resin removes other bacterial inhibitors, as well as antibiotics, from bacterially infected body fluid specimens while permitting the bacteria to remain in the specimens. By removing bacterial inhibitors while sparing the bacteria, the disclosed resins make possible rapid isolation and identification of an infecting organism.
    Type: Grant
    Filed: September 25, 1978
    Date of Patent: November 13, 1979
    Inventors: Joseph L. Melnick, Craig Wallis
  • Patent number: 4145304
    Abstract: Microporous anionic exchange and non-ionic adsorbent resins which are capable of adsorbing an antibiotic and which have been coated with a non-ionic detergent are disclosed. When contacted with bacterially infected body-fluid specimens, the disclosed resins remove antibiotics from the specimen while exhibiting diminished bacterial adsorption. A combination of a disclosed detergent-coated non-functional adsorbent resin with a cationic resin removes other bacterial inhibitors, as well as antibiotics, from bacterially infected body fluid specimens while permitting the bacteria to remain in the specimens. By removing bacterial inhibitors while sparing the bacteria, the disclosed resins make possible rapid isolation and identification of an infecting organism.
    Type: Grant
    Filed: December 2, 1977
    Date of Patent: March 20, 1979
    Inventors: Joseph L. Melnick, Craig Wallis
  • Patent number: 3985840
    Abstract: Microporosity is introduced into a membrane capable of retaining a liquid by (a) forming a single homogeneous liquid phase comprising a first material and a second material, at a temperature above the melting points of said materials, said first material being incompatible with said second material when said liquid phase is cooled to room temperature, the volume contraction ratio being at least about 1.2, and (b) permitting the liquid phase to cool to room temperature, whereby said first material separates out as a dispersed solid phase and creates micropores which extend completely through said membrane.
    Type: Grant
    Filed: December 20, 1973
    Date of Patent: October 12, 1976
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: David A. Hofacker
  • Patent number: 3977992
    Abstract: The disclosed substantially spherical capsules are particularly adapted for containing a liquid and have permeable or semi-permeable capsule walls. The capsule walls can comprise a first crystalline phase, an amorphous phase which ordinarily is intimately associated with the crystalline phase, and, preferably, a dispersed (discontinuous) second crystalline or semi-crystalline phase such as a wax. These capsules have the ability to release a solute by an effect resembling osmosis and to release a liquid by a transmission and evaporation mechanism.
    Type: Grant
    Filed: November 8, 1971
    Date of Patent: August 31, 1976
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: David A. Hofacker