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  Polysaccharide compositions for use in tissue augmentationUSPTO Application #: 20070184087Title: Polysaccharide compositions for use in tissue augmentation Abstract: A composition of matter and method for preparation of a tissue augmentation material. A polysaccharide gel composition is prepared with a programmable rheology for a particular selected application. The method includes preparing a polymeric polysaccharide in a buffer to create a polymer solution or gel suspending particles in the gel and selecting a rheology profile for the desired tissue region. (end of abstract) Agent: Foley & Lardner LLP - Chicago, IL, US Inventors: Robert Voigts, Dale Devore USPTO Applicaton #: 20070184087 - Class: 424423000 (USPTO) Related Patent Categories: Drug, Bio-affecting And Body Treating Compositions, Preparations Characterized By Special Physical Form, Implant Or Insert, Surgical Implant Or Material The Patent Description & Claims data below is from USPTO Patent Application 20070184087. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED PATENT APPLICATION [0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 11/348,028, filed Feb. 6, 2006 and incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates generally to tissue augmentation, and more particularly to injection of resorbable, biocompatible, solid composites to correct and augment soft tissue defects with specific application for cosmetic augmentation of tissues. BACKGROUND OF THE INVENTION [0003] There are a number of non-resorbable, particle-based compositions used for permanent correction or augmentation of soft tissue defects or augmentation for cosmetic purposes. Each composition is associated with certain advantages and disadvantages. [0004] Silicone gel was frequently used to treat dermal defects, such as wrinkles, folds, and acne scars in the 1970's and 1980's but has since been prohibited from use in these applications. Silicone was frequently associated with chronic inflammation, granuloma formation, and allergic reactions. [0005] Teflon paste is a suspension of polytetrafluoroethylene particles in glycerin. This composition was primarily used for vocal fold augmentation and was associated with granuloma formation. [0006] Bioplastics composed of polymerized silicone particles dispersed in polyvinylpyrrolidone. This composition has been withdrawn from commercial application due to frequent chronic inflammation and tissue rejection. [0007] Polymethylmethacrylate (PMMA) microspheres having a diameter of 20-40 .mu.m and suspended in a bovine collagen dispersion have been described by Lemperle (U.S. Pat. No. 5,344,452). This composition has been used as a biocompatible alloplastic for tissue augmentation. Since the composition contains collagen from a bovine source, skin testing is required. In addition, the composition is associated with sterilization challenges; the bovine collagen dispersion is damaged by standard terminal sterilization techniques, including heat and gamma irradiation. PMMA is also labile to heat sterilization conditions. [0008] Sander, et.al. (U.S. Pat. No. 5,356,629) describes bone repair compositions comprised of a plurality of biocompatible particles dispersed in a matrix selected from a group consisting of hyaluronic acid, cellulose ethers, collagen and others. The biocompatible particles include suitable nonbioabsorbable material derived from xenograft bone, homologous bone, autologous bone, hydroxyapatite and polymethylmethacrylate. Cellulose ethers include hydroxypropylmethylcellulose, methylcellulose, and carboxymethylcellulose and mixtures thereof. Sodium carboxymethylcellulose is the preferred form of carboxymethylcellulose. Biocompatible particles ranged from about 64% to 94% by weight. Matrix components ranged from about 6% to about 35% by weight. Compositions were formulated into putty for bone repair. [0009] Lawin, et.al. (U.S. Pat. No. 5,451,406) describes a biocompatible composition consisting of stable microparticles carried in a lubricative suspension, solution, fluid or gel. The microparticles are carbon-coated substrate particles comprised of stainless steel, titanium, titanium alloys and their oxides. The carrier is selected from a group comprised of hyaluronic acid, polyvinylpyrrolidone, dextran, glycerol, polyethylene glycol, succinylated collagen, liquid collagen or other polysaccharides. The carrier is preferably comprised of polymeric chains of .beta.-D glucose. Compositions are intended to strengthen bulk-up, or otherwise augment tissue sites. [0010] Injectable suspensions of bio-active glass particles in a dextran derivative have been described by Hench, et.al. (U.S. Pat. No. 6,190,684). Smooth or rough particles of bioactive glass may be spherical or irregular and smooth or rough and range in size from about 10 to 350 microns. The viscous dextran can be mixed with bioactive glass particles in a ratio of about 35:65 to about 65:35 by weight glass to dextran to form an injectable composite. The composition may be injected using 16 to 23 gauge needles for tissue augmentation. [0011] Vogel, et.al., (U.S. Pat. Nos. 6,436,424 and 6,660,301) describe injectable, swellable microspheres. The microspheres comprise sodium acrylate polymer, acrylamide polymer, acrylamide derivative polymer or copolymer, sodium acrylate and vinyl alcohol copolymer, vinyl acetate and acrylic acid ester copolymer, vinyl acetate and methyl maleate copolymer, isobutylene-maleic anhydride crosslinked copolymer, starch-acrylonitrile graft copolymer, crosslinked sodium polyacrylate polymer, crosslinked polyethylene oxide, or mixtures thereof. The compositions contain microspheres in amounts ranging from about 10% to about 90% by weight and the biocompatible carrier from about 10% to about 90% by weight. [0012] Compositions containing resorbable particles dispersed in a polysaccharide carrier have been previously described. [0013] Synthetic, resorbable microspheres composed of polylactides, such as polylactic acids (PLA), polyglycolides (PGA) or copolymers of PLA and PGA have been dispersed in a carrier gel (U.S. Pat. No. 6,716,251). The carrier gels included preparations of carboxymethylcellulose (CMC) or hydroxypropylmethylcellulose (HPMC) or synthetic hyaluronic acid. Such compositions were prepared for use as subcutaneous or dermal injection, intended for use in humans in reparative or plastic surgery and in aesthetic dermatology. Concentrations of CMC ranged from 0.1% to 7.5%, preferably from 0.1% to 5%. Mixtures of PLA in CMC were freeze dried and sterilized by gamma irradiation. [0014] Hubbard (U.S. Pat. Nos. 5,922,025; 6,432,437; 6,537,574; and 6,558,612) describes an implantable or injectable soft tissue augmentation material comprised of substantially spherical, biocompatible, substantially non-resorbable ceramic particles suspended in biocompatible, resorbable fluid lubricant comprised of aqueous glycerin and sodium carboxylmethylcellulose. Ceramic particles in the composition can vary from 15% to 50% by volume. Preparations having more than 50% ceramic particles become viscous and care must be taken to select an injection apparatus. Compositions containing ceramic particles of 35% to 45% can easily be injected through an 18 gauge needle. A 28 gauge needle may be used depending on the tissue sites for augmentation. Sterilization was accomplished by autoclaving at temperatures of about 115.degree. C. to 130.degree. C., and preferably about 120.degree. C. to 125.degree. C. [0015] Tucker, et.al. (U.S. Pat. No. 6,461,630) describes terminally sterilized osteogenic devices intended for implantation to induce bone formation. The devices contains a biologically active, osteogenic protein in a carrier comprised of collagen, hydroxyapatite, tricalcium phosphate, combinations of collagen with hydroxyapatite, tricalcium phosphate, all of which may be supplemented with carboxymethylcellulose. Sterilization was accomplished by gamma irradiation after drying the composition comprised of osteogenic protein and biocompatible carrier. [0016] Ronan, et.al. (U.S. Pat. No. 6,387,978) describes shaped-medical devices, e.g. stents, having improved mechanical properties and structural integrity. The devices comprise shaped polymeric hydrogels which are both ionically and non-ionically crosslinked and which exhibit improved structural integrity after selective removal of the crosslinking ions. Process for making such devices are also disclosed wherein an ionically crosslinkable polymer is both ionically and non-ionically crosslinked to form a shaped medical device. When implanted in the body, selective in-vivo stripping of the crosslinking ions produces a softer, more flexible implant. [0017] Asius, et.al., (U.S. Pat. No. 6,716,251) describe implants for subcutaneous or intradermal injection. The implants contain microparticles of lactic acid and glycolic acid in a gel composed of 0.1-7.5% by weight carboxymethylcellulose. Microparticles range in size from 5 to less than 150 micrometers and in a concentration from 50 to 300 g/l. [0018] Boume, et.al., (U.S. Pat. No. 7,131,997) describes a method for treating tissue by placing spherical polymer particles in tissue. The particles composed of polyvinyl alcohol can include a polysaccharide such as alginate. [0019] As can be seen from the prior art, carboxymethylcellulose and other polysaccharides are examples of material used in gel or solution form for a variety of medical and non-medical applications. Sodium carboxymethylcellulose ("CMC") is cellulose reacted with alkali and chloroacetic acid. It is one of the most abundant cellulose polymers available. It is water soluble and biodegradable and used in a number of medical and food applications. It is also commonly used in textiles, detergents, insecticides, oil well drilling, paper, leather, paints, foundry, ceramics, pencils, explosives, cosmetics and adhesives. It functions as a thickening agent, a bonder, stabilizer, water retainer, absorber, and adhesive. [0020] A number of literature references describe carboxymethylcellulose and other ionic polysaccharides as being viscoelastic and pseudoplastic. See, for example: (Andrews G P, Gorman S P, Jones D S., Rheological Characterization of Primary and Binary Interactive Bioadhesive Gels Composed of Cellulose Derivatives Designed as Ophthalmic Viscosurgical Devices, Biomaterials. 2005 February; 26 (5):571-80; Adeyeye M C, Jain A C, Ghorab M K, Reilly W J Jr, Viscoelastic Evaluation of Topical Creams Containing Microcrystalline Cellulose/sodium Carboxymethyl Cellulose as Stabilizer, AAPS PharmSciTech. 2002; 3 (2):E8; Lin S Y, Amidon G L, Weiner N D, Goldberg A H., Viscoelasticity of Anionic Polymers and Their Mucociliary Transport on the Frog Palate, Pharm. Res. 1993, March: 10 (3): 411-417; Vais, A E, Koray, T P, Sandeep, K P, Daubert, C R. Rheological Characterization of Carboxymethylcellulose Solution Under Aseptic Processing Conditions, J. Food Science, 2002. Process Engineering 25: 41-62). [0021] The effects of various parameters on rheology of sodium CMC have been described. Viscosity increases with increasing concentration, and CMC solutions are pseudoplastic and viscoelastic. Exposure to heat results in a reduction in viscosity and effects are reversible under normal conditions. After long periods of time, CMC will degrade at elevated temperatures with permanently reduced viscosity. For example, moderate MW (Aqualon 7 L) CMC heated for 48 hours at 180.degree. F. will lose 64% of viscosity. CMC is relatively stable to changes in pH, and effects of pH on viscosity are minimal from pH 7-9. There is some loss of viscosity above 10 and some increase below 4. Salts may also affect rheology of CMC. Monovalent cations interact to form soluble salts. If CMC is dissolved in water and then salts are added, there is little effect on viscosity. If CMC is added dry to salt solution, viscosity can be depressed. Polyvalent cations will not generally form crosslinked gels. Viscosity is reduced when divalent salts added to CMC solution and trivalent salts precipitate CMC. Continue reading... Full patent description for Polysaccharide compositions for use in tissue augmentation Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Polysaccharide compositions for use in tissue augmentation patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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