532 results about "Polyhydroxyalkanoates" patented technology

Devices formed of or including biocompatible polyhydroxyalkanoates are provided with controlled degradation rates, preferably less than one year under physiological conditions. Preferred devices include sutures, suture fasteners, meniscus repair devices, rivets, tacks, staples, screws (including interference screws), bone plates and bone plating systems, surgical mesh, repair patches, slings, cardiovascular patches, orthopedic pins (including bone filling augmentation material), adhesion barriers, stents, guided tissue repair / regeneration devices, articular cartilage repair devices, nerve guides, tendon repair devices, atrial septal defect repair devices, pericardial patches, bulking and filling agents, vein valves, bone marrow scaffolds, meniscus regeneration devices, ligament and tendon grafts, ocular cell implants, spinal fusion cages, skin substitutes, dural substitutes, bone graft substitutes, bone dowels, wound dressings, and hemostats. The polyhydroxyalkanoates can contain additives, be formed of mixtures of monomers or include pendant groups or modifications in their backbones, or can be chemically modified, all to alter the degradation rates. The polyhydroxyalkanoate compositions also provide favorable mechanical properties, biocompatibility, and degradation times within desirable time frames under physiological conditions.

Devices formed of or including biocompatible polyhydroxyalkanoates are provided with controlled degradation rates, preferably less than one year under physiological conditions. Preferred devices include sutures, suture fasteners, meniscus repair devices, rivets, tacks, staples, screws (including interference screws), bone plates and bone plating systems, surgical mesh, repair patches, slings, cardiovascular patches, orthopedic pins (including bone filling augmentation material), adhesion barriers, stents, guided tissue repair / regeneration devices, articular cartilage repair devices, nerve guides, tendon repair devices, atrial septal defect repair devices, pericardial patches, bulking and filling agents, vein valves, bone marrow scaffolds, meniscus regeneration devices, ligament and tendon grafts, ocular cell implants, spinal fusion cages, skin substitutes, dural substitutes, bone graft substitutes, bone dowels, wound dressings, and hemostats. The polyhydroxyalkanoates can contain additives, be formed of mixtures of monomers or include pendant groups or modifications in their backbones, or can be chemically modified, all to alter the degradation rates. The polyhydroxyalkanoate compositions also provide favorable mechanical properties, biocompatibility, and degradation times within desirable time frames under physiological conditions.

Methods for the biosynthesis of polyhydroxyalkanoate homopolymers and copolymers are described. In a preferred embodiment, the polymers have a single mode molecular weight distribution, and more preferably have a distribution of between about 2 and about 4, and most preferably about 2.1 or 2.5.

Environmentally degradable melt spun fibers comprising a polyhydroxyalkanoate copolymer and a polylactic acid polymer or copolymer are disclosed. A preferred configuration of the present invention is directed to environmentally degradable fibers comprising a sheath / core structure where the core comprises a biodegradable polyhydroxyalkanoate copolymer and the sheath comprises a polymer or copolymer of polylactic acid. Nonwoven webs and disposable articles comprising the environmentally degradable fibers are also disclosed.

Biocompatible polyhydroxyalkanoate compositions with controlled degradation rates have been developed. In one embodiment, the polyhydroxyalkanoates contain additives to alter the degradation rates. In another embodiment, the polyhydroxyalkanoates are formed of mixtures of monomers or include pendant groups or modifications in their backbones to alter their degradation rates. In still another embodiment, the polyhydroxyalkanoates are chemically modified. Methods for manufacturing the devices which increase porosity or exposed surface area can be used to alter degradability. For example, as demonstrated by the examples, porous polyhydroxyalkanoates can be made using methods that creates pores, voids, or interstitial spacing, such as an emulsion or spray drying technique, or which incorporate leachable or lyophilizable particles within the polymer. Examples describe poly(4HB) compositions including foams, coatings, meshes, and microparticles. As demonstrated by the examples, these polyhydroxyalkanoate compositions have extremely favorable mechanical properties, as well as are biocompatible and degrade within desirable time frames under physioogical conditions. These polyhydroxyalkanoate materials provide a wider range of polyhydroxyalkanoate degradation rates than are currently available. Methods for processing these materials, particularly for therapeutic, prophylactic or diagnostic applications, or into devices which can be implanted or injected, are also described.

Polyhydroxyalkanoates (PHAs) from which pyrogen has been removed are provided for use in numerous biomedical applications. PHAs which have been chemically modified to enhance physical and / or chemical properties, for targeting or to modify biodegradability or clearance by the reticuloendothelial system (RES), are described. Methods for depyrogenating PHA polymers prepared by bacterial fermentation processes are also provided, wherein pyrogens are removed from the polymers without adversely impacting the polymers' inherent chemical structures and physical properties. PHAs with advantageous processing characteristics, including low melting points and / or solubility in non-toxic solvents, are also described. PHAs are provided which are suitable for use in in vivo applications such as in tissue coatings, stents, sutures, tubing, bone and other prostheses, bone or tissue cements, tissue regeneration devices, wound dressings, drug delivery, and for diagnostic and prophylactic uses. Properties which are selected for include degradability, elasticity, inclusion of functional groups or derivatized groups, which can in turn be used to attach targeting agents, and bioadhesion.

The present invention provides polymers made by genetically engineering microorganisms for making a self-retaining suture. In an embodiment of the present invention the genetically engineering microorganisms synthesize polyhydroxyalkanoate (PHA) polymers. In an alternate embodiment of the invention, the genetically engineering microorganisms synthesize polybetahydroxybutyrate (PHB) polymers. In an alternative embodiment of the invention, the self-retaining sutures can be made from a copolymer such as polyhydroxybutyratevalerate (PHBV), where the genetically engineering microorganisms produces PHA polymers as the monofilament base material and a different genetically engineering microorganisms produces polyhydroxybutyratevalerate (PHBV) polymers. In various embodiments of the invention, recombinant expressed self-retaining suture materials have a melting point in the range from between approximately 40° C. to approximately 180° C. In various embodiments of the invention, recombinant expressed self-retaining suture materials have extension-to-break strength of between approximately 8% and approximately 42%.

Polyhydroxyalkanoate materials are provided which are suitable for repair of soft tissue, augmentation, and as viscosupplements in animals, particularly humans. The materials comprise liquid polyhydroxyalkanoate polymer compositions or polyhydroxyalkanoate microdispersions. Devices also are provided for storage and delivery of the polyhydroxyalkanoate compositions in vivo. Methods are provided for repairing or augmenting soft tissue in animals using the materials. In a preferred embodiment, the method include the steps of (a) selecting the animal soft tissue to be repaired or augmented; and (b) placing an injectable, liquid polyhydroxyalkanoate polymer or a polyhydroxyalkanoate microdispersion into the animal soft tissue, preferably using a minimally-invasive method such as injection. In another embodiment, the liquid polyhydroxyalkanoate polymer compositions or polyhydroxyalkanoate microdispersions are used as viscosupplements.

Degradable polylactic or polyhydroxyalkanoate polymers may be used to viscosify aqueous fluids for use in wells, Sand control screen or liner can be coated with a solid degradable polymer during placement in a well. Mechanical changes or flow changes in a well can be caused by solid degradable polymer that changes physical properties after it is placed in a well. Parts of devices or entire devices can be made of solid degradable polymer that converts to a fluid after selected times in an aqueous environment in a well.

Absorbable polyester fibers, braids, and surgical meshes with prolonged strength retention have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available, and could offer additional benefits such as anti-adhesion properties, reduced risks of infection or other post-operative problems resulting from absorption and eventual elimination of the device, and competitive cost. The devices may also be particularly suitable for use in pediatric populations where their absorption should not hinder growth, and provide in all patient populations wound healing with long-term mechanical stability. The devices may additionally be combined with autologous, allogenic and / or xenogenic tissues to provide implants with improved mechanical, biological and handling properties.

Coatings for an implantable medical device and a method of fabricating thereof are disclosed, the coatings including block-polymers comprising at least one poly(hydroxyacid) or poly(hydroxy-alkanoate) block, at least one block of a biologically compatible polymer and at least one type of linking moiety.

A polyurethane is described which is a reaction product of at least one isocyanate containing material having at least two isocyanate groups and at least one compound having at least two hydrogen atoms capable of reacting with the isocyanate. The compound having the at least two hydrogen atoms contains a hydroxyalkanoate, which is preferably a thermally decomposable or a biodegradable polyhydroxyalkanoate. The polyurethane of the present invention can be used in a number of applications and preferably has improved properties such as, but not limited to, improved flexibility and / or improved hydrophobicity. The polyurethanes of the present invention are preferably biodegradable and easily recycled.

Environmentally degradable molded or extruded articles comprising a blend of polyhydroxyalkanoate copolymer and an environmentally degradable thermoplastic polymer or copolymer are disclosed. Such compositions provide annealing cycle times to form molded or extruded articles that are less than annealing cycle times to form a molded or extruded article lacking the environmentally degradable thermoplastic polymer or copolymer.

An element of an absorbent article is provided. The element has a bio-based content of at least about 50% based on the total weight of the element, and comprises a synthetic polymer derived from a renewable resource via a first intermediate compound selected from the group consisting of crotonic acid, propiolactone, ethylene oxide, i-propanol, butanol, butyric acid, propionic acid, 2-acetoxypropanoic acid, methyl 2-acetoxypropanoate, methyl lactate, ethyl lactate, polyhydroxybutyrate, and a polyhydroxyalkanoate comprising 3-hydroxypropionate monomers. An absorbent article comprising the element and a method of making an element for an absorbent article also are provided.

A method for producing a polyhydroxyalkanoate with improved productivity and composition is provided. Polyhydroxyalkanoate is produced by a bacterium for producing polyhydroxyalkanoate in which a gene encoding acetyl-CoA acyltransferase is disrupted.

Absorbable polyester fibers, braids, and surgical meshes with improved handling properties have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available and have a decreased tendency to curl, in the preferred embodiment, due to the inclusion of relaxation and annealing steps following methods are characterized by the following physical properties: (i) elongation to break from about 17% to about 85% (ii) Young's modulus of less than 350,000 psi, (iii) knot to straight ratio (knot strength / tensile strength) of 55-80% or (iv) load at break from 1100 to 4200 grams.

The present invention provides polymers made by genetically engineering microorganisms for making a self-retaining suture. In an embodiment of the present invention the genetically engineering microorganisms synthesize polyhydroxyalkanoate (PHA) polymers. In an alternate embodiment of the invention, the genetically engineering microorganisms synthesize polybetahydroxybutyrate (PHB) polymers. In an alternative embodiment of the invention, the self-retaining sutures can be made from a copolymer such as polyhydroxybutyratevalerate (PHBV), where the genetically engineering microorganisms produces PHA polymers as the monofilament base material and a different genetically engineering microorganisms produces polyhydroxybutyratevalerate (PHBV) polymers. In various embodiments of the invention, recombinant expressed self-retaining suture materials have a melting point in the range from between approximately 40° C. to approximately 180° C. In various embodiments of the invention, recombinant expressed self-retaining suture materials have extension-to-break strength of between approximately 8% and approximately 42%.

Films comprising a blend of polyhydroxyalkanoate copolymer and destructured starch are disclosed. Laminates having a first layer comprising a PHA copolymer and a second layer comprising a PHA copolymer / starch blend or thermoplastic starch are also disclosed. Disposable articles comprising the environmentally degradable films or laminates are also disclosed.

The invention discloses slow-release fertilizer with the effect of soil remediation, which is prepared by polyhydroxyalkanoates which can be completely biodegraded, organic and inorganic nutrients and other substances, by slow-releasing the organic and inorganic nutrients, microorganism propagation and sustained and rapid growth of plants can be promoted, the bioactivity and water solubility of polycyclic aromatic hydrocarbons are quickened, and simultaneously, the defects of fertilizer loss and repeated fertilization can be avoided, thereby saving the cost and enhancing the soil remediation efficiency. The invention also discloses a soil pollution remediation method by utilizing the slow-release fertilizer, plants with the remediation effect are planted in the soil with the slow-release fertilizer, and efficient, environment-friendly and sustained remediation of the soil polluted by the polycyclic aromatic hydrocarbons (PAHs) can be realized by utilizing the microorganism-plant remediation technology.

Continuous processing methods for making absorbable polymeric non-wovens with one or more of the following properties: high burst strength, fine fibers of average diameter from 1 μm to 50 μm, and thickness from 10 μm to 50 mm, have been developed. Improved fiber cohesion is made possible by allowing the fibers of the non-woven to initially remain molten during web collection. In the preferred embodiment, the polymer is a polyhydroxyalkanoate, and in the most preferred embodiment, the polymer comprises 4-hydroxybutyrate. A particularly preferred embodiment is a non-woven of poly-4-hydroxybutyrate or copolymer thereof, wherein the non-woven has a burst strength greater than 0.1 Kgf, wherein the non-woven is derived by a continuous melt-blown process. The non-wovens can be used for a variety of purposes including fabrication of medical devices.

Interposition and augmentation devices for tendon and ligament repair, including rotator cuff repair, have been developed as well as methods for their delivery using arthroscopic methods. The devices are preferably derived from biocompatible polyhydroxyalkanoates, and preferably from copolymers or homopolymers of 4-hydroxybutyrate. The devices may be delivered arthroscopically, and offer additional benefits such as support for the surgical repair, high initial strength, prolonged strength retention in vivo, flexibility, anti-adhesion properties, improved biocompatibility, an ability to remodel in vivo to healthy tissue, minimal risk for disease transmission or to potentiate infection, options for fixation including sufficiently high strength to prevent suture pull out or other detachment of the implanted device, eventual absorption eliminating future risk of foreign body reactions or interference with subsequent procedures, competitive cost, and long-term mechanical stability. The devices are also particularly suitable for use in pediatric populations where their eventual absorption should not hinder growth.

Provided are processes for the production and high efficiency processing of polyhydroxyalkanoates (PHA) from carbon sources comprising carbon-containing gases or materials.

Recombinant hosts for producing polyhydroxyalkanoates and methods of producing polyhydroxyalkanoates from renewable carbon substrates are provided. Certain recombinant hosts that produce 5 carbon chemicals such as 5-aminopentanoate (5AP), 5-hydroxyvalerate (5HV), glutarate, and 1,5 pentanediol (PDO) are also provided. One embodiment provides a recombinant host expressing a gene encoding a heterologous enzyme selected from the group consisting of a polyhydroxyalkanoate synthase and a 5-hydroxyvalerate-CoA (5HV-CoA) transferase, wherein the host produces a polymer containing 5-hydroxyvalerate. Preferably, the host expresses both a polyhydroxyalkanoate synthase and a 5HV-CoA transferase. The host can be prokaryotic or eukaryotic. A preferred prokaryotic host is E. coli. The polymers produced by the recombinant hosts can be homopolymers or copolymers of 5-hydroxyvalerate. A preferred copolymer is poly(3-hydroxybutyrate-co-5-hydroxyvalerate).

The invention relates to a cell which has been genetically modified so as to be capable of producing more 2-hydroxyisobutyric acid or more polyhydroxyalkanoates containing 2-hydroxyisobutyric acid monomer units than its wild type, characterized in that 2-hydroxyisobutyric acid or polyhydroxyalkanoates containing 2-hydroxyisobutyric acid monomer units are produced via acetoacetyl-coenzyme A as intermediate and 3-hydroxybutyryl-coenzyme A as precursor.

A drug delivery system that includes micelles formed from an amphiphilic copolymer that includes an A polymer block comprising a poly(alkylene oxide) and a B polymer block comprising a poly(hydroxyalkanoate), and a therapeutically effective amount of at least one therapeutic agent intimately contained within the micelles. In one preferred embodiment of the invention, the A polymer block is poly(ethylene oxide) (PEO) and the B polymer block is poly[(R)-3-hydroxybutyrate] (PHB), and the copolymer is the triblock ABA copolymer PEO-PHB-PEO. A method of synthesizing the amphiphilic triblock copolymer is also provided.

A method for inexpensive and efficient PHA biosynthesis includes operating a sequencing bioreactor in alternating phases of nutrient deprivation and carbon feedstock deprivation to select for robust PHA-producing microbes. Preferably, the bioreactor is operated in a non-sterile manner with mixed cultures of methanotrophs. The method also preferably uses periodic biomass-wasting (PHA harvesting) at the end of the carbon feed phase, gradually lengthening the time period of carbon deprivation phase to create a penalty for rapid PHA degradation and incentive for PHA accumulation. Also, bacterial enrichment cultures may be introduced periodically. The PHA-accumulating bacteria are preferably grown on common anaerobic degradation products, specifically volatile fatty acids, such as acetate and propionate, and methane gas. The PHA has useful applications in bioplastics and other products.

The invention discloses a slow release fertilizer having a soil remediation function. The slow release fertilizer is prepared by mixing fully-biodegradable polyhydroxyalkanoates and organic and inorganic nutrient substances. The fully-biodegradable polyhydroxyalkanoates is slowly degraded under the actions of soil microorganisms to provide nutrient substances needed by the growth of the soil microorganisms so as to promote the ionization effects of the soil microorganisms on heavy metals and release the organic and inorganic nutrient substances by slow degradation so as to promote durable and rapid growth of plants and improve soil remediation efficiency. The invention also discloses a soil contamination remediation method for using the slow release fertilizer. High-efficiency, environmentally-friendly and durable remediation of heavy metal-contaminated soil is realized by planting plants having hyper-accumulation capability to absorb and extract the heavy metals in the soil to which the slow release fertilizer is applied.

The present invention provides a novel PHA comprising a unit containing thioether with high reactivity, and its production method. The present invention also provides polyhydroxyalkanoate (PHA) comprising units having defined chemical formulas (1) and (2), and at least one of four units having defined chemical formulas (3), (4), (5) and (6); its production method; a charge control agent containing the PHA; a toner binder containing the charge control agent; an electrostatic latent image developing toner; and an image forming method and an image forming apparatus using the electrostatic latent image developing toner.