摘要:
This invention describes a partially absorbable, fiber-reinforced composite in the form of a ring, or a suture-like thread, with modified terminals for use as a controlled delivery system of at least one bioactive agent, wherein said composite comprising an absorbable fiber construct capable of providing time-dependent mechanical properties of a biostable elastomeric matrix containing an absorbable microparticulate ion-exchanger to modulate the release of the bioactive agent(s) for a desired period(s) of time at a specific biological site; this can be a vaginal canal, peritoneal cavity, scrotum, prostate gland, an ear loop or subcutaneous tissue. Such drug delivery systems can be used for the local administration of at least one bioactive agent, including those used as contraceptive, antimicrobial, anti-inflammatory and/or antiviral agents as well as for cancer treatment.
摘要:
Self-setting, bioactive, absorbable composites are derived from inorganic phosphate microparticles and a cyanoacrylate matrix of a methoxypropyl cyanoacrylate at a weight to volume ratio of at least 20/80 of microparticles/matrix. The self-setting composites are capable of the controlled release of bone mineralizing ions, antimicrobials, and bone growth promoters. Such composites are useful as bone cements, fillers, and/or substitutes.
摘要:
The present invention is directed to crystalline copolymers of l-lactide and a minor portion of a cyclic monomer, preferably ε-caprolactone or trimethylene carbonate or both. The present copolymers have a melting temperature of at least 150° C. and a crystallinity of at least 20%. Preferred are high molecular weight copolymers having an inherent viscosity of at least 1.1 dl/g. A variety of surgical constructs may be formed from the present copolymers. Surgical sutures made of mono- or multifilament yams of the present copolymers will bioabsorb in less than three years and will maintain at least 50% of their initial strength three weeks post-operatively.
摘要:
The present invention is directed to adhesive/hemostatic formulations of 2-alkoxyalkyl cyanoacrylate, an absorbable liquid or solid polymeric modifier, and a general stabilizer against premature anionic polymerization of cyanoacrylates. The present adhesive formulations are useful as tissue adhesives/sealants, hemostatic agents, or as a means of patching and anastomotic coupling of damaged organs.
摘要:
A method for modifying a protein or polypeptide is disclosed which includes the steps of dispersing a protein or polypeptide in an essentially non-aqueous medium and peracylating the protein or polypeptide with a cyclic anhydride having a carbon chain substituent selected from the group consisting of alkyl and alkenyl groups. Most preferably, the cyclic anhydride is succinic anhydride, although glutaric anhydride may also be employed. Preferably, the step of peracylating the protein or polypeptide is performed in the presence of an acid catalyst, most preferably .rho.-toluene sulfonic acid. The resultant modified protein or polypeptide may be employed in numerous applications including drug delivery, absorbable sutures, and thermoplastic films and molded articles.
摘要:
Disclosed are fiber-reinforced composites having untraditionally low fiber loading and a novel form of hybridized interface. Typical examples of fiber-matrix combinations capable of developing such interfaces include surface-phosphonylated ultrahigh molecular weight polyethylene (UHMW-PE) and polypropylene (PP) yarns (or fabric constructs) and epoxy resin, acrylic resin, and cement. For further improvement of the hybridized interface and the overall composite properties, the surface-phosphonylated fiber may be post-treated with reagents that will improve the abridging of the fibers to the matrix through physicochemically hybridized interfaces. Compared with composites having unmodified fiber, those based on modified ones, with or without post-treatment, exhibit a substantial increase in physicomechanical properties at exceptionally low fiber loading, ranging from about 0.1 to 35 percent by weight, preferably from about 0.1 to about 20 percent by weight, most preferably less than 10 percent by weight. Among these properties are maximum tensile strength, fracture toughness, and modulus.
摘要:
The invention provides composites of ultra-high molecular weight polyethylene reinforced with ultra-high molecular weight polyethylene anisotropic reinforcement of high strength and modulus. The composites have superior mechanical properties relative to non-filled ultra-high molecular weight polyethylene, including higher strength, impact strength, increased creep resistance, and improved modulus. The composites may be sterilized for biomedical use, using gamma radiation and other techniques. Further, the composites are resistant to the effect of body fluids and have lower creep rates so that they will provide implant life. The composites may be cross-linked by exposure to an acetylene environment. Also, the composites find use in other high strength, high impact applications such as sports equipment.
摘要:
Polymers and formulated compositions are designed to have properties that allow their effective use in additive manufacturing processes, particularly for preparing articles wherein molten monofilament polymer is laid down on top of a previously deposited line of molten monofilament polymer.
摘要:
A radiation and radiochemically sterilized, multi-component, fiber-reinforced composite, absorbable/disintegratable urinogenital stent, such as an endoureteral stent, with radiomodulated residence time in the biological site of 1 to 10 weeks depending on the high energy radiation dose used for sterilization.
摘要:
A fabric or mesh construct, and process for making same, which allows for early wound stability and then transitions to a more compliant state exhibiting a substantially constant macro-porous pore structure through the life of the implant to promote good tissue incorporation without bridging.