Abstract:
A medical device includes a balloon catheter having an expandable member, e.g., an inflatable balloon, at its distal end and a stent or other endoprosthesis. The stent is, for example, an apertured tubular member formed of a polymer and is assembled about the balloon. The stent has an initial diameter for delivery into the body and can be expanded to a larger diameter by inflating the balloon.
Abstract:
Described are conjugated polymer fibers and nanofibers, methods of making, and methods of use thereof. The conjugated polymer fibers and nanofibers can be prepared by an electrostatic spinning process followed by crosslinking.
Abstract:
A medical device includes a balloon catheter having an expandable member, e.g., an inflatable balloon, at its distal end and a stent or other endoprosthesis. The stent is, for example, an apertured tubular member formed of a polymer and is assembled about the balloon. The stent has an initial diameter for delivery into the body and can be expanded to a larger diameter by inflating the balloon.
Abstract:
A shape memory composite consisting of an electrospun non-woven fiber mat and an elastomeric resin matrix. The fiber mat is made from a semi-crystalline polymer, poly(ε-caprolactone) (PCL) and serves as the “switching phase” for shape fixing and recovery. The resin matrix, a crosslinked PDMS elastomer, imparts softness as well as entropic elasticity to the material. PCL is first electrospun from a chloroform/DMF solution. The resulting microfiber mat was then immersed in a two-part (base resin and crosslinking agent) mixture of Sylgard 184 with a vacuum applied to infiltrate the fiber mat with the mixture. The infiltrated fiber mat is then removed from the mixture and cured at room temperature for two days.
Abstract:
Shape memory main-chain smectic-C elastomers are described, as are methods for their preparation and monomers used in such methods. The elastomers are prepared by hydrosilylation of a reaction mixture including a liquid crystalline diene, a crosslinking agent, and a bis(silyl hydride) compound. The elastomers exhibit shape-memory properties and spontaneously reversible shape changes. They are useful for fabrication of shape memory articles including, for example, implantable medical devices, contact lenses, reversible embossing media, and Fresnel lenses.
Abstract:
Chemically crosslinked polycyclooctene having excellent shape recovery properties is prepared by ring-opening metathesis polymerization of cis-cyclooctene followed by chemical crosslinking. The crosslinked polycyclooctene can be shaped, the shape memorized, a new shape imparted with the original shape being recoverable by suitable temperature adjustment. The dependence of shape memory characteristics on degree of crosslinking was established. In addition to polycyclooctene, blends thereof with other materials such as SBR, EVA, polyurethane rubbers, and inorganic fillers can be utilized to provide chemically crosslinked products having excellent and tailored shape memory properties.
Abstract:
Shape memory main-chain smectic-C elastomers are described, as are methods for their preparation and monomers used in such methods. The elastomers are prepared by hydrosilylation of a reaction mixture including a liquid crystalline diene, a crosslinking agent, and a bis(silyl hydride) compound. The elastomers exhibit shape-memory properties and spontaneously reversible shape changes. They are useful for fabrication of shape memory articles including, for example, implantable medical devices, contact lenses, reversible embossing media, and Fresnel lenses.
Abstract:
Described are compositions that include a crosslinked polymer obtained on crosslinking a particular class of uncrosslinked polymers having in-chain aliphatic double bonds. The compositions exhibit unusual shape memory properties, and they may be used to form objects that exhibit at least three different shapes as a function of temperature.
Abstract:
Blends of amorphous and semicrystalline polymers having shape memory properties were prepared by blending a crystalline polymer such as poly(vinylidene fluoride), polylactide, poly(hydroxxybutyrate), poly(ethylene glycol) polyethylene, polyethylene-co-vinyl acetate, poly(vinyl chloride), poly(vinylidene chloride) and copolymers of poly(vinylidene chloride) and poly(vinyle chloride) and an amorphous polymer such as poly(vinyl acetate), poly methyl acrylate, poly ethyl acrylate, atactic poly methyl methacrylate, isotactic poly methyl methacrylate, syndiotactic poly methyl methacrylate and other poly alkyl methacrylates. The method for preparing the polymeric materials and applications thereof, for example, as smart medical devices, are also disclosed.