Hercules Corporation

General Electric Company

Gore Enterprise Holdings, Inc.

Samuel A Thompson, Iii

Fred W Kelley, Jr

Andrew B Woodside

Richard Lee Brady

Brian J Swetlin

Anita N Chan

Gary A Luzio

Chester R Willis

The present invention provides shaped medical devices adapted for implant and subsequent in-vivo disintegration within a human or animal body. In one embodiment, the medical device is fabricated from a matrix polymer component, e.g., a lactam, which has a ceiling temperature (Tc) within the range of from about 40.degree. C. to about 76.degree. C. Decomposition of this device is accomplished by heating the device in-vivo to a temperature at or above the ceiling temperature of the matrix polymer component. In another embodiment, the medical device is fabricated from an end-capped polyoxyalkylene matrix polymer component characterized by a depolymerization temperature of at least about 40.degree. C. and a ceiling temperature of 76.degree. C. or less after removal of the end-cap group. In a third embodiment of the invention the medical device comprises a matrix polymer which is insoluble or only slightly soluble in normal body fluids and which exhibits a Tc below 40.degree. C. This device is stored and handled at T&lt;Tc such that depolymerization and disintegration of the device does not begin until the device is implanted.

Medical devices composed of low ceiling temperature polymers

This invention provides a method of altering the water content of a hydrogel comprising treatment of said hydrogel with a liquid dehydrating composition. There is further provided a method of altering the water content of a hydrogel-containing medical device. The medical devices of the present invention comprise a hydrogel having a water level ex vivo lower than the thermodynamic equilibrium water level when in vivo. These medical devices comprise a hydrogel contacted with a liquid dehydrating agent, wherein said medical device has a lower water level ex vivo than the thermodynamic equilibrium water level when the medical device is in vivo.

Crosslinked hydrogel compositions with improved mechanical performance

The invention discloses temporary medical devices such as stent implants which can be disintegrated in-vivo upon demand by release of an agent held trapped within the device. The device is fabricated from a matrix polymer material which is essentially insoluble in body fluids and a disintegration agent which acts to initiate decomposition of the matrix polymer when contacted therewith. The disintegration agent is trapped within and chemically isolated from the matrix polymer such as by encapsulation, and is releasable within the matrix polymer upon contact of the device with a releasing agent which liberates the encapsulated disintegration agent.

Medical devices containing triggerable disintegration agents

The present invention provides medical devices comprised of ionically crosslinked polymer, especially, stents, catheter or cannula components, plugs, and constrictors. The medical devices of the present invention are prepared by treatment of ionically crosslinkable polymer compositions with crosslinking ion compositions to provide ionically crosslinked materials. An important aspect of the present invention is that these medical devices can be disintegrated in-vivo at a desired time through the exposure of the medical device to a chemical trigger which generally is described as an agent that acts to displace the crosslinking ion in the ionically crosslinked material through binding or simple replacement with a non-crosslinking ion.

Medical devices subject to triggered disintegration

A reactive component, which is curable to form a nonpolar polymer containing silicon and carbon atoms, and having a glass transition temperature of at least 20.degree. C., is mixed with an antiplasticizer. The resulting mixture, a curable composition, is cured to form a composition having an increased modulus. The reactive component preferably comprises a polyene having at least two hydrosilation reactive carbon-carbon double bonds (e.g., dicyclopentadiene), and a silicon compound having at least two hydrosilation reactive .ident.SiH groups. Preferably the silicon compound comprising at least one member selected from the group consisting of cyclic polysiloxanes, tetrahedral siloxysilanes, and linear polysiloxanes. Preferably the resulting cured composition is crosslinked, due to at least one member selected from the group consisting of the polyene and the silicon compound having more than two hydrosilation reactive sites. Preferably the curable composition further comprises a hydrosilation catalyst.

Nonpolar polymers comprising antiplasticizers

Epoxy resin compositions having improved storage stability before curing and improved thermal and mechanical performance after curing comprise a mixture of a polyepoxide and a curing agent that is reactive with the polyepoxide. The epoxy resin composition is characterized by a glass transition temperature of less than 20.degree. C., measured under standard conditions, after subjecting the epoxy resin composition to a specified thermal cycle. The preferred curing agents are aromatic diamines, for example, 3,7-diaminodibenzothiophene-5,5-dioxide; 3,7-diaminophenothiazine sulfone, 3,7-diamino-N-methylphenothiazine sulfone; 2,7-diamino-9-fluorenone and 2,4,6,8-tetramethyl-3,7-diaminothioxanthene sulfone.

Epoxy resin compositions with improved storage stability

A dc measuring circuit for power rectifiers is described wherein primary line current is utilized to measure direct current output. In the measuring circuit, line current transformers are connected to a multiphase instrument rectifier through a phase shifting current transformer which is adjustable to compensate for differences between the primary and secondary line current phase shift characteristics of the power transformer and any phase shift in the line current transformer. By such compensation, the average value of rectified primary line current in the measuring circuit is maintained independent of the commutating angle of the rectified power current. The dc measuring circuit includes means for providing unity current transformation through the phase shifting current transformer. The dc measuring circuit also includes means for handling the presence of zero sequence current without causing measurement error or circuit damage. The dc measuring circuit also includes means for indicating the blowing of a fuse associated with the power rectifier circuit. In one embodiment, the phase shifting current transformer comprises a double extended wye connected autotransformer. In another embodiment, the phase shifting current transformer comprises a truncated delta autotransformer.

Growing community of inventors

Wilmington, DE, United States of America

Samuel A Thompson, Iii