Cambridge Scientific, Inc.

Northeastern University

Depuy Mitek, Inc.

Dynatech Corporation

Joseph D Gresser

Donald L Wise

Debra J Trantolo

Robert Samuel Langer

Alexander M Klibanov

Kai-Uwe Lewandrowski

Don Churchill Augenstein

Yung-Yueh Hsu

Shrikar Bondre

Maurice V Cattaneo

Gary E Wnek

Herbert W Horne, Jr

Y Y Hsu

Abdul G Jimoh

Dean O Kuethe

A resorbable interbody fusion device for use in spinal fixation is disclosed. The device is composed of 25&#x2013;100% bioresorbable or resorbable material. The interbody fusion device of the invention can be in any convenient form, such as a wedge, screw or cage. Preferably, the resorbable device of the invention is in the shape of a tapered wedge or cone, which further desirably incorporates structural features such as serrations or threads better to anchor the device in the adjoining vertebrae. The preferred device further comprises a plurality of peripheral voids and more desirably a central void space therein, which may desirably be filled with a grafting material for facilitating bony development and/or spinal fusion, such as an autologous grafting material. As the preferred material from which the resorbable interbody fusion device is manufactured is most likely to be a polymer that can produce acidic products upon hydrolytic degradation, the device preferably further includes a neutralization compound, or buffer, in sufficiently high concentration to decrease the rate of pH change as the device degrades, in order to prevent sterile abscess formation caused by the accumulation of unbuffered acidic products in the area of the implant.

Resorbable interbody spinal fusion devices

A method by which immune responses to cortical bone grafts and other substrates (e.g., cement, IPN, etc.) can be minimized and at the same time graft osteoinductive potential can be improved, and improved graft substrate materials are disclosed. The method of the invention provides new types of bone grafts that incorporate into host bone more thoroughly and more rapidly, eliminating long-term complications, such as fracture, non-union, infection, and rejection. In the method of the invention, bone grafts or other substrates are modified to have an osteoinductive surface modification that the recipient's body will accept as its own tissue type and therefore will not reject or otherwise cause to fail. The osteoinductive surface modification comprises a biopolymer matrix coating that is seeded with periosteal cells that have been previously harvested either from the graft recipient or from an allogenic or xenogenic donor source.

Osteoinduction of cortical bone allografts by coating with biopolymers seeded with recipient periosteal bone cells

Tissue transplant coated with biocompatible biodegradable polymer

A resorbable interbody fusion device for use in spinal fixation is disclosed. The device is composed of 25-100% bioresorbable or resorbable material. The interbody fusion device of the invention can be in any convenient form, such as a wedge, screw or cage. Preferably, the resorbable device of the invention is in the shape of a tapered wedge or cone, which further desirably incorporates structural features such as serrations or threads better to anchor the device in the adjoining vertebrae. The preferred device further comprises a plurality of peripheral voids and more desirably a central void space therein, which may desirably be filled with a grafting material for facilitating bony development and/or spinal fusion, such as an autologous grafting material. As the preferred material from which the resorbable interbody fusion device is manufactured is most likely to be a polymer that can produce acidic products upon hydrolytic degradation, the device preferably further includes a neutralization compound, or buffer, in sufficiently high concentration to decrease the rate of pH change as the device degrades, in order to prevent sterile abscess formation caused by the accumulation of unbuffered acidic products in the area of the implant.

Method of making a biodegradable interbody spinal fusion devices

A bioerodible polymeric material, and in particular a semi-interpenetrating network (&ldquo;semi-IPN&rdquo;) alloy, is disclosed. A beneficial end use of this material is in the form of internal fixation devices (IFDs) (such as bone supports, plates, and pins) and as cured bone cements for bone repair. A multi-part bioerodible cement system, which, upon mixing of the system parts, forms a cured bioerodible cement, includes, in one part, a first bioerodible polymer (e.g., PLGA) capable of producing acidic products upon hydrolytic degradation, and, in another part, a second bioerodible scaffolding polymer (e.g., PPF) which upon crosslinking provides a biopolymeric scaffolding or internal reinforcement for the cured cement. In another aspect, a bone cement system of the invention includes a bioerodible scaffolding polymer (such as PPF), which when polymerized provides a hardened bone cement, the cement system further including a gas generating agent in stabilized form for providing the cured bone cement with pores for facilitating inward cell migration.

Bioerodible polymeric semi-interpenetrating network alloys for internal fixation devices and bone cements

An internal fixation device and a bioerodible implantable material useful therefor comprise a bioerodible polymer that produces acidic products or low molecular weight resorbable fragments upon hydrolytic degradation, and a buffering or neutralizing agent in sufficiently high concentration to moderate the rate of change of pH of said bioerodible material during bioerosion. The buffering or neutralizing agent acts to reduce the inflammatory foreign body response generated by the acidic products and reduces the sterile abscess condition that occurs at the site of the bioerodible implant materials of the prior art. Internal fixation devices (IFDs) according to the invention are useful, for example, for the repair, replacement or reconstruction of damaged bone in any area of the body.

Buffered resorbable internal fixation devices and methods for making material therefore

A bioerodible cement system, which, upon mixing of the system parts, forms a cured bioerodible cement, said system comprising a first part comprising a first bioerodible polymer capable of producing acidic products upon hydrolytic degradation; and a second part comprising a second bioerodible scaffolding polymer which upon crosslinking provides a biopolymeric scaffolding or internal reinforcement for said cured cement is disclosed. In a preferred embodiment, the second bioerodible polymer comprises polypropylene fumarate (PPF), which is cross-linked during curing, desirably by a vinyl monomer such as vinyl pyrrolidone (VP) to form the biopolymeric scaffolding which provides the cured cement with dimensional and geometric stability.

Bioerodible polymeric semi-interpenetrating network alloys and internal

A bioerodible polymeric semi-IPN alloy which comprises a first bioerodible polymer capable of producing acidic products upon hydrolytic degradation; a second bioerodible polymer, which provides a biopolymeric scaffolding or internal reinforcement; and optionally a buffering compound that buffers the acidic products within a desired pH range. In a preferred embodiment, the second bioerodible polymer comprises polypropylene fumarate (PPF), which is cross-linked, desirably by a vinyl monomer such as vinyl pyrrolidone (VP) to form the biopolymeric scaffolding which provides the semi-IPN with dimensional and geometric stability.

Bioerodible polymeric semi-interpenetrating network alloys for surgical

A bioerodible implantable material, comprising a bioerodible polymer that produces acidic products upon hydrolytic degradation, and a buffering compound that buffers the acidic products and maintains the local pH within a desired range. The buffer compound acts to reduce the inflammatory foreign body response generated by the acidic products and reduces the sterile abscess condition that occurs at the site of the bioerodible implant materials of the prior art. Materials made according to the invention may be used for internal fixation devices (IFDs) for bone repair.

Material for buffered resorbable internal fixation devices and method

A biopolymer film and other materials that exhibit nonlinear optical (NLO) properties and a method for making this film. Alignment of biopolymer molecules, which is required for NLO phenomena, is achieved by application of an electric field parallel to the surface of a biopolymer solution as the film is formed. In one embodiment, a solution of poly(.gamma.-benzyl-L-glutamate), PBLG, in methylene chloride is employed. Upon application of an electric field, laminar structures perpendicular to both the field direction and to the film surface are formed. These ordered structures are captured in the film upon evaporation of the biopolymer solvent.

Method of making biopolymer-based nonlinear optical materials

A method for making an implantable bioerodible material for the sustained release of a medicament and the material made from the method. The method comprises the formulation of a biomaterial polymeric carrier into particles of predetermined density and size. The particles are then are mixed with the desired medicament and extruded into the desired shape for implantation or reground to a predetermined size distribution for injection as a suspension. In an alternative embodiment, the particles of polymeric carrier are immersed in a solvent containing a medicament, and the pores of the particles are filled with medicament through alternate application and release of vacuum.

Method for making a bioerodible material for the sustained release of a

A biodegradable polymeric multiphasic release system of one or more biodegradable bursting units capable of delivering biologically active substances in a burst or pulse at predetermined times and a method for constructing those units is disclosed. The individual bursting units of the system may take the form of a biodegradable, membrane coated capsule surrounding a core material which may include an active agent. The membrane ruptures after a predetermined time upon exposure to water or bodily, or other aqueous environmental fluids. The bursting units may be used in any situation in which a controlled pulsed release of an active substance is desired. The predetermined time release of each bursting unit is controlled by the composition of the core material, the initial radius and wall thickness of the membrane and the porosity of the membrane. The core material may also contain a chemical composition which generates gas as fluid is drawn into the bursting unit thus adding an additional design variable for predetermining bursts.

Biodegradable bursting release system

A process for the manufacture of alkaline earth salts of acetic acid. Biomass is fermented under appropriate conditions to produce acetic acid, which is extracted from the fermentation broth with the aid of a basic liquid ion exchanger dissolved in an organic phase. The organic phase containing the product acetic acid is then reacted directly with a basic material such as limestone, and the resulting alkaline earth acetate product is recovered from the aqueous phase.

Process for manufacture of alkaline earth acetates

A two-stage device for use within the canal of the cervix of the uterus for the dual and simultaneous purposes of venereal disease prevention and of contraception by prohibiting the migration of sperm through the cervical canal. The two-stage device will consist of (Part A) an insertable member which will be inserted into and be maintained within the cervical canal to which (Part B) a temporary member, effective for upward of a year, can be attached easily with a minimum of discomfort to the patient. [Either or both parts of this two-stage device (at present most probably the temporary part) can incorporate metals such as copper, silver, or others, or suitable compounds thereof, and also spermicidal and pathogenocidal agents, steroids or other drugs.] A unique feature of the invention is its placement within the cervical canal rather than in the fundus or vagina. Part A of the device is designed for semipermanent placement within the cervical canal; its main structural function is to act as a support for Part B which is designed for facile and comfortable removal and replacement and which contains the active agents possibly but not necessarily contained within a slow release matrix. A second unique feature of the invention is the use of magnets to attach Part B to Part A.

Growing community of inventors

Brookline, MA, United States of America

Joseph D Gresser