Edwards Lifesciences Corporation

Baxter International Inc.

Other

Jeffrey S Dove

Gregory A Wright

James A Davidson

Darin P Dobler

Louis A Campbell

Ralph Schneider

John F Migliazza

Bin Tian

Ivan Jankovic

James M Young

Jeffrey S Cohen

Dengfeng Xu

Amy E Munnelly

Tara J Tod

Minsey Lee

Jeff Cohen

Harold Alexander Heitzmann

Lauralan T Grisoni

Jim A Davidson

Darin Dobler

Tara Tod

Methods are provided herein for modifying antigenic carbohydrate epitopes within a xenographic bioprosthetic tissue by oxidation of vicinal diols to form aldehydes or acids and subsequence reductive amination of aldehydes to form stable secondary amines, or amidation or esterification of acids to form stable amides or esters. Advantageously, methods provided herein mitigate the antigenicity of the bioprosthetic tissue while leaving the overall tissue structure substantially undisturbed, and thereby enhance the durability, safety and performance of the bioprosthetic implant.

Methods for stabilizing a bioprosthetic tissue by chemical modification of antigenic carbohydrates

Methods for treating a bioprosthetic tissue are described herein. The methods comprise contacting the bioprosthetic tissue with at least one nucleophile and/or at least one electrophile in the presence of a catalytic system comprising at least one or a combination of a fluoride-based salt, a cesium-based salt, a potassium-based salt, a rubidium-based salt, or a carbonate-based salt. The methods may be used to alter functional groups on biological tissue which represent actual and potential calcium binding sites and also processes for cross-linking bioprosthetic tissue. Both processes may be used in conjunction with known fixative techniques, such as glutaraldehyde fixation, or may be used to replace known fixative techniques.

Methods for treating bioprosthetic tissue using a nucleophile/electrophile in a catalytic system

A bioprosthetic tissue having a reduced propensity to calcify in vivo, the bioprosthetic tissue. The bioprosthetic tissue comprises an aldehyde cross-linked and stressed bioprosthetic tissue comprising exposed calcium, phosphate or immunogenic binding sites that have been reacted with a calcification mitigant. The bioprosthetic tissue has a reduced propensity to calcify in vivo as compared to aldehyde cross-linked bioprosthetic tissue that has not been stressed and reacted with the calcification mitigant.

Bioprosthetic tissue having a reduced propensity for in vivo calcification

Methods for the conditioning of bioprosthetic material employ bovine pericardial membrane. A laser directed at the fibrous surface of the membrane and moved relative thereto reduces the thickness of the membrane to a specific uniform thickness and smoothes the surface. The wavelength, power and pulse rate of the laser are selected which will smooth the fibrous surface as well as ablate the surface to the appropriate thickness. Alternatively, a dermatome is used to remove a layer of material from the fibrous surface of the membrane. Thinning may also employ compression. Stepwise compression with cross-linking to stabilize the membrane is used to avoid damaging the membrane through inelastic compression. Rather, the membrane is bound in the elastic compressed state through addition cross-linking. The foregoing several thinning techniques may be employed together to achieve strong thin membranes.

Methods of conditioning sheet bioprosthetic tissue

A method for manufacturing a heart valve using bioprosthetic tissue that exhibits reduced in vivo calcification. The method includes applying a calcification mitigant such as a capping agent or an antioxidant to the tissue to specifically inhibit oxidation in tissue. Also, the method can be used to inhibit oxidation in dehydrated tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the oxidation and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. In one method, tissue leaflets in assembled bioprosthetic heart valves are pretreated with an aldehyde capping agent prior to dehydration and sterilization.

Heart valve with reduced calcification

A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification is disclosed. The method includes preconditioning, pre-stressing, or pre-damaging fixed bioprosthetic tissue in a manner that mimics the damage associated with post-implant use, while, and/or subsequently applying a calcification mitigant such as a capping agent or a linking agent to the damaged tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the damage process (service stress) and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. The linking agent will act as an elastic reinforcement or shock-absorbing spring element in the tissue structure at the site of damage from the pre-stressing. In one method, tissue leaflets in assembled bioprosthetic heart valves are preconditioned by simulating actual flow conditions for a predetermined number of cycles, during or after which the valve is exposed to the capping agent.

Pre-stressing and capping bioprosthetic tissue

An assembly and methods for providing a contoured biological tissue are described. The assembly comprises a first plate and a second plate. The first plate is configured to receive a biological tissue. The second plate is configured to contact and compress the biological tissue received on the first plate. One or both of the first and second plates comprise a defined shape and a contoured area within the defined shape. The contoured area comprises at least first and second elevations. One or more energy sources are associated with one or both of the first and second plates. The one or more energy sources deliver energy upon compression of the biological tissue.

Method and apparatus for preparing a contoured biological tissue

A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification. The method includes applying a calcification mitigant such as a capping agent or an antioxidant to the tissue to specifically inhibit oxidation in tissue. Also, the method can be used to inhibit oxidation in dehydrated tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the oxidation and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. In one method, tissue leaflets in assembled bioprosthetic heart valves are pretreated with an aldehyde capping agent prior to dehydration and sterilization.

Bioprosthetic tissue with reduced calcification

An assembly and methods for providing a contoured biological tissue are described. The assembly comprises a first plate and a second plate. The first plate is configured to receive a biological tissue. The second plate is configured to apply a compressive force on the biological tissue that is disposed on the first plate. One or both of the first and second plates comprise a defined shape and a contoured area within the defined shape. The contoured area comprises at least first and second elevations and a continuous transition between the first and second transitions. One or more energy sources is associated with one or both of the first and second plates. The one or more energy sources delivers energy while the second plate applies the compressive force on the biological tissue disposed on the first plate.

Growing community of inventors

Santa Ana, CA, United States of America

Jeffrey S Dove