Plasticized bone and soft tissue grafts and methods of making and using same

Abstract

The present invention provides a plasticized dehydrated or freeze-dried bone and/or soft tissue product that does not require special conditions of storage, for example refrigeration or freezing, exhibits materials properties that approximate those properties present in normal hydrated tissue, is not brittle, does not necessitate rehydration prior to clinical implantation and is not a potential source for disease transmission. The invention replaces water in the molecular structure of the bone or soft tissue matrix with one or more plasticizers allowing for dehydration of the tissue, yet not resulting in an increase in brittleness of the plasticized product, and resulting in compressive and/or tensile properties similar to those of normal hydrated bone. Replacement of the chemical plasticizers by water prior to implantation is not required and thus, the dehydrated bone or soft tissue plasticized product can be placed directly into an implant site without significant preparation in the operating room.

Description

[0001] This is a continuation application of U.S. patent application Ser. No. 09 / 940,545, filed on Aug. 29, 2001, now U.S. Pat. No. ______, which is a divisional application of U.S. patent application Ser. No. 09 / 107,459 filed on Jun. 30, 1998, now U.S. Pat. No. 6,293,970.FIELD OF THE INVENTION [0002] The present invention provides a plasticized dehydrated bone and / or soft tissue product that does not require special conditions of storage, for example refrigeration or freezing, exhibits materials properties that approximate those properties present in normal hydrated tissue, is not brittle and does not necessitate rehydration prior to clinical implantation. The invention replaces water in the molecular structure of the bone or soft tissue matrix with one or more plasticizers allowing for dehydration of the tissue, yet not resulting in an increase in brittleness of the plasticized product, and resulting in compressive and / or tensile properties similar to those of normal hydrated bone...

AI Technical Summary

Benefits of technology

[0018] It is yet a further objective of the present invention to provide bone and soft tissue products which can be stored at room temperature using conventional packaging.

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Problems solved by technology

Tightly bound water can be removed only under extreme conditions and results in significant changes in the physical and mechanical properties of bone tissue.

Fractures as discussed above can occur in dehydrated bone prior to rehydration and result in a graft having compromised biomechanical properties, which in turn can result in graft failure when implanted in a patient.

Bone and soft tissue products preserved and stored by methods involving freeze-drying (removal of water by sublimation) yield a bone or soft tissue product which is significantly more brittle than normal bone and has a tendency to fracture into numerous small pieces, which ultimately can result in graft failure.

Specifically, freeze-drying causes grafts to be brittle and typically causes shrinkage where the shrinkage is often not uniform, thereby causing graft failure; solvent preservation using f