Malleable implants containing demineralized bone matrix

#The present invention relates generally to medical implants. In more particular aspects, the present invention relates to osteoinductive implant formulations containing demineralized bone matrix.

#A wide variety of implant formulations have been suggested in the art for the treatment of bone defects. In addition to traditional bone grafting, a number of synthetic bone graft substitutes have been used or explored, including some materials that contain demineralized bone matrix. Demineralized bone matrix has been shown to exhibit the ability to induce and/or conduct the formation of bone. It is thus desirable to implant and maintain demineralized bone matrix at a site at which bone growth is desired.

#However, the beneficial nature of demineralized bone matrix is susceptible to disruption by the incorporation of incompatible materials or techniques when formulating the medical implant material. At the same time, effective implant compositions must exhibit properties that retain the demineralized bone matrix at the implant site, and that handle well in the operating environment. As well, it is of considerable commercial significance that the formulation be manufacturable without undue cost, equipment or material burdens.

#FIG. 1 provides a perspective view of a medical product of the invention including a medical paste or putty of the invention packaged within a terminally sterilized syringe device.

#FIG. 2 provides a perspective view of a dry disruptable body that can be used to prepare malleable implant compositions of the invention.

#For the purposes of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as described herein being contemplated as would normally occur to one skilled in the art to which the invention relates.

#As disclosed above, in certain aspects, the present invention relates to implantable medical formulations, and to methods for making and using the formulations. In particular embodiments, the present invention provides medical formulations that include a malleable composition comprised of solids and a liquid carrier, such as paste or putty formulations. The solids include a substantial level of demineralized bone matrix particles. In particularly advantageous embodiments, the demineralized bone matrix particles will be effective to render the formulation osteoinductive when implanted in a mammalian patient, including a human patient. The liquid carrier advantageously includes an aqueous medium containing a polysaccharide, and especially a water soluble alginate. Further, certain advantageous medical formulations include particulate collagen, such as collagen fibers or randomly fragmented collagen sponge, in an amount that is relatively less than the amount of particulate DBM on a dry weight basis. The inventive formulations desirably retain the DBM in a bioactive, osteoinductive condition, while also providing beneficial handling and implant properties.

#Malleable implant formulations of the invention will include an amount of insoluble solids combined with the liquid carrier material. The solids include a particulate-form demineralized bone matrix material. In this regard, as used herein, the term “demineralized bone matrix” refers to a matrix material prepared by demineralizing any bone source, including cortical and/or cancellous bone. Desirable demineralized bone matrix materials will contain less than about 5% by weight of residual calcium. The source bone can be from any suitable source including autogenic, allogenic, and/or xenogenic bone. When used in describing a demineralized bone matrix (DBM) material, the term “osteoinductive” refers to the ability of the DBM material to induce bone growth. Alternatively, DBM materials can be provided lacking osteoinductive character, and nonetheless be used as osteoconductive materials that provide a scaffold capable of receiving bone growth induced by natural healing processes or other materials implanted in the patient.