| 摘要 |
The invention relates to an inorganic resorbable bone substitute material based on calcium phosphates and to a method for producing the same. The material is characterized in that it comprises a loose crystal structure, i.e. the crystallites are not tightly connected as in a solid body (ceramic), but they are interconnected via only a few molecular groups. The volume which is occupied by collagen in natural bone is provided in the material as interconnecting pores in the nanometer range. A second pore size, also interconnecting and in the range of a few micrometers, permits collagen fibers to grow inside during tissue formation. These fibers are nucleators for the inserting biomineralization (formation of the endogenous biological apatite). The material contains a third interconnecting pore category which is modeled on the spongiosa and thus ranges from approximately 100 mu m to 1000 mu m while enabling a vascularization of blood vessels such that the resorption and the bone regeneration not only occurs as the surface of healthy bone but also takes place throughout the entire defect. The high inner surface of the material permits the bonding of endogenous or synthetic growth factors. The invention also relates to a method for producing such a material which is characterized in that a highly viscous suspension of a sol of one or more oxides of the elements X (X = Al, Ca, Mg, P, Si, Ti, Zr) that is mixed with a crystalline powder is forced through a nozzle or a nozzle system and subsequently formed into any desired shape so that an open porous structure with a size corresponding to that of the filament diameters results by packing the fibers from the highly viscous suspension whose viscosity prevents the material from dispersing.
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