2005 Volume 19 Pages 118-123
Biomimetic and functionally graded apatite (fg-HAp)ceramics were Prepard using bovine bone by the calcination and partial dissolution-precipitation methods.The fg-HAp ceramics had gradual distributions of the degree of crystallinity and the grain size of hydroxyapatite from the surface layer of the pore wall to the bulk structure region. The pore structure of the ceramics with specific surface areas of 30-40 m2·g-1 and porosities of 60-80 % was divided into a macro-pore originating from spongy bone and a micro-pore related to body fluid permeation and blood permeability.For implantation of the fg-HAp ceramics in subcutaneous tissue of rat, body fluid permeated the bulk region of the ceramics through the micro-pores. At 4 weeks after the implantation, a total size of the ceramics blocks remarkably decreased because of surface- and bulk-degradations of the fg-HAp. The body fluid was found to be immunopositive for an albumin, although in protein detection for the ceramics blocks by silver staining,several proteins with molecular weights of 20 to 70 kDa were recognized under non-reducing conditions.
