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Biodegradation and bioabsorption innovation of the functionally graded bovine bone–originated apatite with blood permeability
Author(s) -
Akazawa Toshiyuki,
Murata Masaru,
Sasaki Tomoya,
Tazaki Junichi,
Kobayashi Masayoshi,
Kanno Tohru,
Nakamura Katsuo,
Arisue Makoto
Publication year - 2006
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.30439
Subject(s) - simulated body fluid , materials science , crystallinity , calcination , apatite , ceramic , bone tissue , bovine serum albumin , dissolution , chemical engineering , mineralogy , composite material , biomedical engineering , chromatography , chemistry , scanning electron microscope , medicine , biochemistry , engineering , catalysis
Bioabsorbable and functionally graded apatite (fg‐HAp) ceramics were designed using bovine bone by the calcination and partial dissolution–precipitation methods. The fg‐HAp ceramics that were developed had gradual distributions of the degree of crystallinity and the grain size of single‐phase hydroxyapatite from the surface layer of the pore wall to the bulk structure region. Calcination at 1073K gave a specific surface area of 30 m 2 · g −1 and porosities of 60–80%. The pore structure of the fg‐HAp was classified into two regions: a macro‐pore region (100–600 μm) originating from spongy bone and a micro‐pore region (10–160 nm) related to body fluid permeation and blood permeability. By implantation in subcutaneous tissue of rat, it was confirmed that body fluid permeated the bulk region of the fg‐HAp ceramics through the micro‐pores. The volumetric populations occupied by body fluid were 60% at 4 weeks and 68% at 8 weeks in the ceramics explants, indicating drastic bioabsorption, although the body fluid was found to be immunopositive for an albumin as the main serum protein in blood. On the fg‐HAp ceramics developed here, the bioabsorption rate could be controlled by careful selection of the calcination temperature. These ceramics can be applied as new biomimetic ceramics exhibiting surface and bulk degradations and cellular absorption by giant cells. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006