Chem. Mater. 2002, 14, 3326-3331

 

Periodic Macroporous Hydroxyapatite-containing Calcium Phosphates

 

Brian J. Melde and Andreas Stein*

 

Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455

 

Abstract

 

Three-dimensionally ordered macroporous materials containing the bioceramic hydroxyapatite as well as other calcium phosphate and carbonate phases have been synthesized using close-packed poly(methyl methacrylate) latex spheres (256-375 nm diameter) as templates. The interstitial spaces of the colloidal crystal were penetrated by a water-alcohol co-solvent solution of calcium nitrate and phosphoric acid. Calcination in the range 475-1000 °C removed the polymer and promoted crystallization of calcium phosphate phases in the pore walls. Materials were characterized by powder X-ray diffraction, FT-IR, and SEM. The best combination of composition and three-dimensional order was found in a crystalline hydroxyapatite/tricalcium phosphate templated with 375 nm size spheres and calcined at 700 °C. An in vitro antibiotic drug release application was tested using this product.