Growth-inhibited hydroxyapatite, process for its preparation and use

Abstract

A growth-inhibited hydroxyapatite is contained in agglomerates of prestructured collagen templates, wherein the prestructured collagen templates are denatured or broken up so that fibrillogenesis of the prestructured collagen templates is inhibited. Epitactic hydroxyapatite crystallites with a crystallite size below a critical nucleus radius are formed on the prestructured collagen templates.

What is claimed is: 
     
         1 . A growth-inhibited hydroxyapatite contained in agglomerates of prestructured collagen templates, wherein the prestructured collagen templates are denatured or broken up so that fibrillogenesis of the prestructured collagen templates is inhibited, and wherein epitactic hydroxyapatite crystallites with a crystallite size below a critical nucleus radius are formed on the prestructured collagen templates. 
     
     
         2 . A growth-inhibited hydroxyapatite according to  claim 1 , wherein the agglomerates are smaller than 1 μm and the crystallite size of the hydroxyapatite crystallites is 0.5 nm to 20 nm. 
     
     
         3 . A growth-inhibited hydroxyapatite according to  claim 1 , wherein the prestructured collagen templates are comprised of prestructured, denatured collagen, prestructured collagen molecules, prestructured collagen microfibrils, prestructured collagen fibrils, prestructured collagen analogs and/or prestructured collagen fragments and/or prestructured collagen derivatives, and wherein the prestructured collagen templates are <1 μm. 
     
     
         4 . A growth-inhibited hydroxyapatite according to  claim 1 , wherein the agglomerates of prestructured collagen templates are agglomerates of gelatin molecules, wherein the gelatin molecules have a diameter between 1.5 nm and 20 nm and the crystallite size of the hydroxyapatite crystallites is 1 nm to 5 nm. 
     
     
         5 . A growth-inhibited hydroxyapatite according to  claim 1  as an implant material or for coating implants. 
     
     
         6 . A growth-inhibited hydroxyapatite as an implant material or for coating implants, the growth-inhibited hydroxyapatite produced from prestructured collagen templates, denatured or broken up so that fibrillogenesis of the prestructured collagen templates is inhibited, wherein the prestructured collagen templates are capable of diffusion or migration, by mineralizing the prestructured collagen templates by incubating the prestructured collagen templates in supersaturated solutions containing Ca ions, wherein the Ca ions deposit in a predetermined way on the prestructured collagen templates, and by subsequently incubating the prestructured collagen templates in a phosphate-containing solution to grow epitactic hydroxyapatite crystallites on the prestructured collagen templates, wherein the Ca ions deposited in a predetermined way determine decisively growth inhibition of the hydroxyapatite crystallites, and by agglomerating the prestructured collagen templates with grown-on hydroxyapatite crystallites by diffusion or migration of the prestructured collagen templates, followed by separating the agglomerates.