Preparation of porous apatite granules from calcium phosphate cement.
A versatile method for preparing spherical, micro- and macroporous (micro: 2-10 and macro: 150-550 microm pores), carbonated apatitic calcium phosphate (Ap-CaP) granules (2-4 mm in size) was developed by using NaCl crystals as the porogen. The entire granule production was performed between 21 and 37 degrees C. A CaP cement powder, comprising alpha-Ca3(PO4)2 (61 wt.%), CaHPO4 (26%), CaCO3 (10%) and precipitated hydroxyapatite, Ca10(PO4)6(OH)2 (3%), was dry mixed with NaCl crystals varying in size from 420 microm to 1 mm. Cement powder (35 wt.%) and NaCl (65 wt.%) mixture was kneaded with an ethanol-Na2HPO4 initiator solution, and the formed dough was immediately agitated on an automatic sieve shaker for a few minutes to produce the spherical granules. Embedded NaCl crystals were then leached out of the granules by soaking them in deionized water. CaP granules were micro- and macroporous with a total porosity of 50% or more. Granules were composed of carbonated, poorly crystallized, apatitic CaP phase. These were the first spherical and porous CaP granules ever produced from a self-setting calcium phosphate cement. The granules reached their final handling strength at the ambient temperature through the cement setting reaction, without having a need for sintering.
Tas
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Department of Biomedical Engineering, Yeditepe University, Istanbul 34755, Turkey. actas@yeditepe.edu.tr
D001031:Apatites / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D002516:Ceramics; D019245:Compressive Strength; D017886:Durapatite / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D016062:Porosity; D011208:Powders; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature
D001031:Apatites; D001672:Biocompatible Materials; D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011208:Powders; D012965:Sodium Chloride; D017886:Durapatite; C020243:calcium phosphate