title: Formation of calcium phosphate/collagen composites through mineralization of collagen matrix.
abstract: Several types of calcium phosphate/collagen composites, including noncrystalline calcium phosphate/collagen, poorly crystalline carbonate-apatite (PCCA)/collagen, and PCCA + tetracalcium phosphate/collagen composites, were prepared through the mineralization of collagen matrix. The type I collagen was presoaked with a PO(3-)(4) containing solution and then immersed in a Ca(2+) containing solution to allow mineral deposition. The solution of 0.56 M sodium dibasic phosphate (Na(2)HPO(4)) with a pH of nearly 14 was metastable and its crystallization produced Na(2)HPO(4) and sodium tripolyphosphate hexahydrate (Na(5)P(3)O(10)). 6H(2)O), leading to a controlled release of orthophosphate ions during the subsequent mineral precipitation. The development of the composites was investigated in detail. The mineral contributed up to 60-70% of the weight of the final composites. The strength and Young's modulus of the composites in tensile tests overlapped the lower range of values reported for bone. When implanted in muscle tissue, the composite showed biodegradability that was partly through a multinucleated giant cell mediated process. In a bone explant culture model it was observed that bone-derived cells deposited mineralizing collagenous matrix on the composite.
authors.affiliation: Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: C
authors.initials: C
authors.lastname: Du
authors.forename: F Z
authors.initials: FZ
authors.lastname: Cui
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: Q L
authors.initials: QL
authors.lastname: Feng
authors.forename: X D
authors.initials: XD
authors.lastname: Zhu
authors.forename: K
authors.initials: K
authors.lastname: de Groot
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D003094:Collagen; D008855:Microscopy, Electron, Scanning; D009924:Organ Culture Techniques; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C030782:carboapatite; C485838:calcium phosphate, monobasic, anhydrous; D003094:Collagen; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous