Tripolyphosphate cross-linked macromolecular composites for the growth of shape- and size-controlled apatites.
Bioactive composites that enable the formation of calcium phosphates have received increased attention over the last decade, in the development of osteoconductive biomaterials for orthopaedic applications. In this work, tripolyphosphate (TPP)-cross-linked chitosan/gelatin composites (TPP-CG) were prepared for the growth of shape- and size-controlled calcium phosphates on/in the composites. The mineralization pattern of the composites, after soaking in the Ca(OH)(2) aqueous solution, clearly demonstrated oriented, needle-like nanocrystallites of calcium phosphates in the matrix with especially high Ca/P molar ratio (3.98) as detected by energy dispersive X-ray spectroscopy (EDX) analysis. Subsequent to mineralization in a simulated body fluid (SBF), the mineralized composites showed micro-scaled spherical aggregates deposited on the surface and granule-like nanocrystallites grew in the matrix. The Ca/P molar ratio (1.72) and X-ray diffraction pattern of the nanocrystallites grown in the composites were similar to those of hydroxyapatite (HAp). Osteoblastic differentiation of ROS cells cultured on the mineralized composites allowed an enhanced expression of the chosen osteogenic marker (alkaline phosphatase, ALPase). These results indicated that the composites mineralized with micro- and nano-scaled calcium phosphates with various structural features make them attractive for bone tissue engineering applications.
Department of Polymer Materials, Vanung University, Chung-Li, Taiwan.
Shu-Huei
SH
Yu
Shao-Jung
SJ
Wu
Jui-Yu
JY
Wu
Chih-Kang
CK
Peng
Fwu-Long
FL
Mi
D001031:Apatites / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry; D002460:Cell Line; D048271:Chitosan / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000737:chemistry / Q000166:cytology; D011122:Polyphosphates / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D023822:Tissue Engineering; D014961:X-Ray Diffraction
D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011122:Polyphosphates; D005780:Gelatin; D048271:Chitosan; C005692:triphosphoric acid