title: Hierarchical pore structure of calcium phosphate scaffolds by a combination of gel-casting and multiple tape-casting methods.
abstract: The objective of this work was to design hierarchical pore structure scaffolds with potential applications in bone tissue regeneration. For that purpose, a bioceramic material such as biphasic calcium phosphate, which consists of a mixture of hydroxyapatite and beta-tricalcium phosphate, was selected. Multilayer pieces (MLP) with hierarchical pore structure were developed employing a new technique that combines gel casting and adding porogens, using multiple tape-casting methods. Pieces with functionally graded porosity were fabricated using porogens with different sizes. The porogens used were Porlat K85 and Porlat K86 with diameters <150 microm and 150-300 microm, respectively. Two types of sintered tapes, with different porosity, no cracking and enough interconnection size were selected. MLP with hierarchical pore structure were designed by the multiple tape-casting method. Interconnected pores whose sizes increase from interior tapes (1.6-3.6 microm) towards exterior tapes (20-51.5 microm) and interpenetration between tapes were achieved. Delamination or cracking were not observed after heat treatment. The flexural strength of pieces was investigated by the three-point bending test. This new combination of methods offers the possibility of manufacturing scaffolds with interconnected pore sizes ranging from 1.6 to 51.5 microm.
authors.affiliation: Facultad de Farmacia, Departamento de Química Inorgánica y Bioinorgánica, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Sánchez-Salcedo
authors.forename: J
authors.initials: J
authors.lastname: Werner
authors.forename: M
authors.initials: M
authors.lastname: Vallet-Regí
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry*; D004586:Electrophoresis; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010968:Plasticizers / Q000737:chemistry; D016062:Porosity; D011208:Powders / Q000737:chemistry; D012212:Rheology; D013057:Spectrum Analysis; D013535:Suspensions / Q000737:chemistry; D054457:Tissue Scaffolds; D014961:X-Ray Diffraction
chemical_list: D002130:Calcium Phosphates; D005782:Gels; D010968:Plasticizers; D011208:Powders; D013535:Suspensions; C020243:calcium phosphate