Manufacture And Morphological Characterization Of Osteoconductive Porous Scaffolds

This paper discusses the manufacturing, chemical, and physical characterization of a three-dimensional porous scaffold developed for the repair of skeletal defects. Autografts; from patient donor sites are the current gold standard. However donor sites morbidity and a limited material supply restrict this treatment option. This is the main reason why the presence of synthetic biomaterials has grown significantly over the past two decades with applications in orthopedics. Bone consists of cortical and spongy regions both composed of Ca-8,Ca-3 (PO4)(4,3) (HPO4, CO3)(1,7) (OH,CO3)(0,3) mineral phase. Spongy bone is a highly spongy tissue (55-70% interconnected porosity) that allows the in-growth of the soft tissues and organic cells into the bone matrix. Chemically sub-micron and high phase-purity hydroxyapatite powders (HA: Ca-10(PO4)(6)(OH)(2)) were mixed, in a centrifuge ball mill, together with ethanol (EtOH) and hydroxypropyl-methyl-cellulose (HPMC) powders in appropriate amounts. The mixtures produced in this way were slowly dried in an oven. Dried powders were formed under pressure in cylindrical cakes and heated in an air atmosphere to the optimum sintering temperature. The raw materials and the scaffolds obtained by this technique were characterized by: XRD, laser granulometer, DSC-TGA analysis, FT-IR spectroscopy, SEM micrographs, and porosity measurements. This method produces porous HA scaffolds very similar to spongy bone from a chemical, physical and morphological point of view. The key parameters to the performance of the material for osteomimetic purposes will be analyzed and their effects studied also with reference to desirable modeling efforts.