Preparation Of HA Scaffold With Interconnected Spherical Macrospores

In bone tissue engineering, a scaffolding material is used either to induce formation of bone from the surrounding tissue or to act as a carrier or template for implanted bone cells or other agents. To serve as a scaffold, the material must be biocompatible, and have enough mechanical strength to provide structural support during the bone growth and remodeling. Hydroxyapatite (HA, Ca₁₀(PO4)₆(OH)₂) scaffolds with reticulate pore structure has good biocompaty, which widely used in surgery, but it has low mechanical strength for the reticulate pore structure. Spherical pore structure could disperse the stress when it load, avoid stress focus, improve the mechanics property.In this study, HA scaffold with interconnected spherical macrospores was fabericated by the process of polymer template made and immit slurry. The pore morphology, size, and size distribution of scaffolds were characterized using scanning electron microscope (SEM). X-ray diffraction (XRD) and infrared spectroscopy (1R) were used to characterize the crystal structure and chemical composition, respectively. Mechanical properties were performed using an Instron test machine to measures the compress strength. The results shows that:The interconnected porous HA scaffold with a control of pore size 100～800μm and 40%～90% porosity could be achieved by casting and sintering. Proper NaCl particles size would improve the penetrability of interconnected spherical pore HA scaffold. The total porosity correlate with the volume content of NaCl particles (V_NaCl/V) linearly, so the porosity and pore diameter can be controlled by controlling the polymer spheres size and its volume contentsThe compressive strength increases with reducing the porosity and correlating with the porosity by a quadratic with certain pore diameter, thus it can be predicted by V_NaCl/V. A compressive strength of 8MPa (65% porosity, 200μm pore diameter) equivalent to that of cortical bone were achieved.Vitro cellular assay indicates that HA porous scaffold have a good compatibleness .With the decreasing of the porosity and the size of porous sphere , absorptivity to cell of HA porous scaffold has decreased gradually.