Osteogenesis Depending on Geometry of Porous Hydroxyapatite Scaffolds

Abstract

The effect of the configuration of porous cylindrical hydroxyapatite (HA) scaffold and laminin preparation of the scaffold on bone formation was estimated. HA scaffolds with a hollow center of 2 or 4 mm in diameter and those without a hollow center were used. The scaffolds were immersed in laminin solution or in culture medium. Bone marrow cells were obtained from the femora of male Fischer 344 rats. Cell suspension was prepared at 1 x 10(6) cells/mL density. The cells were seeded into HA scaffolds. Each scaffold was implanted in the dorsal subcutis of rats for 4 weeks. Bone formation in scaffolds was observed histologically. The quantity of osteocalcin was measured immunochemically. Many pores containing bone were identified in the laminin-immersed HA scaffold with a hollow center measuring 4 mm in diameter than those without and those with a hollow center measuring 2 mm in diameter. A greater quantity of osteocalcin was detected in the HA scaffold with immersion in laminin than in that without immersion in laminin. However, the results of the immunochemical assay for osteocalcin showed that a hollow center in the scaffold did not contribute to bone formation compared to scaffolds without a hollow center. It is considered that laminin may act as an adhesive for effective cell attachment to the walls of the pores in an HA scaffold.

Calcified Nodule Formation <i>in Vitro</i> Using Rat Mandibular Incisor Pulp Cells

“…Based on our in vitro preliminary experiments, the period for dental pulp cell culture until calcified nodule formation from the primary culture may be long. In the previous in vivo and in vitro studies by Yoshikawa et al [5] [21][22][23], bone marrow cells from the femur of rats were used to examination hard tissue formation as a substitute for cells obtained from dental pulp. The proliferation of stem cells in dental pulp cells was not evaluated and osteogenic potential of bone marrow cells was not compared with hard tissue forming ability by dental pulp-derived cells in this study.…”

“…Stem cells may be used in the studies in vitro and in vivo for tooth regeneration, especially cells from tooth bud or dental pulp tissue. In these in vivo or in vitro studies for the regeneration of teeth, bone marrow cells were used [5,6]. However, it is not practical to obtain mesen-Open Access J. Biomedical Science and Engineering chymal stem cells from iliac bone marrow as in orthopedics [7] for tooth regeneration in dental practice, because the physical stress is severe for the patient.…”

Regulation of the protein-loading capacity of hydroxyapatite by mercaptosuccinic acid modification

“…After 15, 60, and 120 min, the slurry was centrifuged, and the amount of protein released from Mer-HAp in the supernatant was measured by BCA protein assay. To evaluate the effect of pH on the protein release from the protein-loaded Mer-HAp, the same study using a different pH solution controlled by 0.1 mol l À1 of HNO 3 and NaOH was carried out.…”

“…Hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAp: Ca/P molar ratio = 1.67), a calcium phosphate compound, is known for its excellent osteoconductivity, and has been extensively investigated as a biomaterial for both the reconstruction and regeneration of bone tissue [1][2][3]. To reconstruct bone, especially relatively large bone defects (e.g.…”

Bone Formation in a Scaffold Composed of Cylindrical Hydroxyapatite and Tryptophan- or Lysine-Coated Sponge <i>in Vivo</i>

“…A scaffold is necessary for bone and hard tissue regeneration because of their three-dimensional structure [1]. Cylindrical porous hydroxyapatite (HA) might be suitable as a scaffold in which mesenchymal stem cells differentiate into hard tissue-forming cells for the regeneration of bone or tooth [2]. However, a considerable number of mesenchymal stem cells are necessary for producing a sufficient amount of bone or tooth.…”