Papers by Keyword: Subcutaneous Tissue

Abstract: Hydroxyapatite (HA) is widely used in bioceramic materials for bone grafting. HA scaffolds were synthesized using solid-state reaction method. Scaffolds were prepared by milling the elements of CaCO₃ and NH₄H₂PO₄ powders. The obtained powder was pressed with uniaxial pressing into a disc shape with the dimension of 4 mm in thickness and 16.5 mm in diameter under pressures 3 MPa and then sintering the samples at difference temperatures from 1100°C to 1300°C for 3 hours. This research aimed to produce phase HA scaffolds in order to find out the effects of sintering temperature on phase contents, density, porosity, hardness and bending strength, and to use optimized condition samples study with laboratory rats’ soft tissue to evaluate the soft tissue response to the samples. Thirty-two healthy in adults’ on non-gender-specific of Wistar rats were used in this study. Optimized, sintered samples were cut and lathed into a cylindrical shape. Sixty-four samples of optimized condition were implanted and left in subcutaneous tissue for 3, 7, 14, 21, 30, 45, 90 and 180 days. XRD, XRF, Archimedes technique, Vickers hardness and bending strength, as well as light microscopy, were used for analysis. The results of optimized condition have shown the bodies of sintered sample at 1300 °C for 3 hours had the highest content of 91.02 % HA phase, and the remaining phases of 4.51 % b-TCP and 4.47 % CaO, its bulk density and strength increased with increasing temperature, the highest bulk density of 2.006 ± 0.033 g/cm³, hardness of 30.02 ± 3.23 HV, bending strength of 9.07 ± 1.15 MPa. Sample reactions to soft tissues at 180 days were mild inflammatory cells, an absence of cellular infiltration, a presence of calcification, and absence of displacement of ceramic components into surrounding host tissue. Our results concluded that the samples were nontoxic to subcutaneous tissue and biocompatibility

Abstract: Porous granules without organic residues were produced from bovine medular anorganic bone. Sample showed carbonate content and crystalline order similar to natural bone. The cytotoxicity of anorganic bovine xenograft (Ossĕus®) was valuated from fibroblasts (1.5x104/cm2) cultured in serial diluted extract (0 – 100%) of Ossĕus plus 10% of fetal bovine serum (FBS). Pure extract (100%) reduced in 15% the number of viable cells (p<0.05, ANOVA, Tukey test) indicating very low cytotoxicity. Samples were implanted in the subcutaneous tissue of mice in order to evaluate tissue reaction. An organized connective tissue in contact to the granules was observed nine weeks after implantation. The anorganic bovine xenograft (Ossĕus®) was biocompatible and its behavior and osteoconduction potential should be evaluated in bony defects.

Abstract: The purpose of this study was to estimate influence of lysine for osteogenesis in the porous hydroxyapatite (HA) scaffolds with bone marrow cells. The HA scaffolds were soaked in 100mM concentration of lysine solution. They were kept in bone marrow cell suspension at 1×106 cells/ml density. Another HA scaffolds without immersion in lysine solution were kept in the cell suspension at 1×106 or 1×107 cells/ml density. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. In several sections, total pores and ones with bone were counted. Many pores containing bone were found in1×107 cells/ml concentration group. The significant difference was between 1×107 cells/ml group, the lysine group, and 1×106 cells/ml group. Although more bone formation was seen in lysine group than in 1×106 cells/ml group. There was no significant difference between the groups. Concentration of lysine to add in culture medium or scaffold should be improved respectively.

Abstract: The purpose of this study was to estimate hard tissue formation in two types of porous columnar hydroxyapatite (HA) in order to use as a scaffold for regeneration of dentine-pulp complex. Hard tissue formation in the columnar HA scaffold with a hollow center was compared to that in the columnar HA scaffold without a hollow center. The scaffolds were immersed in hyaluronic acid sodium salt solution and were soaked in bone marrow cell suspension. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. The scaffolds with a hollow center showed new hard tissue formation in many pores between the superficies and the wall of hollow. On the other hand, in the scaffolds without a hollow center, hard tissue formation was observed in only a few pores in the area near the external superficies. The results of this study suggested that the supply of nutrition and bioactive substance from the surrounding tissue were indispensable for differentiation of bone marrow cells and formation of new hard tissue in scaffold. A large contact area of a scaffold to the surrounding tissue may contribute to nutrition supply into the pores.