Papers by Keyword: Osteoblast

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Authors: Viviane Gomide, Natália Ocarino, Rogéria Serakides, Maria de Fatima Leite, Marivalda Pereira
Abstract: Bioactive glass/polymer hybrids are promising materials for biomedical applications because they combine the bioactivity of these bioceramics with the flexibility of polymers. In previous work hybrid foams with 50% bioactive glass and 50% polyvinyl alcohol (PVA) were prepared by the sol-gel process for application as scaffold for bone tissue engineering. In this work the hybrid samples were tested in osteoblast culture to evaluate adhesion and proliferation. Samples were also implanted subcutaneously in the dorsal region of adult rats. The hybrid 50% PVA/bioactive glass foam was chosen as the best scaffold in the composition range studied and it is a promising material for bone repair, providing a good environment for the adhesion and proliferation of osteoblasts in vitro. Concerning the in vivo studies we can assure that the “foreing body” reaction was moderate and that the presence of osteoid indicated bone matrix formation.
671
Authors: Hua Wei He, Bo Li, Guang Da Li, Zhi Xiu He, Zhi Qing Chen
Abstract: This study sought to compare the biocompatibility of four dental ceramics so as to provide indications useful for the further development of dental materials. Osteoblasts were obtained by culturing the cranial explant of SD rat and cultured in vitro when they were seeded onto four different materials: hydroxyapatite, bioactive glass ceramics, tricalciumphosphate-hydroxyapatite and nano-hydroxyapatite (nHA). The phase contrast microscope and scanning electron microscope were used to evaluate the cell morphology and attachment. The content of alkaline phosphatase was calculated by molecular biological methods. MTT method was performed to find the alteration of proliferation. Then by use of wash way method, the adhesion ability was tested. The results showed that all of the four bioceramics had good cytocompatibility. There were significant differences among them on the levels of cell growth, differation and adhesion in vitro. The biocompatibility of nHA is the best and of conventional HA is the worst.
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Authors: Yan Mei Chen, Ting Fei Xi, Yu Dong Zheng, Yi Zao Wan
Abstract: The nanocomposite of nano-hydroxyapatite/bacterial cellulose (nHA/BC) obtained by depositing in simulated body fluid (SBF), incorporating their excellent mechanical and biological properties, is expected to have potential applications in bone tissue engineering. However, the biological response evaluation of biomaterials is required to provide useful information to improve their design and application. In this article, the in vitro cytotoxicity of composites nHA/BC as well as its degradation residues was studied. Scanning electron microscopy (SEM) was used to observe the morphology of original materials and their degradation residues. The degree of degradation was evalued by measuring the concentration of reducing sugar (glucose) by ultraviolet spectrophotometer. Bone-forming osteoblasts (OB) and infinite culture cell line L929 fibroblasts were used to measure the cytotocixity of materials with MTT assay. Both kinds of cells in infusion proliferate greatly in a normal form and their relative growth rate (RGR) exceeds by 75%, which shows the cytotoxicity of materials is graded as 0~1, according to the national standard. Nevertheless, bone-forming OB cells, as a kind of target cells, are more susceptive on the cytotoxicity than infinite culture fibroblast cells L929. The results suggest the nanocomposite of nHA/BC without cytotoxicity is greatly promising as a kind of scaffold materials for bone tissue engineering and tissue functional cells are more suited to evaluate the cytotoxicity of biomedical materials.
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Authors: Yusuke Nakashima, Michiyo Honda, Toshiisa Konishi, Minori Mizumoto, Mamoru Aizawa
Abstract: In our previous study, silicon-containing hydroxyapatite (Si-HAp) powder was prepared via an aqueous precipitation reaction. The Si-HAp powders were synthesized with desired Si contents (0, 0.4, 0.8, 1.6, and 2.4 mass%) as a nominal composition. Another previous study in our group demonstrated surface-modification of HAp powder with inositol phosphate (IP6) enhanced the compressive strength of apatite cement. Thus, to fabricate the cements with higher bioactivity, the above Si-HAp powders were surface-modified with IP6 (IP6-Si-HAp). The IP6-Si-HAp cements with various Si contents were fabricated by mixing with pure water at the powder/liquid ratio of 1/0.4 [w/v]. In order to clarify biocompatibility of the IP6-Si-HAP cements in the present work, MC3T3-E1 cells as a model of osteoblast were seeded on the cement specimens. As for the numbers of cells cultured on the IP6-Si-HAp cements, the substitution of lower levels of Si into HAp lattice did not greatly influence the cell proliferation. However, the substitution of Si amount over 0.8 mass% enhanced the cell proliferation. Especially, the IP6-Si-HAp cement with the Si content of 2.4 mass% showed excellent cell proliferation among examined specimens. Therefore, to fabricate the cements with higher bioactivity, it is necessary to control the amount of Si in the IP6-Si-HAp cements. The usage of these IP6-Si-HAp cements may make it possible to fabricate the cements with higher bioactivity, compare to conventional pure HAp cements.
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Authors: Q. Qiu, Paul Ducheyne, P.S. Ayyaswamy
467
Authors: Larry L. Hench, Julia M. Polak
Abstract: Historically the function of biomaterials has been to replace diseased, damaged and aged tissues. First generation biomaterials, including bio ceramics, were selected to be as inert as possible in order to minimize the thickness of interfacial scar tissue. Bioactive glasses provided an alternative from the 1970’s onward; second generation bioactive bonding of implants with tissues and no interfacial scar tissue. This chapter reviews the discovery that controlled release of biologically active Ca and Si ions from bioactive glasses leads to the up-regulation and activation of seven families of genes in osteoprogenitor cells that give rise to rapid bone regeneration. This finding offers the possibility of creating a new generation of gene activating bioceramics designed specially for tissue engineering and in situ regeneration of tissues.
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Authors: Larry L. Hench
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Authors: Bang Cheng Yang, Qi Feng Yu, Ji Yong Chen, Xing Dong Zhang
Abstract: The bioactivity of a composite of titania and hydroxyapatite was studied in vitro in this paper. After the titania ceramics was added 10% HA, it could induce apatite formation in simulated body fluid in 2d, while the pure titania ceramics could not induced apatite formation even after 14d. After the composite of titania and HA was subjected to alkali-heat treatment, it has a faster speed for apatite formation in SBF than the composite without treatment. When the osteoblast was cultured on the materials, the amount of osteoblasts attaching on the composite was more than that on the pure titania ceramics. It has the most osteoblasts cells on the composite subjected to alkali-heat treatment. These results showed that the composite of titania and HA is a bioactive materials, while the alkali-heat treatment could improved the bioactivity of this composite.
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Authors: Akimitsu Miyazaki, Mamoru Aizawa
Abstract: There are two crystal planes in hydroxyapatite (Ca10(PO4)6(OH)2; HAp) that is clinically applied to artificial bone or dental root. The two crystal planes, a- and c-planes, are anisotropy. We have successfully fabricated dense HAp ceramics with preferred orientation to a-plane from single-crystal apatite fibers (AF) and apatite gels (AG). We examined the cellular response, such as adhesion, proliferation and morphology, of orthoclastic MC3T3-E1 cells, to the surface of the HAp ceramics with preferred orientation to a-plane. The initial cell attachment efficiency of the HAp ceramics with a-plane was lower than that of isotropic HAp ceramics as a control. This may be due to the difference of surface potential of the examined HAp ceramics. The proliferation of cells cultured on the HAp ceramics with a-plane was almost the same as that of isotropic HAp one.
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Authors: U. Lohbauer, G. Jell, Priya Saravanapavan, Julian R. Jones, Larry L. Hench
Abstract: In dentistry, chronic periodontitis often leads to bone resorption together with an increasing risk of bacteremia. Bioactive glass has found extensive application as dental graft material. A successful antimicrobial bactericidal effect has been shown from the introduction of Ag2O into the glass composition. In this study, the cytotoxicity of soluble silver, calcium and silica ions on primary human osteoblasts was investigated by measurements of mitochondrial activity and neutral red dye uptake. Silver concentrations of 4 - 6 ppm (1 mg/ml conc.) and 6 - 9 ppm (2 mg/ml conc.) have been measured in complete culture medium. It was found that the bioactive gel-glass extract with an initial concentration of 1 mg/ml (1mg glass per ml of culture medium) has no negative effect, whereas increased gel-glass concentration of 2 mg/ml seemed to have a toxic effect on the cell viability of human osteoblasts. It might be concluded that a reduction of the rate of silver dissolution from the bioactive gel-glass might preserve a maximum cell viability.
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