The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform

Suonghyu Hyon - One of the best experts on this subject based on the ideXlab platform.

  • long term Implantation Test and tumorigenicity of polyvinyl alcohol hydrogel plates
    Journal of Biomedical Materials Research, 2001
    Co-Authors: Tatsuo Nakamura, Hiroki Ueda, Tohru Tsuda, Yongho Li, Tetsuya Kiyotani, Masatoshi Inoue, Kazuya Matsumoto, Takashi Sekine, Liu Yu, Suonghyu Hyon
    Abstract:

    Two types of flat plates made from a polyvinyl alcohol (PVA) hydrogel with a water content of 80 and 20 (PVA-H80, PVA-H20), 20 × 10 × 1 mm in size, were subcutaneously implanted into each of 50 young, male Wistar rats. As a control, a sham operation was done on another set of 50 rats (Sham Op group). The shape and transparency of the PVA hydrogel were unchanged for up to 24 months. Tumors arose in 14 rats from the PVA-H80 group. In the PVA-H20 group, tumors appeared in 15 rats. The average tumor latency was 598 ± 109 days in the PVA-H80 and 637 ± 94 days in the PVA-H20. There was no difference in tumor incidence between the PVA-H20 and PVA-H80 groups (p < 0.05). In the Sham Op group, no malignant tumors appeared. Histopathologically, the tumors induced by hydrogel plates were malignant tumors resembling fibrosarcoma or malignant fibrous histiocytoma. This indicates that PVA hydrogel implants also induce solid state carcinogenesis at a similarly high rate to medical grade hydrophobic material reported in a previous study. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res 56: 289–296, 2001

Tatsuo Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • long term Implantation Test and tumorigenicity of polyvinyl alcohol hydrogel plates
    Journal of Biomedical Materials Research, 2001
    Co-Authors: Tatsuo Nakamura, Hiroki Ueda, Tohru Tsuda, Yongho Li, Tetsuya Kiyotani, Masatoshi Inoue, Kazuya Matsumoto, Takashi Sekine, Liu Yu, Suonghyu Hyon
    Abstract:

    Two types of flat plates made from a polyvinyl alcohol (PVA) hydrogel with a water content of 80 and 20 (PVA-H80, PVA-H20), 20 × 10 × 1 mm in size, were subcutaneously implanted into each of 50 young, male Wistar rats. As a control, a sham operation was done on another set of 50 rats (Sham Op group). The shape and transparency of the PVA hydrogel were unchanged for up to 24 months. Tumors arose in 14 rats from the PVA-H80 group. In the PVA-H20 group, tumors appeared in 15 rats. The average tumor latency was 598 ± 109 days in the PVA-H80 and 637 ± 94 days in the PVA-H20. There was no difference in tumor incidence between the PVA-H20 and PVA-H80 groups (p < 0.05). In the Sham Op group, no malignant tumors appeared. Histopathologically, the tumors induced by hydrogel plates were malignant tumors resembling fibrosarcoma or malignant fibrous histiocytoma. This indicates that PVA hydrogel implants also induce solid state carcinogenesis at a similarly high rate to medical grade hydrophobic material reported in a previous study. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res 56: 289–296, 2001

Jin-song Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Study on Cytocompatability and Animal Implantation Test of Foam SiC: Study on Cytocompatability and Animal Implantation Test of Foam SiC
    Journal of Inorganic Materials, 2010
    Co-Authors: Lin Wu, Xing-xiang Xu, Lu-zeng Wang, Xiao-fang Rong, Chong Tian, Jin-song Zhang
    Abstract:

    Foam SiC was prepared by macromolecule pyrogenation combined with reaction bonding method.The osteoblast-like cells MG63 were seeded and cultured in vitro on the foam SiC and observed under both SEM and TEM to further evaluate the cytocompatability of this novel material. The feasibility of the foam SiC as a bone replacement material for clinical treatment was also studied by establishing an animal model for repairing mandibular criticalsized defects in rabbits, and by using general observation, histological observation and bone histomorphometry.The results show that MG63 cells attach and grow well on the surface of the foam SiC, which indicates that the foam SiC is non-toxic and possesses good cytocompatibility. The 26 Tested rabbits are all in healthy conditions and the wounds are healed completely. The different degree of osteogenesis is observed on both periphery and inner mesh of the foam SiC at each time point, and the foam SiC shows no adverse effect to the process of bone repair. It is found that both the rate of tetracycline fluorescence labeling and the new bone area on the foam SiC are lower than those of hydroxyapatite (HA) after 4w Implantation, but there are no statistical differences after both 8w and 24w Implantations, indicating that the foam SiC should be similar to HA in osteo-conduction ability judging from the long-term repair effect to mandibular defects

Xu Xing - One of the best experts on this subject based on the ideXlab platform.

  • study on cytocompatability and animal Implantation Test of foam sic
    Journal of Inorganic Materials, 2010
    Co-Authors: Xu Xing
    Abstract:

    Foam SiC was prepared by macromolecule pyrogenation combined with reaction bonding method.The osteoblast-like cells MG63 were seeded and cultured in vitro on the foam SiC and observed under both SEM and TEM to further evaluate the cytocompatability of this novel material.The feasibility of the foam SiC as a bone replacement material for clinical treatment was also studied by establishing an animal model for repairing mandibular critical-sized defects in rabbits,and by using general observation,histological observation and bone histomorphometry.The results show that MG63 cells attach and grow well on the surface of the foam SiC,which indicates that the foam SiC is non-toxic and possesses good cytocompatibility.The 26 Tested rabbits are all in healthy conditions and the wounds are healed completely.The different degree of osteogenesis is observed on both periphery and inner mesh of the foam SiC at each time point,and the foam SiC shows no adverse effect to the process of bone repair.It is found that both the rate of tetracycline fluorescence labeling and the new bone area on the foam SiC are lower than those of hydroxyapatite(HA) after 4w Implantation,but there are no statistical differences after both 8w and 24w Implantations,indicating that the foam SiC should be similar to HA in osteo-conduction ability judging from the long-term repair effect to mandibular defects.

Akitada Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • comparative studies by cell culture and in vivo Implantation Test on the toxicity of natural rubber latex materials
    Journal of Biomedical Materials Research, 1992
    Co-Authors: Yoshiaki Ikarashi, Kazuhiro Toyoda, Naomi Ohsawa, Takao Uchima, Toshie Tsuchiya, Masaaki Kaniwa, Michio Sato, Michihito Takahashi, Akitada Nakamura
    Abstract:

    : Colony assay using V79 cells, the agar diffusion assay with L929 cells, and the 7-day rabbit muscle Implantation Test were employed to evaluate the cytotoxicity and tissue toxicity of natural rubber latex (NRL) materials. The in vivo Implantation Test showed that, among 13 histological parameters, thickness of inflammatory layer was the most useful index to evaluate tissue responses quantitatively. A comparison of the in vivo and in vitro parameters revealed the following correlations between the thickness of the inflammatory layer and cytotoxicity indices: Colony assay of the extracts, IC50: r = 0.80; Agar diffusion assay, Zone index: r = 0.73; Lysis index: r = 0.61. From these results, it appears that the colony assay provides a more reliable prediction of the tissue response than the agar diffusion assay.