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Mohamed N Rahaman - One of the best experts on this subject based on the ideXlab platform.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications i preparation and in vitro Degradation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Mohamed N Rahaman, Xin Liu
    Abstract:

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the Degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78-82%; pore size = 100-500 microm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion Rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5-11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and Degradation Rate can be achieved by replacing varying amounts of SiO(2) in silicate bioactive glass with B2O3.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications ii in vitro and in vivo biological evaluation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Mohamed N Rahaman, Sonny B Bal, Lynda F Bonewald, Keiichi Kuroki, Roger F Brown
    Abstract:

    In Part I, the in vitro Degradation of bioactivAR52115e glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the boRate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and Degradation Rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substRates for the repair and regeneration of contained bone defects.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications i preparation and in vitro Degradation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Qiang Fu, Mohamed N Rahaman, Hailuo Fu
    Abstract:

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the Degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78–82%; pore size = 100–500 μm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion Rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5–11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and Degradation Rate can be achieved by replacing varying amounts of SiO2 in silicate bioactive glass with B2O3. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications ii in vitro and in vivo biological evaluation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Qiang Fu, Mohamed N Rahaman, Lynda F Bonewald, Keiichi Kuroki, Roger F Brown
    Abstract:

    In Part I, the in vitro Degradation of bioactive glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the boRate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and Degradation Rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substRates for the repair and regeneration of contained bone defects. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Roger F Brown - One of the best experts on this subject based on the ideXlab platform.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications ii in vitro and in vivo biological evaluation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Mohamed N Rahaman, Sonny B Bal, Lynda F Bonewald, Keiichi Kuroki, Roger F Brown
    Abstract:

    In Part I, the in vitro Degradation of bioactivAR52115e glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the boRate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and Degradation Rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substRates for the repair and regeneration of contained bone defects.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications ii in vitro and in vivo biological evaluation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Qiang Fu, Mohamed N Rahaman, Lynda F Bonewald, Keiichi Kuroki, Roger F Brown
    Abstract:

    In Part I, the in vitro Degradation of bioactive glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the boRate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and Degradation Rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substRates for the repair and regeneration of contained bone defects. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Anna Schnurer - One of the best experts on this subject based on the ideXlab platform.

  • the microbial community structure in industrial biogas plants influences the Degradation Rate of straw and cellulose in batch tests
    Biotechnology for Biofuels, 2016
    Co-Authors: Li Sun, Tong Liu, Bettina Muller, Anna Schnurer
    Abstract:

    Materials rich in lignocellulose, such as straw, are abundant, cheap and highly interesting for biogas production. However, the complex structure of lignocellulose is difficult for microbial cellulolytic enzymes to access, limiting Degradation. The Rate of Degradation depends on the activity of members of the microbial community, but the knowledge of this community in the biogas process is rather limited. This study, therefore, investigated the Degradation Rate of cellulose and straw in batch cultivation test initiated with inoculums from four co-digestion biogas plants (CD) and six wastewater treatment plants (WWTP). The results were correlated to the bacterial community by 454-pyrosequencing targeting 16S rRNA gene and by T-RFLP analysis targeting genes of glycoside hydrolase families 5 (cel5) and 48 (cel48), combined with construction of clone libraries UniFrac principal coordinate analysis of 16S rRNA gene amplicons revealed a clustering of WWTPs, while the CDs were more sepaRated from each other. Bacteroidetes and Firmicutes dominated the community with a comparably higher abundance of the latter in the processes operating at high ammonia levels. Sequences obtained from the cel5 and cel 48 clone libraries were also mainly related to the phyla Firmicutes and Bacteroidetes and here ammonia was a parameter with a strong impact on the cel5 community. The results from the batch cultivation showed similar Degradation pattern for eight of the biogas plants, while two characterised by high ammonia level and low bacterial diversity, showed a clear lower Degradation Rate. Interestingly, two T-RFs from the cel5 community were positively correlated to high Degradation Rates of both straw and cellulose. One of the respective partial cel5 sequences shared 100 % identity to Clostridium cellulolyticum. The Degradation Rate of cellulose and straw varied in the batch tests dependent on the origin of the inoculum and was negatively correlated with the ammonia level. The cellulose-degrading community, targeted by analysis of the glycoside hydrolase families 5 (cel5) and 48 (cel48), showed a dominance of bacteria belonging the Firmicutes and Bacteriodetes, and a positive correlation was found between the cellulose Degradation Rate of wheat straw with the level of C. cellulolyticum.

  • the microbial community structure in industrial biogas plants influences the Degradation Rate of straw and cellulose in batch tests
    Biotechnology for Biofuels, 2016
    Co-Authors: Li Sun, Tong Liu, Bettina Muller, Anna Schnurer
    Abstract:

    Background Materials rich in lignocellulose, such as straw, are abundant, cheap and highly interesting for biogas production. However, the complex structure of lignocellulose is difficult for microbial cellulolytic enzymes to access, limiting Degradation. The Rate of Degradation depends on the activity of members of the microbial community, but the knowledge of this community in the biogas process is rather limited. This study, therefore, investigated the Degradation Rate of cellulose and straw in batch cultivation test initiated with inoculums from four co-digestion biogas plants (CD) and six wastewater treatment plants (WWTP). The results were correlated to the bacterial community by 454-pyrosequencing targeting 16S rRNA gene and by T-RFLP analysis targeting genes of glycoside hydrolase families 5 (cel5) and 48 (cel48), combined with construction of clone libraries

Qiang Fu - One of the best experts on this subject based on the ideXlab platform.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications i preparation and in vitro Degradation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Qiang Fu, Mohamed N Rahaman, Hailuo Fu
    Abstract:

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the Degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78–82%; pore size = 100–500 μm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion Rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5–11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and Degradation Rate can be achieved by replacing varying amounts of SiO2 in silicate bioactive glass with B2O3. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  • silicate borosilicate and boRate bioactive glass scaffolds with controllable Degradation Rate for bone tissue engineering applications ii in vitro and in vivo biological evaluation
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Qiang Fu, Mohamed N Rahaman, Lynda F Bonewald, Keiichi Kuroki, Roger F Brown
    Abstract:

    In Part I, the in vitro Degradation of bioactive glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a boRate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the boRate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and Degradation Rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substRates for the repair and regeneration of contained bone defects. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Deli Dong - One of the best experts on this subject based on the ideXlab platform.

  • the influence of lactic on the properties of poly glycerol sebacate lactic acid
    Materials Science and Engineering: C, 2009
    Co-Authors: Zhijie Sun, Wei Huang, Xiaolan Zhang, Baofeng Yang, Yufeng Zheng, Deli Dong
    Abstract:

    Abstract We synthesized a series of poly (glycerol, sebacate and lactic acid) (PGSL) with 1:1:0, 1:1:0.25, 1:1:0.5, 1:1:1 mole ratio of glycerol, sebacate and lactic acid, in order to elucidate the relation of microstructure to the Degradation Rate and mechanical properties. The microstructure of the polymer with lactic acid in the ratio of 0.25 displayed phase separation structure. The crystallization temperature ( T c ) and absolute crystallization enthalpy (Δ H c ) of PGSL tended to decrease with the increasing ratio of lactic acid. Degradation Rate of PGSL with lactic acid in the ratio of 0.25 was fastest in vitro and 35% mass loss occurred after 60 day Degradation. In the range of 0, 0.5 and 1, the Degradation Rate decreased slightly with the lactic acid increasing and 18% mass loss occurred after 60 day Degradation when lactic acid was doped in the ratio of 1.0. All PGSL polymers inhibited platelet adhesion, prolonged whole blood clotting time, activated partial thromboplastin time and prothrombin time. In conclusion, doping lactic acid can modulate the microstructure of poly (glycerol, sebacate) (PGS), thereby control the Degradation Rate and mechanical property of PGS.