The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Takahiro Ogawa - One of the best experts on this subject based on the ideXlab platform.
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an understanding of the mechanism that promotes adhesion between roughened titanium implants and Mineralized Tissue
Journal of Biomechanical Engineering-transactions of The Asme, 2009Co-Authors: Jaewoo Shim, Takahiro Ogawa, Hiromi Nakamura, Vijay GuptaAbstract:A previously developed laser spallation technique to determine the tensile strength of thin film interfaces was successfully adopted to study the effect of microsurface roughness of titanium disks on the adhesion strength of Mineralized bone Tissue. The study demonstrated that Mineralized Tissue has about 25% higher interfacial strength when it is cultured on the acid-etched titanium surface than on its machined counterpart. Specifically, interfacial tensile strength of 179 ± 4.4 MPa and 224 ± 2.6 MPa were measured when the Mineralized Tissue was processed on the machined titanium and acid-etched titanium surfaces, respectively. Since in the laser spallation experiment, the Mineralized Tissue is pulled normal to the interface, this increase is attributed to the stronger interfacial bonding on account of higher surface energy associated with the acid-etched surface. This enhanced local chemical bonding further enhances the roughness-related mechanical interlocking effect. These two effects at very different length scales― atomic (enhanced bonding) versus continuum (roughness-related interlocking)―act synergistically and explain the widely observed clinical success of roughened dental implants.
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a role for proteoglycans in Mineralized Tissue titanium adhesion
Journal of Dental Research, 2007Co-Authors: Hiromi Nakamura, Frank Butz, L Saruwatari, Takahiro OgawaAbstract:Biomechanical properties of the bone-titanium interface have rarely been studied, due to the technical limitations involved; whether biological bonding mechanisms exist has not been determined. We hypothesized that a selected set of proteoglycan/glycosaminoglycan complexes plays a role in establishing the adhesion between bone and titanium, and utilized the rat bone-marrow-derived osteoblastic culture model to gain an insight into the hypothesis. Gene expression of selected proteoglycan core proteins was up-regulated in the osteoblasts cultured on titanium compared with those on polystyrene. Various sulfated glycosaminoglycans were immunochemically localized at Mineralized Tissue-titanium interfaces. The administration of various glycosaminoglycan-degrading enzymes into the cultures resulted in a 25–45% reduction of the Tissue-titanium interfacial strength, measured by a nanoscratch test; while the hardness and elastic modulus of the Mineralized Tissue, evaluated by nano-indentation, were not altered. In ...
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glycosaminoglycan degradation reduces Mineralized Tissue titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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Glycosaminoglycan degradation reduces Mineralized Tissue–titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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osteoblasts generate harder stiffer and more delamination resistant Mineralized Tissue on titanium than on polystyrene associated with distinct Tissue micro and ultrastructure
Journal of Bone and Mineral Research, 2005Co-Authors: Lei Saruwatari, Frank Butz, Hideki Aita, Hiromi Nakamura, Jianyong Ouyang, Yang Yang, Wenan Chiou, Takahiro OgawaAbstract:This study revealed that osteoblasts generate harder, stiffer, and more delamination-resistant Mineralized Tissue on titanium than on the Tissue culture polystyrene, associated with modulated gene expression, uniform mineralization, well-crystallized interfacial calcium-phosphate layer, and intensive collagen deposition. Knowledge of this titanium-induced alteration of osteogenic potential leading to enhanced intrinsic biomechanical properties of Mineralized Tissue provides novel opportunities and implications for understanding and improving bone-titanium integration and engineering physiomechanically tolerant bone. Introduction: Bone-titanium integration is a biological phenomenon characterized by continuous generation and preservation of peri-implant bone and serves as endosseous anchors against endogenous and exogenous loading, of which mechanisms are poorly understood. This study determines the intrinsic biomechanical properties and interfacial strength of cultured Mineralized Tissue on titanium and characterizes the Tissue structure as possible contributing factors in biomechanical modulation. Materials and Methods: Rat bone marrow-derived osteoblastic cells were cultured either on a Tissue culture-grade polystyrene dish or titanium-coated polystyrene dish having comparable surface topography. Nano-indentation and nano-scratch tests were undertaken on Mineralized Tissues cultured for 28 days to evaluate its hardness, elastic modulus, and critical load (force required to delaminate Tissue). Gene expression was analyzed using RT-PCR. The Tissue structural properties were examined by scanning electron microscopy (SEM), collagen colorimetry and localization with Sirius red stain, mineral quantification, and localization with von Kossa stain and transmission electron microscopy (TEM). Results: Hardness and elastic modulus of Mineralized Tissue on titanium were three and two times greater, respectively, than those on the polystyrene. Three times greater force was required to delaminate the Tissue on titanium than that on the polystyrene. SEM of the polystyrene culture displayed a porous structure consisting of fibrous and globular components, whereas the titanium Tissue culture appeared to be uniformly solid. Cell proliferation was remarkably reduced on titanium. Microscopic observations revealed that the Mineralized Tissue on titanium was composed of uniform collagen-supported mineralization from the titanium interface to the outer surface, with intensive collagen deposition at Tissue-titanium interface. In contrast, Tissue on the polystyrene was characterized by collagen-deficient mineralization at the polystyrene interface and calcium-free collagenous matrix formation in the outer Tissue area. Such characteristic microstructure of titanium-associated Tissue was corresponded with upregulated gene expression of collagen I and III, osteopontin, and osteocalcin mRNA. Cross-sectional TEM revealed the apposition of a high-contrast and well-crystallized calcium phosphate layer at the titanium interface but not at the polystyrene interface. Conclusions: Culturing osteoblasts on titanium, compared with polystyrene, enhances the hardness, elastic modulus, and interfacial strength of Mineralized Tissue to a higher degree. Titanium per se possesses an ability to alter cellular phenotypes and Tissue micro- and ultrastructure that result in enhanced intrinsic biomechanical properties of Mineralized Tissue.
Hiromi Nakamura - One of the best experts on this subject based on the ideXlab platform.
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an understanding of the mechanism that promotes adhesion between roughened titanium implants and Mineralized Tissue
Journal of Biomechanical Engineering-transactions of The Asme, 2009Co-Authors: Jaewoo Shim, Takahiro Ogawa, Hiromi Nakamura, Vijay GuptaAbstract:A previously developed laser spallation technique to determine the tensile strength of thin film interfaces was successfully adopted to study the effect of microsurface roughness of titanium disks on the adhesion strength of Mineralized bone Tissue. The study demonstrated that Mineralized Tissue has about 25% higher interfacial strength when it is cultured on the acid-etched titanium surface than on its machined counterpart. Specifically, interfacial tensile strength of 179 ± 4.4 MPa and 224 ± 2.6 MPa were measured when the Mineralized Tissue was processed on the machined titanium and acid-etched titanium surfaces, respectively. Since in the laser spallation experiment, the Mineralized Tissue is pulled normal to the interface, this increase is attributed to the stronger interfacial bonding on account of higher surface energy associated with the acid-etched surface. This enhanced local chemical bonding further enhances the roughness-related mechanical interlocking effect. These two effects at very different length scales― atomic (enhanced bonding) versus continuum (roughness-related interlocking)―act synergistically and explain the widely observed clinical success of roughened dental implants.
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a role for proteoglycans in Mineralized Tissue titanium adhesion
Journal of Dental Research, 2007Co-Authors: Hiromi Nakamura, Frank Butz, L Saruwatari, Takahiro OgawaAbstract:Biomechanical properties of the bone-titanium interface have rarely been studied, due to the technical limitations involved; whether biological bonding mechanisms exist has not been determined. We hypothesized that a selected set of proteoglycan/glycosaminoglycan complexes plays a role in establishing the adhesion between bone and titanium, and utilized the rat bone-marrow-derived osteoblastic culture model to gain an insight into the hypothesis. Gene expression of selected proteoglycan core proteins was up-regulated in the osteoblasts cultured on titanium compared with those on polystyrene. Various sulfated glycosaminoglycans were immunochemically localized at Mineralized Tissue-titanium interfaces. The administration of various glycosaminoglycan-degrading enzymes into the cultures resulted in a 25–45% reduction of the Tissue-titanium interfacial strength, measured by a nanoscratch test; while the hardness and elastic modulus of the Mineralized Tissue, evaluated by nano-indentation, were not altered. In ...
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glycosaminoglycan degradation reduces Mineralized Tissue titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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Glycosaminoglycan degradation reduces Mineralized Tissue–titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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osteoblasts generate harder stiffer and more delamination resistant Mineralized Tissue on titanium than on polystyrene associated with distinct Tissue micro and ultrastructure
Journal of Bone and Mineral Research, 2005Co-Authors: Lei Saruwatari, Frank Butz, Hideki Aita, Hiromi Nakamura, Jianyong Ouyang, Yang Yang, Wenan Chiou, Takahiro OgawaAbstract:This study revealed that osteoblasts generate harder, stiffer, and more delamination-resistant Mineralized Tissue on titanium than on the Tissue culture polystyrene, associated with modulated gene expression, uniform mineralization, well-crystallized interfacial calcium-phosphate layer, and intensive collagen deposition. Knowledge of this titanium-induced alteration of osteogenic potential leading to enhanced intrinsic biomechanical properties of Mineralized Tissue provides novel opportunities and implications for understanding and improving bone-titanium integration and engineering physiomechanically tolerant bone. Introduction: Bone-titanium integration is a biological phenomenon characterized by continuous generation and preservation of peri-implant bone and serves as endosseous anchors against endogenous and exogenous loading, of which mechanisms are poorly understood. This study determines the intrinsic biomechanical properties and interfacial strength of cultured Mineralized Tissue on titanium and characterizes the Tissue structure as possible contributing factors in biomechanical modulation. Materials and Methods: Rat bone marrow-derived osteoblastic cells were cultured either on a Tissue culture-grade polystyrene dish or titanium-coated polystyrene dish having comparable surface topography. Nano-indentation and nano-scratch tests were undertaken on Mineralized Tissues cultured for 28 days to evaluate its hardness, elastic modulus, and critical load (force required to delaminate Tissue). Gene expression was analyzed using RT-PCR. The Tissue structural properties were examined by scanning electron microscopy (SEM), collagen colorimetry and localization with Sirius red stain, mineral quantification, and localization with von Kossa stain and transmission electron microscopy (TEM). Results: Hardness and elastic modulus of Mineralized Tissue on titanium were three and two times greater, respectively, than those on the polystyrene. Three times greater force was required to delaminate the Tissue on titanium than that on the polystyrene. SEM of the polystyrene culture displayed a porous structure consisting of fibrous and globular components, whereas the titanium Tissue culture appeared to be uniformly solid. Cell proliferation was remarkably reduced on titanium. Microscopic observations revealed that the Mineralized Tissue on titanium was composed of uniform collagen-supported mineralization from the titanium interface to the outer surface, with intensive collagen deposition at Tissue-titanium interface. In contrast, Tissue on the polystyrene was characterized by collagen-deficient mineralization at the polystyrene interface and calcium-free collagenous matrix formation in the outer Tissue area. Such characteristic microstructure of titanium-associated Tissue was corresponded with upregulated gene expression of collagen I and III, osteopontin, and osteocalcin mRNA. Cross-sectional TEM revealed the apposition of a high-contrast and well-crystallized calcium phosphate layer at the titanium interface but not at the polystyrene interface. Conclusions: Culturing osteoblasts on titanium, compared with polystyrene, enhances the hardness, elastic modulus, and interfacial strength of Mineralized Tissue to a higher degree. Titanium per se possesses an ability to alter cellular phenotypes and Tissue micro- and ultrastructure that result in enhanced intrinsic biomechanical properties of Mineralized Tissue.
Frank Butz - One of the best experts on this subject based on the ideXlab platform.
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a role for proteoglycans in Mineralized Tissue titanium adhesion
Journal of Dental Research, 2007Co-Authors: Hiromi Nakamura, Frank Butz, L Saruwatari, Takahiro OgawaAbstract:Biomechanical properties of the bone-titanium interface have rarely been studied, due to the technical limitations involved; whether biological bonding mechanisms exist has not been determined. We hypothesized that a selected set of proteoglycan/glycosaminoglycan complexes plays a role in establishing the adhesion between bone and titanium, and utilized the rat bone-marrow-derived osteoblastic culture model to gain an insight into the hypothesis. Gene expression of selected proteoglycan core proteins was up-regulated in the osteoblasts cultured on titanium compared with those on polystyrene. Various sulfated glycosaminoglycans were immunochemically localized at Mineralized Tissue-titanium interfaces. The administration of various glycosaminoglycan-degrading enzymes into the cultures resulted in a 25–45% reduction of the Tissue-titanium interfacial strength, measured by a nanoscratch test; while the hardness and elastic modulus of the Mineralized Tissue, evaluated by nano-indentation, were not altered. In ...
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Glycosaminoglycan degradation reduces Mineralized Tissue–titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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glycosaminoglycan degradation reduces Mineralized Tissue titanium interfacial strength
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Hiromi Nakamura, Frank Butz, Hideki Aita, Jaewoo Shim, Vijay Gupta, Takahiro OgawaAbstract:Although the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between Mineralized Tissue and titanium having different surface topographies. Rat bone marrow-derived osteoblastic cells were cultured on either a machined titanium disk or an acid-etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the Tissue–titanium interfacial strength. In this technique, a laser-generated stress wave is used to separate the Tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the Tissue. Mineralized Tissue cultured on the acid-etched titanium showed 20–30% higher Tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid-etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the Mineralized Tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post-spallation Tissue remnant on the titanium substrates when treated with the enzymes. The Tissue remnant was greater in amount on the acid-etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the Mineralized Tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
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osteoblasts generate harder stiffer and more delamination resistant Mineralized Tissue on titanium than on polystyrene associated with distinct Tissue micro and ultrastructure
Journal of Bone and Mineral Research, 2005Co-Authors: Lei Saruwatari, Frank Butz, Hideki Aita, Hiromi Nakamura, Jianyong Ouyang, Yang Yang, Wenan Chiou, Takahiro OgawaAbstract:This study revealed that osteoblasts generate harder, stiffer, and more delamination-resistant Mineralized Tissue on titanium than on the Tissue culture polystyrene, associated with modulated gene expression, uniform mineralization, well-crystallized interfacial calcium-phosphate layer, and intensive collagen deposition. Knowledge of this titanium-induced alteration of osteogenic potential leading to enhanced intrinsic biomechanical properties of Mineralized Tissue provides novel opportunities and implications for understanding and improving bone-titanium integration and engineering physiomechanically tolerant bone. Introduction: Bone-titanium integration is a biological phenomenon characterized by continuous generation and preservation of peri-implant bone and serves as endosseous anchors against endogenous and exogenous loading, of which mechanisms are poorly understood. This study determines the intrinsic biomechanical properties and interfacial strength of cultured Mineralized Tissue on titanium and characterizes the Tissue structure as possible contributing factors in biomechanical modulation. Materials and Methods: Rat bone marrow-derived osteoblastic cells were cultured either on a Tissue culture-grade polystyrene dish or titanium-coated polystyrene dish having comparable surface topography. Nano-indentation and nano-scratch tests were undertaken on Mineralized Tissues cultured for 28 days to evaluate its hardness, elastic modulus, and critical load (force required to delaminate Tissue). Gene expression was analyzed using RT-PCR. The Tissue structural properties were examined by scanning electron microscopy (SEM), collagen colorimetry and localization with Sirius red stain, mineral quantification, and localization with von Kossa stain and transmission electron microscopy (TEM). Results: Hardness and elastic modulus of Mineralized Tissue on titanium were three and two times greater, respectively, than those on the polystyrene. Three times greater force was required to delaminate the Tissue on titanium than that on the polystyrene. SEM of the polystyrene culture displayed a porous structure consisting of fibrous and globular components, whereas the titanium Tissue culture appeared to be uniformly solid. Cell proliferation was remarkably reduced on titanium. Microscopic observations revealed that the Mineralized Tissue on titanium was composed of uniform collagen-supported mineralization from the titanium interface to the outer surface, with intensive collagen deposition at Tissue-titanium interface. In contrast, Tissue on the polystyrene was characterized by collagen-deficient mineralization at the polystyrene interface and calcium-free collagenous matrix formation in the outer Tissue area. Such characteristic microstructure of titanium-associated Tissue was corresponded with upregulated gene expression of collagen I and III, osteopontin, and osteocalcin mRNA. Cross-sectional TEM revealed the apposition of a high-contrast and well-crystallized calcium phosphate layer at the titanium interface but not at the polystyrene interface. Conclusions: Culturing osteoblasts on titanium, compared with polystyrene, enhances the hardness, elastic modulus, and interfacial strength of Mineralized Tissue to a higher degree. Titanium per se possesses an ability to alter cellular phenotypes and Tissue micro- and ultrastructure that result in enhanced intrinsic biomechanical properties of Mineralized Tissue.
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enhanced Mineralized Tissue adhesion to titanium over polystyrene assessed by the nano scratch test
Journal of Biomedical Materials Research Part A, 2005Co-Authors: Frank Butz, Hideki Aita, Kazuo Takeuchi, Takahiro OgawaAbstract:The critical load determined by the scratch test is regarded to be a representative measure of coating adhesion in the field of engineering. This study aimed to evaluate the method for its usefulness for assessing the Mineralized Tissue-titanium interface strength. Osteoblastic cells derived from rat bone marrow were cultured on polystyrene, titanium-coated polystyrene, and titanium disks with either a machined or dual-acid etched surface. Nano-scratch testing was performed on Mineralized Tissue specimens at culture day 28. The scratch path was monitored by light microscopy until complete delamination of Mineralized Tissue from the substrate occurred, and the required force was recorded as the critical load. Energy-dispersive spectroscopic analysis was used to verify the delamination. The mean critical load values (± standard deviations) were as follows: polystyrene 31 mN (±1), titanium-coated polystyrene 67 mN (±4), machined titanium 76 mN (±4), DAE titanium 107 mN (±3), with statistical differences (P < 0.05; ANOVA). No elemental calcium and phosphorous were observed in the delaminated areas. The nano-scratch test applied to cultured Mineralized Tissue differentiated the critical load from various culture conditions: polystyrene vs. titanium; titanium with different surface topographies. Culturing Mineralized Tissue on titanium, especially on roughened surfaces, increased the Tissue critical load. The nano-scratch test may be useful to evaluate Mineralized Tissue adhesion properties in titanium cultures. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Pamela C Yelick - One of the best experts on this subject based on the ideXlab platform.
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identification of adult Mineralized Tissue zebrafish mutants
Genesis, 2011Co-Authors: Viktoria Andreeva, Michelle H Connolly, Caitlin Stewartswift, Daniel Fraher, Jeffrey Burt, Justin Cardarelli, Pamela C YelickAbstract:Zebrafish craniofacial, skeletal, and tooth development closely resembles that of higher vertebrates. Our goal is to identify viable adult zebrafish mutants that can be used as models for human Mineralized craniofacial, dental, and skeletal system disorders. We utilized a large-scale forward-genetic chemical N-ethyl-nitroso-urea (ENU) mutagenesis screen to identify 17 early lethal homozygous recessive mutants with defects in craniofacial cartilage elements, and 7 adult homozygous recessive mutants with Mineralized Tissue phenotypes including craniofacial shape defects, fused sutures, dysmorphic or missing skeletal elements, scoliosis, and neural arch defects. One mutant displayed both an early lethal homozygous phenotype and an adult heterozygous phenotype. These results extend the utility of the zebrafish model beyond the embryo, to study human bone and cartilage disorders.
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accurately shaped tooth bud cell derived Mineralized Tissue formation on silk scaffolds
Tissue Engineering Part A, 2008Co-Authors: Wanpeng Xu, Weibo Zhang, Rose Asrican, David L Kaplan, Pamela C YelickAbstract:Based on the successful use of silk scaffolds in bone Tissue engineering, we examined their utility for Mineralized dental Tissue engineering. Four types of hexafluoroisopropanol (HFIP) silk scaffolds–(250 and 550 μm diameter pores, with or without arginine-glycine-aspartic acid (RGD) peptide) were seeded with cultured 4-day postnatal rat tooth bud cells and grown in the rat omentum for 20 weeks. Analyses of harvested implants revealed the formation of bioengineered Mineralized Tissue that was most robust in 550 μm pore RGD-containing scaffolds and least robust in 250 μm pore sized scaffolds without RGD. The size and shape of the silk scaffold pores appeared to guide Mineralized Tissue formation, as revealed using polarized light imaging of collagen fiber alignment along the scaffold surfaces. This study is the first to characterize bioengineered Tissues generated from tooth bud cells seeded onto silk scaffolds and indicates that silk scaffolds may be useful in forming Mineralized osteodentin of specified...
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Accurately Shaped Tooth Bud Cell–Derived Mineralized Tissue Formation on Silk Scaffolds
Tissue Engineering Part A, 2008Co-Authors: Wanpeng Xu, Weibo Zhang, Rose Asrican, David L Kaplan, Pamela C YelickAbstract:Based on the successful use of silk scaffolds in bone Tissue engineering, we examined their utility for Mineralized dental Tissue engineering. Four types of hexafluoroisopropanol (HFIP) silk scaffolds–(250 and 550 μm diameter pores, with or without arginine-glycine-aspartic acid (RGD) peptide) were seeded with cultured 4-day postnatal rat tooth bud cells and grown in the rat omentum for 20 weeks. Analyses of harvested implants revealed the formation of bioengineered Mineralized Tissue that was most robust in 550 μm pore RGD-containing scaffolds and least robust in 250 μm pore sized scaffolds without RGD. The size and shape of the silk scaffold pores appeared to guide Mineralized Tissue formation, as revealed using polarized light imaging of collagen fiber alignment along the scaffold surfaces. This study is the first to characterize bioengineered Tissues generated from tooth bud cells seeded onto silk scaffolds and indicates that silk scaffolds may be useful in forming Mineralized osteodentin of specified...
Takashi Okiji - One of the best experts on this subject based on the ideXlab platform.
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strontium ranelate promotes odonto osteogenic differentiation mineralization of dental papillae cells in vitro and Mineralized Tissue formation of the dental pulp in vivo
Scientific Reports, 2018Co-Authors: Alamuddin Bakhit, Nobuyuki Kawashima, Kentaro Hashimoto, Sonoko Noda, Keisuke Nara, Masashi Kuramoto, Kento Tazawa, Takashi OkijiAbstract:This study examined the effects and mechanisms of strontium ranelate (SrRn)—a drug used to treat osteoporosis—on the proliferation and differentiation/mineralization of cloned dental pulp-like cells (mouse dental papillae cells; MDPs). It also determined whether topical application of SrRn to exposed dental pulp Tissue promotes the formation of Mineralized Tissue in vivo. The MDPs were cultured with or without SrRn, and cell proliferation, odonto-/osteoblastic gene expression, Mineralized nodule formation, and Akt phosphorylation were evaluated. The formation of Mineralized Tissue in SrRn-treated pulp Tissue in rat upper first molars was evaluated histologically. The SrRn up-regulated cell proliferation and expression of Alp (alkaline phosphatase), Bsp (bone sialoprotein), Dmp (dentin matrix acidic phosphoprotein)-1, Dspp (dentin sialophosphoprotein), and Oc (osteocalcin) in a dose-dependent manner. Mineralized nodule formation was also enhanced by SrRn. NPS-2143, a calcium-sensing receptor (CaSR) antagonist, and siRNA against the CaSR gene blocked SrRn-induced proliferation, odonto-/osteoblastic gene expression, and Mineralized nodule formation. SrRn induced Akt phosphorylation, and this was blocked by NPS-2143. Topical application of SrRn to exposed rat molar pulps induced the formation of osteodentin-like Mineralized Tissue. Our study revealed for the first time that SrRn promotes proliferation and odonto-/osteogenic differentiation/mineralization of MDPs via PI3K/Akt signaling activated by CaSR in vitro; Mineralized Tissue forms from the dental pulp in vivo.
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Strontium ranelate promotes odonto-/osteogenic differentiation/mineralization of dental papillae cells in vitro and Mineralized Tissue formation of the dental pulp in vivo
Scientific Reports, 2018Co-Authors: Alamuddin Bakhit, Nobuyuki Kawashima, Kentaro Hashimoto, Sonoko Noda, Keisuke Nara, Masashi Kuramoto, Kento Tazawa, Takashi OkijiAbstract:This study examined the effects and mechanisms of strontium ranelate (SrRn)—a drug used to treat osteoporosis—on the proliferation and differentiation/mineralization of cloned dental pulp-like cells (mouse dental papillae cells; MDPs). It also determined whether topical application of SrRn to exposed dental pulp Tissue promotes the formation of Mineralized Tissue in vivo. The MDPs were cultured with or without SrRn, and cell proliferation, odonto-/osteoblastic gene expression, Mineralized nodule formation, and Akt phosphorylation were evaluated. The formation of Mineralized Tissue in SrRn-treated pulp Tissue in rat upper first molars was evaluated histologically. The SrRn up-regulated cell proliferation and expression of Alp (alkaline phosphatase), Bsp (bone sialoprotein), Dmp (dentin matrix acidic phosphoprotein)-1, Dspp (dentin sialophosphoprotein), and Oc (osteocalcin) in a dose-dependent manner. Mineralized nodule formation was also enhanced by SrRn. NPS-2143, a calcium-sensing receptor (CaSR) antagonist, and siRNA against the CaSR gene blocked SrRn-induced proliferation, odonto-/osteoblastic gene expression, and Mineralized nodule formation. SrRn induced Akt phosphorylation, and this was blocked by NPS-2143. Topical application of SrRn to exposed rat molar pulps induced the formation of osteodentin-like Mineralized Tissue. Our study revealed for the first time that SrRn promotes proliferation and odonto-/osteogenic differentiation/mineralization of MDPs via PI3K/Akt signaling activated by CaSR in vitro; Mineralized Tissue forms from the dental pulp in vivo.