The Experts below are selected from a list of 139662 Experts worldwide ranked by ideXlab platform
Teruo Okano - One of the best experts on this subject based on the ideXlab platform.
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MHS - ECM-mimicking thermoresponsive Surface for manipulating hepatocyte sheets with maintenance of hepatic functions
2016 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2016Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatic cellular sheet-based tissue engineering is an attractive method for the treatment of liver diseases. However, Cultured hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. For providing extracellular matrix (ECM)-mimicking micro-environment to the isolated hepatocytes, poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface was functionalized with heparin, which has a similar structure to heparan sulfate on proteoglycans and possesses an affinity interaction with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF). A cell cultivation system using HB-EGF bound heparin-immobilized thermoresponsive cell Culture Surface maintains the survival and adhesion of hepatocytes with highly hepatic functions such as albumin secretion. Bound HB-EGF stimulated EGF receptor and MAPK family ERK1/2 in dose-dependent manner. Time-course of HB-EGF stimulation revealed that the internalization of EGF receptors on heparin-immobilized Surface was partially suppressed during a few days incubation. Sustained stimulation and activation of Cultured hepatocytes on the HB-EGF bound Surfaces were also confirmed. In addition, both the Cultured hepatocytes and the growth factors detached as a contiguous cell sheet from the Surface, accompanied by swelling and expanding of grafted thermoresponsive polymer. In conclusion, ECM-mimicking thermoresponsive cell Culture Surfaces facilitated the manipulation of hepatic cell sheets with maintaining hepatic functions by changing temperature. Creation of transferable and functional liver tissues is considered to have a potential to treat liver disease.
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MHS - Fabrication of functional liver tissues by cell sheet-based bioassembler technologies
2015 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2015Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatocyte-based tissue engineering is an attractive method for the treatment of liver diseases. However, hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. To overcome these problems, our laboratory has designed new types of thermoresponsive cell Culture Surfaces for advancing the next stage of cell sheet-based tissue engineering. One approach is to resemble the microstructures of native tissues and organs. Most in vivo tissues and organs have their own unique structures, such as multi-cellular, micrometer-scale organizations. Micropatterned thermoresponsive Surfaces were designed to enable both the culturing and recovery of patterned heterotypic cell sheets. Another approach is to use extracellular matrices (ECMs), which resemble the surrounding environments of in vivo native tissues. Heparin-functionalized poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface, which interacts with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF), has been designed for maintaining hepatic functions during the cultivation. The function of hepatic cell sheet was maintained by using these new types of thermoresponsive cell Culture Surfaces.
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Recent development of temperature-responsive Surfaces and their application for cell sheet engineering
Regenerative biomaterials, 2014Co-Authors: Zhonglan Tang, Teruo OkanoAbstract:Cell sheet engineering, which fabricates sheet-like tissues without biodegradable scaffolds, has been proposed as a novel approach for tissue engineering. Cells have been Cultured and proliferate to confluence on a temperature-responsive cell Culture Surface at 37°C. By decreasing temperature to 20°C, an intact cell sheet can be harvested from the Culture Surface without enzymatic treatment. This new approach enables cells to keep their cell-cell junction, cell Surface proteins and extracellular matrix. Therefore, recovered cell sheet can be easily not only transplanted to host tissue, but also constructed a three-dimensional (3D) tissue by layering cell sheets. Moreover, cell sheet manipulation technology and bioreactor have been combined with the cell sheet technology to fabricate a complex and functional 3D tissue in vitro. So far, cell sheet technology has been applied in regenerative medicine for several tissues, and a number of clinical studies have been performed. In this review, recent advances in the preparation of temperature-responsive cell Culture Surface, the fabrication of organ-like tissue and the clinical application of cell sheet engineering are summarized and discussed.
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Recent Development of Temperature-Responsive Cell Culture Surface Using Poly(N-isopropylacrylamide)
Journal of Polymer Science Part B: Polymer Physics, 2014Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Teruo OkanoAbstract:Poly(N-isopropylacrylamide) (PIPAAm), which is a well-known temperature-responsive polymer, is modified on substrates by various methods. At 37 C, PIPAAm modified Surface is hydrophobic and allows cells to adhere to and prolif- erate on the Surface. By reducing temperature below the lower critical solution temperature of PIPAAm, the Surface turns to hydrophilic and allows cells to detach themselves from the sur- face spontaneously. With this technology, cell sheet engineer- ing is established several years ago. This review focuses on the preparations and characteristics of PIPAAm-modified surfa- ces, and discusses the effect of Surface properties on cell adhe- sion and deadhesion. In addition, the recent improvement of PIPAAm-modified Surfaces for cell Culture and the clinical applications of cell sheets harvested from the Surfaces are also mentioned. V C 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 917-926
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Accelerated cell-sheet recovery from a Surface successively grafted with polyacrylamide and poly(N-isopropylacrylamide).
Acta biomaterialia, 2014Co-Authors: Yoshikatsu Akiyama, Masayuki Yamato, Akihiko Kikuchi, Teruo OkanoAbstract:A double polymeric nanolayer consisting of poly(N-isopropylacrylamide) (PIPAAm) and hydrophilic polyacrylamide (PAAm) was deposited on tissue Culture polystyrene (TCPS) Surfaces using electron beam irradiation to form a new temperature-responsive cell Culture Surface in which the basal hydrophilic PAAm component in the double polymeric layer promotes the hydration of the upper PIPAAm layer and induces rapid cell detachment compared to a conventional temperature-responsive cell Culture Surface, PIPAAm-grafted TCPS (PIPAAm-TCPS). Take-off angle-dependent X-ray photoelectron spectroscopy spectral analysis demonstrated that the grafted PIPAAm and PAAm components were located in the upper and basal regions of the double polymeric layer, respectively, suggesting that the double polymeric layer forms an inter-penetrating-network-like structure with PAAm at the basal portion of the PIPAAm grafted chains. The wettability of the temperature-responsive cell Culture Surfaces with the double polymeric layer tended to be more hydrophilic, with an increase in the basal PAAm graft density at a constant PIPAAm graft density. However, when the graft densities of the upper PIPAAm and basal PAAm were optimized, the resulting temperature-responsive cell Culture Surface with the double polymeric layer exhibited rapid cell detachment while maintaining cell adhesive character comparable to that of PIPAAm-TCPS. The cell adhesive character was altered from cell-adhesive to cell-repellent with increasing PAAm or PIPAAm graft density. The cell adhesive character of the temperature-responsive cell Culture Surfaces was relatively consistent with their contact angles. These results strongly suggest that the basal PAAm Surface properties affect the degree of hydration and dehydration of the subsequently grafted PIPAAm. In addition, the roles of the hydrophilic component in accelerating cell detachment are further discussed in terms of the mobility of the grafted PIPAAm chains. Applications of this insight might be useful for designing temperature-responsive cell Culture Surfaces for achieving efficient cell Culture and quick target cell detachment.
Masayuki Yamato - One of the best experts on this subject based on the ideXlab platform.
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MHS - ECM-mimicking thermoresponsive Surface for manipulating hepatocyte sheets with maintenance of hepatic functions
2016 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2016Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatic cellular sheet-based tissue engineering is an attractive method for the treatment of liver diseases. However, Cultured hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. For providing extracellular matrix (ECM)-mimicking micro-environment to the isolated hepatocytes, poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface was functionalized with heparin, which has a similar structure to heparan sulfate on proteoglycans and possesses an affinity interaction with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF). A cell cultivation system using HB-EGF bound heparin-immobilized thermoresponsive cell Culture Surface maintains the survival and adhesion of hepatocytes with highly hepatic functions such as albumin secretion. Bound HB-EGF stimulated EGF receptor and MAPK family ERK1/2 in dose-dependent manner. Time-course of HB-EGF stimulation revealed that the internalization of EGF receptors on heparin-immobilized Surface was partially suppressed during a few days incubation. Sustained stimulation and activation of Cultured hepatocytes on the HB-EGF bound Surfaces were also confirmed. In addition, both the Cultured hepatocytes and the growth factors detached as a contiguous cell sheet from the Surface, accompanied by swelling and expanding of grafted thermoresponsive polymer. In conclusion, ECM-mimicking thermoresponsive cell Culture Surfaces facilitated the manipulation of hepatic cell sheets with maintaining hepatic functions by changing temperature. Creation of transferable and functional liver tissues is considered to have a potential to treat liver disease.
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MHS - Fabrication of functional liver tissues by cell sheet-based bioassembler technologies
2015 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2015Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatocyte-based tissue engineering is an attractive method for the treatment of liver diseases. However, hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. To overcome these problems, our laboratory has designed new types of thermoresponsive cell Culture Surfaces for advancing the next stage of cell sheet-based tissue engineering. One approach is to resemble the microstructures of native tissues and organs. Most in vivo tissues and organs have their own unique structures, such as multi-cellular, micrometer-scale organizations. Micropatterned thermoresponsive Surfaces were designed to enable both the culturing and recovery of patterned heterotypic cell sheets. Another approach is to use extracellular matrices (ECMs), which resemble the surrounding environments of in vivo native tissues. Heparin-functionalized poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface, which interacts with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF), has been designed for maintaining hepatic functions during the cultivation. The function of hepatic cell sheet was maintained by using these new types of thermoresponsive cell Culture Surfaces.
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Accelerated cell-sheet recovery from a Surface successively grafted with polyacrylamide and poly(N-isopropylacrylamide).
Acta biomaterialia, 2014Co-Authors: Yoshikatsu Akiyama, Masayuki Yamato, Akihiko Kikuchi, Teruo OkanoAbstract:A double polymeric nanolayer consisting of poly(N-isopropylacrylamide) (PIPAAm) and hydrophilic polyacrylamide (PAAm) was deposited on tissue Culture polystyrene (TCPS) Surfaces using electron beam irradiation to form a new temperature-responsive cell Culture Surface in which the basal hydrophilic PAAm component in the double polymeric layer promotes the hydration of the upper PIPAAm layer and induces rapid cell detachment compared to a conventional temperature-responsive cell Culture Surface, PIPAAm-grafted TCPS (PIPAAm-TCPS). Take-off angle-dependent X-ray photoelectron spectroscopy spectral analysis demonstrated that the grafted PIPAAm and PAAm components were located in the upper and basal regions of the double polymeric layer, respectively, suggesting that the double polymeric layer forms an inter-penetrating-network-like structure with PAAm at the basal portion of the PIPAAm grafted chains. The wettability of the temperature-responsive cell Culture Surfaces with the double polymeric layer tended to be more hydrophilic, with an increase in the basal PAAm graft density at a constant PIPAAm graft density. However, when the graft densities of the upper PIPAAm and basal PAAm were optimized, the resulting temperature-responsive cell Culture Surface with the double polymeric layer exhibited rapid cell detachment while maintaining cell adhesive character comparable to that of PIPAAm-TCPS. The cell adhesive character was altered from cell-adhesive to cell-repellent with increasing PAAm or PIPAAm graft density. The cell adhesive character of the temperature-responsive cell Culture Surfaces was relatively consistent with their contact angles. These results strongly suggest that the basal PAAm Surface properties affect the degree of hydration and dehydration of the subsequently grafted PIPAAm. In addition, the roles of the hydrophilic component in accelerating cell detachment are further discussed in terms of the mobility of the grafted PIPAAm chains. Applications of this insight might be useful for designing temperature-responsive cell Culture Surfaces for achieving efficient cell Culture and quick target cell detachment.
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Preparation of Poly(N-isopropylacrylamide) Grafted Polydimethylsiloxane by Using Electron Beam Irradiation
Journal of Robotics and Mechatronics, 2013Co-Authors: Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:A poly(N-isopropylacrylamide) (PIPAAm) grafted poly(dimethylsiloxane) (PDMS) Surface was prepared as a temperature-responsive cell Culture Surface by using electron beam (EB) irradiation. Different chemical treatments to modify the bare PDMS Surface were investigated for subsequent grafting of PIPAAm, and treatment conditions were optimized to prepare the temperature-responsive cell Culture Surface. The PDMS Surface was initially activated to form silanol groups with conventional O2 plasma or hydrochloric acid (HCl) treatment. Activated PDMS Surfaces were individually immobilized with three different conventional silane compounds, i.e., 3-mercaptopropyltrimethoxysilane (MerTMS), 3-methacryloxypropyltrimethoxysilane (MetTMS), and 3-aminopropyltrimethoxysilane (AmiTMS). O2 plasma treatment made PDMS more hydrophilic. In contrast, PDMS Surfaces activated with HCl treatment were relatively hydrophobic. Observation of the activated PDMS Surface modified with MerTMS, MetTMS, and AmiTMS indicated that these silane compounds had been favorably immobilized on plasma-treated PDMS Surfaces. FT-IR/ATR analysis demonstrated that immobilized silane compounds enabled PIPAAm grafting on the PDMS Surface. Cell attachment and detachment analysis also suggested that the PDMS Surface sequentially treated with O2 plasma and AmiTMS compound was a substrate appropriate for preparing a temperature-responsive cell Culture Surface by EB irradiation-induced PIPAAm grafting method. The intelligent Surface may further be applied to mechanically stretchable temperature-responsive cell Culture Surfaces.
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Heparin-functionalized thermoresponsive Surface: a versatile cell Culture substrate for regulating multivalent affinity binding with heparin-binding proteins by temperature changes.
Organogenesis, 2013Co-Authors: Yoshinori Arisaka, Yoshikatsu Akiyama, Jun Kobayashi, Masayuki Yamato, Teruo OkanoAbstract:Temperature-dependent regulation of affinity binding between bioactive ligands and their cell membrane receptors is an attractive approach for the dynamic control of cellular adhesion, proliferation, migration, differentiation, and signal transduction. Covalent conjugation of bioactive ligands onto thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-grafted Surfaces facilitates the modulation of one-on-one affinity binding between bioactive ligands and cellular receptors by changing temperature. For the dynamic control of the multivalent affinity binding between heparin and heparin-binding proteins, thermoresponsive cell Culture Surface modified with heparin, which interacts with heparin-binding proteins such as basic fibroblast growth factor (bFGF), has been proposed. Heparin-functionalized thermoresponsive cell Culture Surface induces (1) the multivalent affinity binding of bFGF in active form and (2) accelerating cell sheet formation in the state of shrunken PIPAAm chains at 37°C. By lowering temperature to 20°C, the affinity binding between bFGF and immobilized heparin is reduced with increasing the mobility of heparin and the swollen PIPAAm chains, leading to the detachment of Cultured cells. Therefore, heparin-functionalized thermoresponsive cell Culture Surface was able to enhance cell proliferation and detach confluent cells as a contiguous cell sheet by changing temperature. A cell cultivation system using heparin-functionalized thermoresponsive cell Culture Surface is versatile for immobilizing other heparin-binding proteins such as vascular endothelial growth factor, fibronectin, antithrombin III, and hepatocyte growth factor, etc. for tuning the adhesion, growth, and differentiation of various cell species.
Yoshikatsu Akiyama - One of the best experts on this subject based on the ideXlab platform.
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MHS - ECM-mimicking thermoresponsive Surface for manipulating hepatocyte sheets with maintenance of hepatic functions
2016 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2016Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatic cellular sheet-based tissue engineering is an attractive method for the treatment of liver diseases. However, Cultured hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. For providing extracellular matrix (ECM)-mimicking micro-environment to the isolated hepatocytes, poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface was functionalized with heparin, which has a similar structure to heparan sulfate on proteoglycans and possesses an affinity interaction with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF). A cell cultivation system using HB-EGF bound heparin-immobilized thermoresponsive cell Culture Surface maintains the survival and adhesion of hepatocytes with highly hepatic functions such as albumin secretion. Bound HB-EGF stimulated EGF receptor and MAPK family ERK1/2 in dose-dependent manner. Time-course of HB-EGF stimulation revealed that the internalization of EGF receptors on heparin-immobilized Surface was partially suppressed during a few days incubation. Sustained stimulation and activation of Cultured hepatocytes on the HB-EGF bound Surfaces were also confirmed. In addition, both the Cultured hepatocytes and the growth factors detached as a contiguous cell sheet from the Surface, accompanied by swelling and expanding of grafted thermoresponsive polymer. In conclusion, ECM-mimicking thermoresponsive cell Culture Surfaces facilitated the manipulation of hepatic cell sheets with maintaining hepatic functions by changing temperature. Creation of transferable and functional liver tissues is considered to have a potential to treat liver disease.
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MHS - Fabrication of functional liver tissues by cell sheet-based bioassembler technologies
2015 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2015Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatocyte-based tissue engineering is an attractive method for the treatment of liver diseases. However, hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. To overcome these problems, our laboratory has designed new types of thermoresponsive cell Culture Surfaces for advancing the next stage of cell sheet-based tissue engineering. One approach is to resemble the microstructures of native tissues and organs. Most in vivo tissues and organs have their own unique structures, such as multi-cellular, micrometer-scale organizations. Micropatterned thermoresponsive Surfaces were designed to enable both the culturing and recovery of patterned heterotypic cell sheets. Another approach is to use extracellular matrices (ECMs), which resemble the surrounding environments of in vivo native tissues. Heparin-functionalized poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface, which interacts with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF), has been designed for maintaining hepatic functions during the cultivation. The function of hepatic cell sheet was maintained by using these new types of thermoresponsive cell Culture Surfaces.
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Recent Development of Temperature-Responsive Cell Culture Surface Using Poly(N-isopropylacrylamide)
Journal of Polymer Science Part B: Polymer Physics, 2014Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Teruo OkanoAbstract:Poly(N-isopropylacrylamide) (PIPAAm), which is a well-known temperature-responsive polymer, is modified on substrates by various methods. At 37 C, PIPAAm modified Surface is hydrophobic and allows cells to adhere to and prolif- erate on the Surface. By reducing temperature below the lower critical solution temperature of PIPAAm, the Surface turns to hydrophilic and allows cells to detach themselves from the sur- face spontaneously. With this technology, cell sheet engineer- ing is established several years ago. This review focuses on the preparations and characteristics of PIPAAm-modified surfa- ces, and discusses the effect of Surface properties on cell adhe- sion and deadhesion. In addition, the recent improvement of PIPAAm-modified Surfaces for cell Culture and the clinical applications of cell sheets harvested from the Surfaces are also mentioned. V C 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 917-926
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Accelerated cell-sheet recovery from a Surface successively grafted with polyacrylamide and poly(N-isopropylacrylamide).
Acta biomaterialia, 2014Co-Authors: Yoshikatsu Akiyama, Masayuki Yamato, Akihiko Kikuchi, Teruo OkanoAbstract:A double polymeric nanolayer consisting of poly(N-isopropylacrylamide) (PIPAAm) and hydrophilic polyacrylamide (PAAm) was deposited on tissue Culture polystyrene (TCPS) Surfaces using electron beam irradiation to form a new temperature-responsive cell Culture Surface in which the basal hydrophilic PAAm component in the double polymeric layer promotes the hydration of the upper PIPAAm layer and induces rapid cell detachment compared to a conventional temperature-responsive cell Culture Surface, PIPAAm-grafted TCPS (PIPAAm-TCPS). Take-off angle-dependent X-ray photoelectron spectroscopy spectral analysis demonstrated that the grafted PIPAAm and PAAm components were located in the upper and basal regions of the double polymeric layer, respectively, suggesting that the double polymeric layer forms an inter-penetrating-network-like structure with PAAm at the basal portion of the PIPAAm grafted chains. The wettability of the temperature-responsive cell Culture Surfaces with the double polymeric layer tended to be more hydrophilic, with an increase in the basal PAAm graft density at a constant PIPAAm graft density. However, when the graft densities of the upper PIPAAm and basal PAAm were optimized, the resulting temperature-responsive cell Culture Surface with the double polymeric layer exhibited rapid cell detachment while maintaining cell adhesive character comparable to that of PIPAAm-TCPS. The cell adhesive character was altered from cell-adhesive to cell-repellent with increasing PAAm or PIPAAm graft density. The cell adhesive character of the temperature-responsive cell Culture Surfaces was relatively consistent with their contact angles. These results strongly suggest that the basal PAAm Surface properties affect the degree of hydration and dehydration of the subsequently grafted PIPAAm. In addition, the roles of the hydrophilic component in accelerating cell detachment are further discussed in terms of the mobility of the grafted PIPAAm chains. Applications of this insight might be useful for designing temperature-responsive cell Culture Surfaces for achieving efficient cell Culture and quick target cell detachment.
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Preparation of Poly(N-isopropylacrylamide) Grafted Polydimethylsiloxane by Using Electron Beam Irradiation
Journal of Robotics and Mechatronics, 2013Co-Authors: Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:A poly(N-isopropylacrylamide) (PIPAAm) grafted poly(dimethylsiloxane) (PDMS) Surface was prepared as a temperature-responsive cell Culture Surface by using electron beam (EB) irradiation. Different chemical treatments to modify the bare PDMS Surface were investigated for subsequent grafting of PIPAAm, and treatment conditions were optimized to prepare the temperature-responsive cell Culture Surface. The PDMS Surface was initially activated to form silanol groups with conventional O2 plasma or hydrochloric acid (HCl) treatment. Activated PDMS Surfaces were individually immobilized with three different conventional silane compounds, i.e., 3-mercaptopropyltrimethoxysilane (MerTMS), 3-methacryloxypropyltrimethoxysilane (MetTMS), and 3-aminopropyltrimethoxysilane (AmiTMS). O2 plasma treatment made PDMS more hydrophilic. In contrast, PDMS Surfaces activated with HCl treatment were relatively hydrophobic. Observation of the activated PDMS Surface modified with MerTMS, MetTMS, and AmiTMS indicated that these silane compounds had been favorably immobilized on plasma-treated PDMS Surfaces. FT-IR/ATR analysis demonstrated that immobilized silane compounds enabled PIPAAm grafting on the PDMS Surface. Cell attachment and detachment analysis also suggested that the PDMS Surface sequentially treated with O2 plasma and AmiTMS compound was a substrate appropriate for preparing a temperature-responsive cell Culture Surface by EB irradiation-induced PIPAAm grafting method. The intelligent Surface may further be applied to mechanically stretchable temperature-responsive cell Culture Surfaces.
Zhonglan Tang - One of the best experts on this subject based on the ideXlab platform.
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Recent development of temperature-responsive Surfaces and their application for cell sheet engineering
Regenerative biomaterials, 2014Co-Authors: Zhonglan Tang, Teruo OkanoAbstract:Cell sheet engineering, which fabricates sheet-like tissues without biodegradable scaffolds, has been proposed as a novel approach for tissue engineering. Cells have been Cultured and proliferate to confluence on a temperature-responsive cell Culture Surface at 37°C. By decreasing temperature to 20°C, an intact cell sheet can be harvested from the Culture Surface without enzymatic treatment. This new approach enables cells to keep their cell-cell junction, cell Surface proteins and extracellular matrix. Therefore, recovered cell sheet can be easily not only transplanted to host tissue, but also constructed a three-dimensional (3D) tissue by layering cell sheets. Moreover, cell sheet manipulation technology and bioreactor have been combined with the cell sheet technology to fabricate a complex and functional 3D tissue in vitro. So far, cell sheet technology has been applied in regenerative medicine for several tissues, and a number of clinical studies have been performed. In this review, recent advances in the preparation of temperature-responsive cell Culture Surface, the fabrication of organ-like tissue and the clinical application of cell sheet engineering are summarized and discussed.
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Recent Development of Temperature-Responsive Cell Culture Surface Using Poly(N-isopropylacrylamide)
Journal of Polymer Science Part B: Polymer Physics, 2014Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Teruo OkanoAbstract:Poly(N-isopropylacrylamide) (PIPAAm), which is a well-known temperature-responsive polymer, is modified on substrates by various methods. At 37 C, PIPAAm modified Surface is hydrophobic and allows cells to adhere to and prolif- erate on the Surface. By reducing temperature below the lower critical solution temperature of PIPAAm, the Surface turns to hydrophilic and allows cells to detach themselves from the sur- face spontaneously. With this technology, cell sheet engineer- ing is established several years ago. This review focuses on the preparations and characteristics of PIPAAm-modified surfa- ces, and discusses the effect of Surface properties on cell adhe- sion and deadhesion. In addition, the recent improvement of PIPAAm-modified Surfaces for cell Culture and the clinical applications of cell sheets harvested from the Surfaces are also mentioned. V C 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 917-926
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Shear stress-dependent cell detachment from temperature-responsive cell Culture Surfaces in a microfluidic device.
Biomaterials, 2012Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Kazuyoshi Itoga, Jun Kobayashi, Masayuki Yamato, Teruo OkanoAbstract:Abstract A new approach to quantitatively estimate the interaction between cells and material has been proposed by using a microfluidic system, which was made of poly(dimethylsiloxane) (PDMS) chip bonding on a temperature-responsive cell Culture Surface consisted of poly( N -isopropylacrylamide) (PIPAAm) grafted tissue Culture polystyrene (TCPS) (PIPAAm-TCPS) having five parallel test channels for cell Culture. This construction allows concurrently generating five different shear forces to apply to cells in individual microchannels having various resistance of each channel and simultaneously gives an identical cell incubation condition to all test channels. NIH/3T3 mouse fibroblast cells (MFCs) and bovine aortic endothelial cells (BAECs) were well adhered and spread on all channels of PIPAAm-TCPS at 37 °C. In our previous study, reducing Culture temperature below the lower critical solution temperature (LCST) of PIPAAm (32 °C), cells detach themselves from hydrated PIPAAm grafted Surfaces spontaneously. In this study, cell detachment process from hydrated PIPAAm-TCPS was promoted by shear forces applied to cells in microchannels. Shear stress-dependent cell detachment process from PIPAAm-TCPS was evaluated at various shear stresses. Either MFCs or BAECs in the microchannel with the strongest shear stress were found to be detached from the substrate more quickly than those in other microchannels. A cell transformation rate constant C t and an intrinsic cell detachment rate constant k 0 were obtained through studying the effect of shear stress on cell detachment with a peeling model. The proposed device and quantitative analysis could be used to assess the possible interaction between cells and PIPAAm layer with a potential application to design a cell sheet Culture Surface for tissue engineering.
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MHS - Fabrication of microfluidic device on temperature-responsive cell Culture Surface for studying the shear stress-dependent cell detachment
2011 International Symposium on Micro-NanoMechatronics and Human Science, 2011Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Kazuyoshi Itoga, Jun Kobayashi, Teruo OkanoAbstract:We proposed a novel approach to quantitatively estimate the strength of cell-material interaction by using microfluidic system. The microfluidic device was made of poly (dimethylsiloxane) chip bonding on the temperature-responsive cell Culture Surface consisted of poly(N-isopropylacrylamide) (PIPAAm) grafted tissue Culture polystyrene (TCPS) (PIPAAm-TCPS), containing five parallel test channels for cell Culture. This construction allows concurrent generating five different shear forces applied to cells in each microchannel by varying the resistance of each channel, as well as obtaining identical cell incubation in each test channel. Bovine aortic endothelial cells were well adhered and spread on PIPAAm-TCPS in each channel at cell Culture temperature of 37°C. Reducing temperature below the lower critical solution temperature of PIPAAm and starting flow, cells were peeled off from the hydrophilic PIPAAm-TCPS by the shear forces generated by flow. Shear stress dependent cell detachment process was evaluated with the different shear stress. Critical shear stress for cell detachment was achieved through studying the effect of shear stress on cell detachment times. As a result, the bonding strength between cells and hydrated PIPAAm-TCPS was weaker than that in other cell bonding biomaterials.
Jun Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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MHS - ECM-mimicking thermoresponsive Surface for manipulating hepatocyte sheets with maintenance of hepatic functions
2016 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2016Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatic cellular sheet-based tissue engineering is an attractive method for the treatment of liver diseases. However, Cultured hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. For providing extracellular matrix (ECM)-mimicking micro-environment to the isolated hepatocytes, poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface was functionalized with heparin, which has a similar structure to heparan sulfate on proteoglycans and possesses an affinity interaction with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF). A cell cultivation system using HB-EGF bound heparin-immobilized thermoresponsive cell Culture Surface maintains the survival and adhesion of hepatocytes with highly hepatic functions such as albumin secretion. Bound HB-EGF stimulated EGF receptor and MAPK family ERK1/2 in dose-dependent manner. Time-course of HB-EGF stimulation revealed that the internalization of EGF receptors on heparin-immobilized Surface was partially suppressed during a few days incubation. Sustained stimulation and activation of Cultured hepatocytes on the HB-EGF bound Surfaces were also confirmed. In addition, both the Cultured hepatocytes and the growth factors detached as a contiguous cell sheet from the Surface, accompanied by swelling and expanding of grafted thermoresponsive polymer. In conclusion, ECM-mimicking thermoresponsive cell Culture Surfaces facilitated the manipulation of hepatic cell sheets with maintaining hepatic functions by changing temperature. Creation of transferable and functional liver tissues is considered to have a potential to treat liver disease.
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MHS - Fabrication of functional liver tissues by cell sheet-based bioassembler technologies
2015 International Symposium on Micro-NanoMechatronics and Human Science (MHS), 2015Co-Authors: Jun Kobayashi, Yoshikatsu Akiyama, Masayuki Yamato, Teruo OkanoAbstract:Hepatocyte-based tissue engineering is an attractive method for the treatment of liver diseases. However, hepatocytes rapidly lose their viability and phenotypic functions on isolation from the native in vivo microenvironment of the liver. To overcome these problems, our laboratory has designed new types of thermoresponsive cell Culture Surfaces for advancing the next stage of cell sheet-based tissue engineering. One approach is to resemble the microstructures of native tissues and organs. Most in vivo tissues and organs have their own unique structures, such as multi-cellular, micrometer-scale organizations. Micropatterned thermoresponsive Surfaces were designed to enable both the culturing and recovery of patterned heterotypic cell sheets. Another approach is to use extracellular matrices (ECMs), which resemble the surrounding environments of in vivo native tissues. Heparin-functionalized poly(N-isopropylacrylamide) (PIPAAm)-grafted cell Culture Surface, which interacts with heparin-binding proteins such as heparin-binding EGF-like growth factor (HB-EGF), has been designed for maintaining hepatic functions during the cultivation. The function of hepatic cell sheet was maintained by using these new types of thermoresponsive cell Culture Surfaces.
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Heparin-functionalized thermoresponsive Surface: a versatile cell Culture substrate for regulating multivalent affinity binding with heparin-binding proteins by temperature changes.
Organogenesis, 2013Co-Authors: Yoshinori Arisaka, Yoshikatsu Akiyama, Jun Kobayashi, Masayuki Yamato, Teruo OkanoAbstract:Temperature-dependent regulation of affinity binding between bioactive ligands and their cell membrane receptors is an attractive approach for the dynamic control of cellular adhesion, proliferation, migration, differentiation, and signal transduction. Covalent conjugation of bioactive ligands onto thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-grafted Surfaces facilitates the modulation of one-on-one affinity binding between bioactive ligands and cellular receptors by changing temperature. For the dynamic control of the multivalent affinity binding between heparin and heparin-binding proteins, thermoresponsive cell Culture Surface modified with heparin, which interacts with heparin-binding proteins such as basic fibroblast growth factor (bFGF), has been proposed. Heparin-functionalized thermoresponsive cell Culture Surface induces (1) the multivalent affinity binding of bFGF in active form and (2) accelerating cell sheet formation in the state of shrunken PIPAAm chains at 37°C. By lowering temperature to 20°C, the affinity binding between bFGF and immobilized heparin is reduced with increasing the mobility of heparin and the swollen PIPAAm chains, leading to the detachment of Cultured cells. Therefore, heparin-functionalized thermoresponsive cell Culture Surface was able to enhance cell proliferation and detach confluent cells as a contiguous cell sheet by changing temperature. A cell cultivation system using heparin-functionalized thermoresponsive cell Culture Surface is versatile for immobilizing other heparin-binding proteins such as vascular endothelial growth factor, fibronectin, antithrombin III, and hepatocyte growth factor, etc. for tuning the adhesion, growth, and differentiation of various cell species.
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Shear stress-dependent cell detachment from temperature-responsive cell Culture Surfaces in a microfluidic device.
Biomaterials, 2012Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Kazuyoshi Itoga, Jun Kobayashi, Masayuki Yamato, Teruo OkanoAbstract:Abstract A new approach to quantitatively estimate the interaction between cells and material has been proposed by using a microfluidic system, which was made of poly(dimethylsiloxane) (PDMS) chip bonding on a temperature-responsive cell Culture Surface consisted of poly( N -isopropylacrylamide) (PIPAAm) grafted tissue Culture polystyrene (TCPS) (PIPAAm-TCPS) having five parallel test channels for cell Culture. This construction allows concurrently generating five different shear forces to apply to cells in individual microchannels having various resistance of each channel and simultaneously gives an identical cell incubation condition to all test channels. NIH/3T3 mouse fibroblast cells (MFCs) and bovine aortic endothelial cells (BAECs) were well adhered and spread on all channels of PIPAAm-TCPS at 37 °C. In our previous study, reducing Culture temperature below the lower critical solution temperature (LCST) of PIPAAm (32 °C), cells detach themselves from hydrated PIPAAm grafted Surfaces spontaneously. In this study, cell detachment process from hydrated PIPAAm-TCPS was promoted by shear forces applied to cells in microchannels. Shear stress-dependent cell detachment process from PIPAAm-TCPS was evaluated at various shear stresses. Either MFCs or BAECs in the microchannel with the strongest shear stress were found to be detached from the substrate more quickly than those in other microchannels. A cell transformation rate constant C t and an intrinsic cell detachment rate constant k 0 were obtained through studying the effect of shear stress on cell detachment with a peeling model. The proposed device and quantitative analysis could be used to assess the possible interaction between cells and PIPAAm layer with a potential application to design a cell sheet Culture Surface for tissue engineering.
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MHS - Fabrication of microfluidic device on temperature-responsive cell Culture Surface for studying the shear stress-dependent cell detachment
2011 International Symposium on Micro-NanoMechatronics and Human Science, 2011Co-Authors: Zhonglan Tang, Yoshikatsu Akiyama, Kazuyoshi Itoga, Jun Kobayashi, Teruo OkanoAbstract:We proposed a novel approach to quantitatively estimate the strength of cell-material interaction by using microfluidic system. The microfluidic device was made of poly (dimethylsiloxane) chip bonding on the temperature-responsive cell Culture Surface consisted of poly(N-isopropylacrylamide) (PIPAAm) grafted tissue Culture polystyrene (TCPS) (PIPAAm-TCPS), containing five parallel test channels for cell Culture. This construction allows concurrent generating five different shear forces applied to cells in each microchannel by varying the resistance of each channel, as well as obtaining identical cell incubation in each test channel. Bovine aortic endothelial cells were well adhered and spread on PIPAAm-TCPS in each channel at cell Culture temperature of 37°C. Reducing temperature below the lower critical solution temperature of PIPAAm and starting flow, cells were peeled off from the hydrophilic PIPAAm-TCPS by the shear forces generated by flow. Shear stress dependent cell detachment process was evaluated with the different shear stress. Critical shear stress for cell detachment was achieved through studying the effect of shear stress on cell detachment times. As a result, the bonding strength between cells and hydrated PIPAAm-TCPS was weaker than that in other cell bonding biomaterials.
