ORCID Profile
0000-0001-6753-3678
Current Organisations
University of Tsukuba
,
National Institute for Materials Science
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Publisher: American Chemical Society (ACS)
Date: 12-04-2011
DOI: 10.1021/LA200487W
Abstract: Micropatterned surfaces are very useful to control cell microenvironment and investigate the physical effects on cell function. In this study, poly(vinyl alcohol) (PVA) micropatterns on polystyrene cell-culture plates were prepared using UV photolithography. Cell adhesive polystyrene geometries of triangle, square, pentagon, hexagon, and circle were surrounded by cell nonadhesive PVA to manipulate cell shapes. These different geometries had the same small surface areas for cell spreading. Human mesenchymal stem cells (MSCs) were cultured on the micropatterned surface, and the effect of cell geometry on adipogenic differentiation was investigated. MSCs adhered to the geometric micropatterns and formed arrays of single cell with different shapes. The distribution patterns of actin filaments were similar among these cell shapes and remolded during adipogenesis. The adipogenic differentiation potential of MSCs was similar on the small size triangular, square, pentagonal, hexagonal, and circular geometries according to lipid vacuoles staining. This simple micropatterning technique using photoreactive molecules will be useful for creating micropatterns of arbitrary design on an organic surface, and cell functions can be directly and systematically compared on a single surface without external factors resulting from separate cell culture and coating method.
Publisher: Wiley
Date: 22-06-2012
Abstract: Porous collagen scaffolds with micropatterned structures are manufactured using preformed ice micropattern templates. The scaffolds show precisely controlled pore structures and micropattern structures of bioactive substances, which can be tethered by designing a program.
Publisher: Informa UK Limited
Date: 2009
Publisher: Wiley
Date: 24-05-2012
DOI: 10.1002/JBM.A.34150
Abstract: Extracellular matrix (ECM) scaffolds derived from cultured cells have drawn increasing attention for use in tissue engineering. We have developed a method to prepare cultured cell-derived ECM scaffolds by combining three-dimensional cell culture, decellularization, and selective template removal. Cell-ECM-template complexes were first formed by culture of cells in a poly(lactic-co-glycolic acid) (PLGA) mesh template to deposit their own ECM. The complexes were subsequently decellularized to remove cellular components. Finally, the PLGA template was selectively removed to obtain the ECM scaffolds. Seven decellularization methods were compared for their decellularization effects during scaffold preparation. They were: freeze-thaw cycling (-80°C, six times) with ammonia water (25 mM) 0.1% Triton™ X-100 (TX100) with 1.5M KCl aqueous solution freeze-thaw cycling alone ammonia water alone TX100 extraction osmotic shock with 1.5M KCl and freeze-thaw cycling with 3M NaCl. Among these methods, the methods of freeze-thaw cycling with NH(4) OH and TX100 with 1.5M KCl showed the best effect on the removal of cellular components from the complexes, while the other five methods could only partially remove cellular components. The ECM scaffolds prepared by these two methods had similar gross appearances and microstructures. In vivo implantation of the ECM scaffolds prepared by these two methods induced mild host responses. The two decellularization methods were demonstrated to be effective for preparation of cultured cell-derived ECM scaffolds.
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.ACTBIO.2011.09.008
Abstract: The capacity to induce rapid vascular ingrowth during new bone formation is an important feature of biomaterials that are to be used for bone regeneration. Akermanite, a Ca-, Mg- and Si-containing bioceramic, has been demonstrated to be osteoinductive and to promote bone repair. This study further demonstrates the ability of akermanite to promote angiogenesis and investigates the mechanism of this behavior. The akermanite ion extract predominantly caused Si-ion-stimulated proliferation of human aortic endothelial cells. The Si ion in the extract was the most important component for the effect and the most effective concentration was found to be 0.6-2 μg ml(-1). In this range of Si ion concentration, the stimulating effect of the ceramic ion extract was demonstrated by the morphology of cells at the primary, interim and late stages during in vitro angiogenesis using ECMatrix™. The akermanite ion extract up-regulated the expression of genes encoding the receptors of proangiogenic cytokines and also increased the expression level of genes encoding the proangiogenic downstream cytokines, such as nitric oxide synthase and nitric oxide synthesis. Akermanite implanted in rabbit femoral condyle model promoted neovascularization after 8 and 16 weeks of implantation, which further confirmed its stimulation effect on angiogenesis in vivo. These results indicate that akermanite ceramic, an appropriate Si ion concentration source, could induce angiogenesis through increasing gene expression of proangiogenic cytokine receptors and up-regulated downstream signaling. To our knowledge, akermanite ceramic is the first Si-containing ceramic demonstrated to be capable of inducing angiogenesis during bone regeneration.
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.ACTBIO.2013.12.042
Abstract: Scaffold pore size is an important factor affecting tissue regeneration efficiency. The effect of pore size on cartilage tissue regeneration was compared by using four types of collagen porous scaffolds with different pore sizes. The collagen porous scaffolds were prepared by using pre-prepared ice particulates that had diameters of 150-250, 250-355, 355-425 and 425-500μm. All the scaffolds had spherical large pores with good interconnectivity and high porosity that facilitated cell seeding and spatial cell distribution. Chondrocytes adhered to the walls of the spherical pores and showed a homogeneous distribution throughout the scaffolds. The in vivo implantation results indicated that the pore size did not exhibit any obvious effect on cell proliferation but exhibited different effects on cartilage regeneration. The collagen porous scaffolds prepared with ice particulates 150-250μm in size best promoted the expression and production of type II collagen and aggrecan, increasing the formation and the mechanical properties of the cartilage.
Publisher: SAGE Publications
Date: 05-2011
Abstract: A micropatterned surface with different area ratios of cell-adhesive to nonadhesive surfaces was prepared by micropatterning poly(vinyl alcohol) on a polystyrene plate using photolithography. A gradient pattern of mesenchymal stem cells of different cell densities was generated by culturing the cells on a micropatterned surface. The effects of the cell density gradient on cell functions such as proliferation and differentiation were investigated. Cells seeded at a low density proliferated faster than cells seeded at a high density. Although mesenchymal stem cells seeded at both low and high densities showed osteogenic differentiation, the higher cell seeding density could initiate osteogenic differentiation at a faster rate than the low cell density. And high cell density was required to induce chondrogenic differentiation.
Publisher: Informa UK Limited
Date: 08-05-2012
Publisher: Informa Healthcare
Date: 09-11-2010
DOI: 10.1517/14712598.2010.534079
Abstract: Biomimetic scaffolds and substrates of extracellular matrices (ECMs) play an important role in the regulation of cell function and in the guidance of new tissue regeneration, as an ECM has the intrinsic cues necessary to communicate with and dictate to cells. This paper reviews the latest developments in ECM scaffolds and substrates obtained from decellularized tissues, organs or cultured cells and their application in tissue engineering. The ECM composition, structure, interaction with surrounding cells, preparation method and usage in the regeneration of various tissues and organs are summarised. The advantages and challenges of decellularized matrices are highlighted. Similarity in the composition, microstructure and biomechanical properties of the decellularized scaffolds and substrates to those of the native tissues and organs maximizes the promotion effect in the regeneration of both structural and functional tissues and organs. Simple tissues as well as complicated organs have been decellularized and decellularization methods have been optimized to completely remove the cellular components while keeping the ECM intact.
Publisher: SAGE Publications
Date: 02-09-2009
Abstract: The effects of hardystonite (Ca 2 ZnSi 2 O 7 , CSZn) and tricalcium phosphate (β-TCP) on the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (MSCs) were compared by directly culturing MSCs on ceramic disks (contact mode) or separately culturing cells with ceramic disks (non-contact mode). In non-contact mode, the CSZn ceramic supported MSC proliferation more strongly than did the β-TCP ceramic. However, in contact mode, the MSCs proliferated more quickly on the β-TCP ceramic than they did on the CSZn ceramic. Alkaline phosphatase (ALP) staining and osteogenic gene expression analysis showed that the CSZn and β-TCP ceramics had significant effects on the promotion of the osteogenic differentiation of MSCs in both non-contact and contact mode. Furthermore, in contact mode, the CSZn disk promoted the osteogenic differentiation of MSCs more strongly than did the β-TCP disks. Even without the induction of dexamethasone and β-glycerophosphate, CSZn stimulated the osteogenic differentiation of MSCs. These results suggest that CSZn ceramic would be a useful candidate material for bone regeneration and hard tissue engineering.
Publisher: Elsevier BV
Date: 09-2012
DOI: 10.1016/J.BIOMATERIALS.2012.05.038
Abstract: The introduction of bioactive molecules into three-dimensional porous scaffolds to mimic the in vivo microenvironment is a promising strategy for tissue engineering and stem cell research. In this study, bone morphogenetic protein-4 (BMP4) was spatially immobilized in a collagen-PLGA hybrid scaffold with a fusion BMP4 composed of an additional collagen-binding domain derived from fibronectin (CBD-BMP4). CBD-BMP4 bound to the collagen-PLGA hybrid scaffold and the BMP4-immobilized hybrid scaffold supported cell adhesion and proliferation. The osteogenic induction effect of the immobilized CBD-BMP4 was investigated with three-dimensional culture of human bone marrow-derived mesenchymal stem cells in the BMP4-immobilized collagen-PLGA hybrid scaffold. The in vivo implantation experiment demonstrated that the immobilized CBD-BMP4 maintained its osteoinductive activity, being capable of up-regulating osteogenic gene expression and biomineralization. The strong osteoinductivity of the BMP4-immobilized scaffold suggests it should be useful for bone tissue engineering, stem cell function manipulation and bone substitutes.
Publisher: Wiley
Date: 20-04-2011
DOI: 10.1002/BTPR.592
Abstract: Cell-derived extracellular matrices (ECMs) are a key factor in regulating cell functions in tissue engineering and regenerative medicine. The fact that cells are surrounded by their specific ECM in vivo elicits the need to elucidate the effects of ECM derived from different cell sources on cell functions. Here, three types of ECM were prepared by decellularizing cultured chondrocytes, fibroblasts, and mesenchymal stem cells (MSC) and used for chondrocyte culture to compare their effects on chondrocyte adhesion, proliferation, and differentiation. Chondrocyte adhesion to the chondrocyte-derived ECM was greater than those to the fibroblast- and MSC-derived ECM. Chondrocyte proliferation on the chondrocyte-derived ECM was lower than those on the fibroblast- and MSC-derived ECM. The ECM showed no evident effect on chondrocyte differentiation. The effects of ECM on cell functions depended on the cell source used to prepare the ECM.
Publisher: Elsevier BV
Date: 09-2013
Publisher: SAGE Publications
Date: 09-02-2012
Abstract: Angiogenesis is an important process used to guide the regeneration of functional tissues and organs. The incorporation of inductive cues into scaffolds to control angiogenesis is an attractive strategy for scaffold preparation. Four mesh-type scaffolds, including a vascular endothelial growth factor-embedded poly(d,l-lactic- co-glycolic acid) mesh, a vascular endothelial growth factor-coated poly(d,l-lactic- co-glycolic acid) mesh, a collagen-coated poly(d,l-lactic- co-glycolic acid) mesh, and a poly(d,l-lactic- co-glycolic acid) mesh, were compared for their inductive effects on the formation of a micropatterned capillary network. Following subcutaneous implantation, all of the scaffolds induced the formation of micropatterned capillary networks, as observed at 2 and 6 weeks after implantation. The vascular endothelial growth factor-embedded mesh and the vascular endothelial growth factor-coated mesh promoted a higher degree of blood vessel formation than the collagen-coated mesh and the poly(d,l-lactic- co-glycolic acid) mesh. The capillary density in the vascular endothelial growth factor-embedded mesh and the vascular endothelial growth factor-coated mesh increased with time following implantation. The macrophages that surrounded the scaffolds were similar for all the meshes. The microstructure of the poly(d,l-lactic- co-glycolic acid) mesh determined the micropattern of the capillary network, and vascular endothelial growth factor provided a synergistic effect on the micropatterned angiogenesis process.
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.BBRC.2009.01.174
Abstract: The effect of cell density on the adipogenic differentiation of human bone marrow-derived mesenchymal stem cells (MSCs) was investigated by using a patterning technique to induce the formation of a cell density gradient on a micropatterned surface. The adipogenic differentiation of MSCs at a density gradient from 5 x 10(3) to 3 x 10(4) cells/cm2 was examined. Lipid vacuoles were observed at all cell densities after 1-3 weeks of culture in adipogenic differentiation medium although the lipid vacuoles were scarce at the low cell density and abundant at the high cell density. Real-time RT-PCR analysis showed that adipogenesis marker genes encoding peroxisome proliferator-activated receptor gamma2 (PPARgamma2), lipoprotein lipase (LPL), and fatty acid binding protein-4 (FABP4) were detected in the MSCs cultured at all cell densities. The results suggest that there was no apparent effect of cell density on the adipogenic differentiation of human MSCs.
Publisher: Wiley
Date: 30-12-2011
DOI: 10.1002/JBM.A.34003
Abstract: The loss of cartilaginous phenotype during in vitro expansion culture of chondrocytes is a major barrier for the application of cartilage tissue engineering. The use of matrices mimicking the in vivo extracellular matrix (ECM) microenvironment is anticipated to be an efficient method to suppress chondrocyte phenotype loss. In this study, we developed several types of ECM derived from serially passaged chondrocytes for use as cell-culture substrata and compared their effects on chondrocyte functions. Primary bovine chondrocytes and serially passaged chondrocytes (at passages 2 and 6) were cultured on tissue-culture polystyrene. After culture, the cellular components were selectively removed from the ECM deposited by the cells. The remaining ECM proteins were used as cell-culture substrata. The composition of the deposited ECM depended on the culture stage of the serially passaged chondrocytes used for the ECM production. The deposited ECM supported the adhesion and proliferation of chondrocytes. The effects of the ECM on the chondrocyte dedifferentiation during in vitro passage culture differed dramatically depending on the phenotype of the chondrocytes used to produce the ECM. The primary chondrocyte-derived ECM delayed the chondrocyte dedifferentiation during in vitro passage culture and is a good candidate for chondrocyte subculture for tissue engineering.
Publisher: Informa UK Limited
Date: 12-2012
Publisher: Elsevier BV
Date: 10-2008
DOI: 10.1016/J.BBRC.2008.07.112
Abstract: Cartilaginous gene expression decreased when chondrocytes were expanded on cell-culture plates. Understanding the dedifferentiation mechanism may provide valuable insight into cartilage tissue engineering. Here, we demonstrated the relationship between the nuclear shape and gene expression during in vitro expansion culture of chondrocytes. Specifically, the projected nuclear area increased and cartilaginous gene expressions decreased during in vitro expansion culture. When the nuclear deformation was recovered by cytochalasin D treatment, aggrecan expression was up-regulated and type I collagen (Col1a2) expression was down-regulated. These results suggest that nuclear deformation may be one of the mechanisms for chondrocyte dedifferentiation during in vitro expansion culture.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2SM25718A
Publisher: IOP Publishing
Date: 11-07-2011
DOI: 10.1088/1748-6041/6/4/045011
Abstract: Three-dimensional porous scaffolds play an important role in tissue engineering and regenerative medicine. Structurally, these porous scaffolds should have an open and interconnected porous architecture to facilitate a homogeneous cell distribution. Moreover, the scaffolds should be mechanically strong to support new tissue formation. We developed a novel type of funnel-like collagen sponge using embossing ice particulates as a template. The funnel-like collagen sponges could promote the homogeneous cell distribution, ECM production and chondrogenesis. However, the funnel-like collagen sponges deformed during cell culture due to their weak mechanical strength. To solve this problem, we reinforced the funnel-like collagen sponges with a knitted poly(D,L-lactic-co-glycolic acid) (PLGA) mesh by hybridizing these two types of materials. The hybrid scaffolds were used to culture bovine articular chondrocytes. The cell adhesion, distribution, proliferation and chondrogenesis were investigated. The funnel-like structure promoted the even cell distribution and homogeneous ECM production. The PLGA knitted mesh protected the scaffold from deformation during cell culture. Histological and immunohistochemical staining and cartilaginous gene expression analyses revealed the cartilage-like properties of the cell/scaffold constructs after in vivo implantation. The hybrid scaffold, composed of a funnel-like collagen sponge and PLGA mesh, would be a useful tool for cartilage tissue engineering.
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.BIOMATERIALS.2010.04.019
Abstract: Three-dimensional porous scaffolds of collagen have been widely used for tissue engineering and regenerative medicine. In this study, we fabricated funnel-like collagen sponges with open surface pore structures by a freeze-drying method that used embossing ice particulates as a template. By controlling the size of the ice particulates and the temperature of freezing, collagen sponges with different pore structures were prepared. To investigate the effects of different pore structures on cartilage regeneration, the funnel-like collagen sponges were used to culture bovine articular chondrocytes. Scaffolds that were prepared with 400microm ice particulate templates and a freezing temperature of -3 degrees C resulted in the best cell distribution, ECM production, and chondrogenesis. Although funnel-like collagen sponges prepared with 400microm ice particulate templates and a freezing temperature of -1 degrees C and 720microm ice particulates and a freezing temperature of -3 degrees C, showed even cell distribution, the cell seeding efficiencies and sGAG amount per cell were low. However, the scaffolds prepared with 400microm ice particulate templates and a freezing temperature of -5 degrees C or -10 degrees C showed a limited effect on the improvement of cell distribution and chondrogenesis. Control collagen sponges without ice particulates failed to support the formation of homogenous cartilage-like tissue. These results indicate that funnel-like collagen sponges were superior to control collagen sponges and that scaffolds prepared with 400microm ice particulate templates at -3 degrees C were optimal for cartilage tissue engineering.
Publisher: SAGE Publications
Date: 08-2013
Abstract: Appropriate pore structures and mechanical properties are required for scaffolds that are used for tissue engineering and regenerative medicine. In this study, pre-prepared ice particulates were used as a porogen material to prepare collagen porous scaffolds with well-controlled pore structures and improved mechanical properties. Porogen ice particulates initiated the formation of interconnected large spherical pores surrounded by small pores. The large spherical pores were well compacted and increased the elastic modulus of the scaffolds. The unique pore structures facilitated cell penetration, resulting in a homogeneous cell distribution throughout the scaffolds. The excellent mechanical properties protected the scaffolds from deformation during cell culturing and implantation. The collagen porous scaffolds facilitated cartilage regeneration when bovine articular chondrocytes were cultured in these scaffolds. The use of pre-prepared ice particulates as a porogen material proved to be a useful method to control the pore structure and improve the mechanical properties of collagen-based porous scaffolds.
Publisher: Mary Ann Liebert Inc
Date: 06-2010
Publisher: Wiley
Date: 16-02-2012
DOI: 10.1002/BTPR.1520
Abstract: Micropatterning of biological cues is important for the guided formation of neuronal outgrowth and neuronal differentiation. Nerve growth factor (NGF) was micropatterned in a three-dimensional collagen sponges by using micropatterned ice lines that were composed of collagen and NGF. The micropatterned ice lines were prepared by a dispersing machine. PC12 cells were cultured in the NGF-micropatterned collagen sponges and showed micropatterned neurite outgrowth. The neurite outgrowth followed the micropattern of NGF with more neurite outgrowth in the collagen/NGF lines than in the regions between the collagen/NGF lines. The micropattern of the NGF and the neurite network of the PC12 cells can be manipulated by controlling the micropattern of the NGF. The three-dimensional porous scaffolds prepared by this method will have a potential application for the regeneration and repair of the nervous system.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6TB02748B
Abstract: A new platform for the culture of pancreatic islets that improves the cell viability and quality. Paving the way for a highly efficient islet clinical transport.
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.BIOMATERIALS.2010.12.016
Abstract: Development of autologous scaffolds has been highly desired for implantation without eliciting adverse inflammatory and immune responses. However, it has been difficult to obtain autologous scaffolds by tissue decellularization because of the restricted availability of autologous donor tissues from a patient. Here we report a method to prepare autologous extracellular matrix (aECM) scaffolds by combining culture of autologous cells in a three-dimensional template, decellularization, and template removal. The aECM scaffolds showed excellent biocompatibility when implanted. We anticipate that "Full Autologous Tissue Engineering" can be realized to minimize undesirable host tissue responses by culturing the patient's own cells in an aECM scaffold.
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.BIOMATERIALS.2011.08.091
Abstract: Cell-derived extracellular matrix (ECM) scaffolds have received considerable interest for tissue engineering applications. In this study, ECM scaffolds derived from mesenchymal stem cell (MSC), chondrocyte, and fibroblast were prepared by culturing cells in a selectively removable poly(lactic-co-glycolic acid) (PLGA) template. These three types of ECM scaffolds were used for in vitro cultures of MSC and fibroblasts to examine their potential as scaffolds for cartilage and skin tissue engineering. The MSC were cultured in MSC- and chondrocyte-derived ECM scaffolds. The ECM scaffolds supported cell adhesion, promoted both cell proliferation and the production of ECM and demonstrated a stronger stimulatory effect on the chondrogenesis of MSC compared with a conventional pellet culture method. Histological and immunohistochemical staining indicated that cartilage-like tissues were regenerated after the MSC were cultured in ECM scaffolds. Fibroblasts were cultured in the fibroblast-derived ECM scaffolds. Fibroblasts proliferated and produced ECM to fill the pores and spaces in the scaffold. After 2 weeks of culture, a uniform multilayered tissue was generated with homogenously distributed fibroblasts. Cell-derived ECM scaffolds have been demonstrated to facilitate tissue regeneration and will be a useful tool for tissue engineering.
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.ACTBIO.2013.04.024
Abstract: Ideal biomaterials for bone tissue engineering should have the capability to guide the osteogenic differentiation of mesenchymal stem cells and, at the same time, to stimulate angiogenesis of endothelia cells. In this study it was found that three Ca-Mg-Si-containing bioceramics (bredigite Ca7MgSi4O16, akermanite Ca2MgSi2O7 and diopside CaMgSi2O6) had osteogenic and angiogenic potential. The effects of three silicate ceramics on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and the angiogenesis of human aortic endothelial cells (HAECs) were explored in comparison with β-tricalcium phosphate (β-TCP) bioceramics. The proliferation, alkaline phosphatase (ALPase) activity and bone-related gene expression (COL1, ALPase, OP, BSP and OC) of hBMSCs were significantly enhanced upon stimulation with ionic extracts of these silicate bioceramics. In addition, the results showed that extracts from the three silicate bioceramics also stimulated HAEC proliferation and in vitro angiogenesis with improved NO synthesis and angiogenic gene expression (KDR, FGFR1, ACVRL1 and NOS3). Among the three silicate ceramics bredigite showed the highest osteogenic and angiogenic potential and with the highest extract Si (possibly Si(OH)3O(-)) concentration, while diopside had the lowest osteogenic and angiogenic potential with the lowest extract Si concentration. Furthermore, it was found that the concentration of Si ions in extracts of the three silicate bioceramics was obviously higher than that of β-TCP ceramics, indicating an important role of Si ions in stimulating cell proliferation, osteogenic differentiation and angiogenesis. The results suggest that the silicate-based akermanite and bredigite ceramics might be good scaffold biomaterials for bone tissue engineering applications due to their distinctive dual functions of osteogenesis/angiogenesis stimulation.
No related grants have been discovered for Guoping Chen.