The Experts below are selected from a list of 16569 Experts worldwide ranked by ideXlab platform
Hani A Awad - One of the best experts on this subject based on the ideXlab platform.
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chondrogenic differentiation of adipose derived adult stem cells by a Porous Scaffold derived from native articular cartilage extracellular matrix
Tissue Engineering Part A, 2009Co-Authors: Nai-chen Cheng, Bradley T Estes, Hani A Awad, Farshid GuilakAbstract:Adipose-derived adult stem cells (ASCs) have the ability to differentiate into a chondrogenic phenotype in response to specific environmental signals such as growth factors or artificial biomaterial Scaffolds. In this study, we examined the hypothesis that a Porous Scaffold derived exclusively from articular cartilage can induce chondrogenesis of ASCs. Human ASCs were seeded on Porous Scaffolds derived from adult porcine articular cartilage and cultured in standard medium without exogenous growth factors. Chondrogenesis of ASCs seeded within the Scaffold was evident by quantitative RT-PCR analysis for cartilage-specific extracellular matrix (ECM) genes. Histological and immunohistochemical examination showed abundant production of cartilage-specific ECM components—particularly, type II collagen—after 4 or 6 weeks of culture. After 6 weeks of culture, the cellular morphology in the ASC-seeded constructs resembled those in native articular cartilage tissue, with rounded cells residing in the glycosaminoglyc...
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Chondrogenic Differentiation of Adipose-Derived Adult Stem Cells by a Porous Scaffold Derived from Native Articular Cartilage Extracellular Matrix
Tissue Engineering Part A, 2009Co-Authors: Nai-chen Cheng, Bradley T Estes, Hani A AwadAbstract:Adipose-derived adult stem cells (ASCs) have the ability to differentiate into a chondrogenic phenotype in response to specific environmental signals such as growth factors or artificial biomaterial Scaffolds. In this study, we examined the hypothesis that a Porous Scaffold derived exclusively from articular cartilage can induce chondrogenesis of ASCs. Human ASCs were seeded on Porous Scaffolds derived from adult porcine articular cartilage and cultured in standard medium without exogenous growth factors. Chondrogenesis of ASCs seeded within the Scaffold was evident by quantitative RT-PCR analysis for cartilage-specific extracellular matrix (ECM) genes. Histological and immunohistochemical examination showed abundant production of cartilage-specific ECM components-particularly, type II collagen-after 4 or 6 weeks of culture. After 6 weeks of culture, the cellular morphology in the ASC-seeded constructs resembled those in native articular cartilage tissue, with rounded cells residing in the glycosaminoglycan-rich regions of the Scaffolds. Biphasic mechanical testing showed that the aggregate modulus of the ASC-seeded constructs increased over time, reaching 150 kPa by day 42, more than threefold higher than that of the unseeded controls. These results suggest that a Porous Scaffold derived from articular cartilage has the ability to induce chondrogenic differentiation of ASCs without exogenous growth factors, with significant synthesis and accumulation of ECM macromolecules, and the development of mechanical properties approaching those of native cartilage. These findings support the potential for a processed cartilage ECM as a biomaterial Scaffold for cartilage tissue engineering. Additional in vivo evaluation is necessary to fully recognize the clinical implication of these observations.
Nai-chen Cheng - One of the best experts on this subject based on the ideXlab platform.
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chondrogenic differentiation of adipose derived adult stem cells by a Porous Scaffold derived from native articular cartilage extracellular matrix
Tissue Engineering Part A, 2009Co-Authors: Nai-chen Cheng, Bradley T Estes, Hani A Awad, Farshid GuilakAbstract:Adipose-derived adult stem cells (ASCs) have the ability to differentiate into a chondrogenic phenotype in response to specific environmental signals such as growth factors or artificial biomaterial Scaffolds. In this study, we examined the hypothesis that a Porous Scaffold derived exclusively from articular cartilage can induce chondrogenesis of ASCs. Human ASCs were seeded on Porous Scaffolds derived from adult porcine articular cartilage and cultured in standard medium without exogenous growth factors. Chondrogenesis of ASCs seeded within the Scaffold was evident by quantitative RT-PCR analysis for cartilage-specific extracellular matrix (ECM) genes. Histological and immunohistochemical examination showed abundant production of cartilage-specific ECM components—particularly, type II collagen—after 4 or 6 weeks of culture. After 6 weeks of culture, the cellular morphology in the ASC-seeded constructs resembled those in native articular cartilage tissue, with rounded cells residing in the glycosaminoglyc...
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Chondrogenic Differentiation of Adipose-Derived Adult Stem Cells by a Porous Scaffold Derived from Native Articular Cartilage Extracellular Matrix
Tissue Engineering Part A, 2009Co-Authors: Nai-chen Cheng, Bradley T Estes, Hani A AwadAbstract:Adipose-derived adult stem cells (ASCs) have the ability to differentiate into a chondrogenic phenotype in response to specific environmental signals such as growth factors or artificial biomaterial Scaffolds. In this study, we examined the hypothesis that a Porous Scaffold derived exclusively from articular cartilage can induce chondrogenesis of ASCs. Human ASCs were seeded on Porous Scaffolds derived from adult porcine articular cartilage and cultured in standard medium without exogenous growth factors. Chondrogenesis of ASCs seeded within the Scaffold was evident by quantitative RT-PCR analysis for cartilage-specific extracellular matrix (ECM) genes. Histological and immunohistochemical examination showed abundant production of cartilage-specific ECM components-particularly, type II collagen-after 4 or 6 weeks of culture. After 6 weeks of culture, the cellular morphology in the ASC-seeded constructs resembled those in native articular cartilage tissue, with rounded cells residing in the glycosaminoglycan-rich regions of the Scaffolds. Biphasic mechanical testing showed that the aggregate modulus of the ASC-seeded constructs increased over time, reaching 150 kPa by day 42, more than threefold higher than that of the unseeded controls. These results suggest that a Porous Scaffold derived from articular cartilage has the ability to induce chondrogenic differentiation of ASCs without exogenous growth factors, with significant synthesis and accumulation of ECM macromolecules, and the development of mechanical properties approaching those of native cartilage. These findings support the potential for a processed cartilage ECM as a biomaterial Scaffold for cartilage tissue engineering. Additional in vivo evaluation is necessary to fully recognize the clinical implication of these observations.
Changyou Gao - One of the best experts on this subject based on the ideXlab platform.
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gene activated matrix bone marrow derived mesenchymal stem cells constructs regenerate sweat glands like structure in vivo
Scientific Reports, 2017Co-Authors: Pranish Kolakshyapati, Chunye Chen, Mingxia Zhang, Weiqiang Tan, Changyou GaoAbstract:It is a significant challenge to regenerate full-thickness skin defects with sweat glands. Various skin substitutes have been developed to resolve this issue with minimal success. In this study, to yield a novel construct for in situ regeneration of sweat glands, the collagen-chitosan Porous Scaffold was combined with Lipofectamine 2000/pDNA-EGF complexes to obtain the gene-activated Scaffold (GAS), which was then seeded with bone marrow-derived mesenchymal stem cells (BM-MSCs). The Porous Scaffold functionalized as a reservoir for the incorporated gene complexes which were released in a sustained manner. The seeded BM-MSCs were transfected in situ by the released complexes and specially differentiated into sweat gland cells in vitro under the induction of the expressed epidermal growth factor (EGF). Application in vivo of the GAS/BM-MSCs constructs on the full-thickness skin defects of SD rats confirmed that GAS/BM-MSCs could accelerate the wound healing process and induce the in situ regeneration of the full-thickness skin with sweat gland-like structures. Analyzed by immunohistochemical staining, RT-qPCR and Western-blotting, the levels of the major sweat gland markers such as carcino-embryonic antigen (CEA), cytokeratin 8 (CK8) and cytokeratin 14 (CK14) were all up-regulated, indicating that GAS/BM-MSCs can facilitate the regeneration of sweat glands-like structure in vivo.
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preparation of polycaprolactone microspheres aggregated Scaffold with ultra big pores and fuzzy sphere surface by a one step phase separation method
Journal of Biomedical Materials Research Part A, 2013Co-Authors: Meicong Wang, Pengfei Jiang, Changyou GaoAbstract:A microspheres-aggregated Scaffold with ultra big pores (over 300 lm) and fuzzy microspheres is fabricated by incubating polycaprolactone (PCL)/tetrahydrofuran (THF) solution in a � 20� C refrigerator, following by freeze-drying. Formation of the Scaffold is mainly governed by the crystalli- zation of the PCL polymer at appropriate conditions. All the 10-20% PCL/THF solutions yield the microspheres-aggregated Scaffolds when the initial solution temperature is higher than 37 � C, whereas the 10-15% solutions form dense membranes when the initial solution temperature is below 25 � C. The size of the microspheres and pores is as large as 70-150 lm and 170-816 lm, respectively. The PCL microspheres-aggregated Scaffold can better support the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs) compared to the traditional Porous Scaffold obtained by a porogen leach- ing method. The tendencies of chondrogenesis and osteo- genesis differentiation of BMSCs are observed on the microspheres-aggregated Scaffold and the ordinary Porous Scaffold, respectively. V C
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facile fabrication of the glutaraldehyde cross linked collagen chitosan Porous Scaffold for skin tissue engineering
Materials Science and Engineering: C, 2012Co-Authors: Yunyun Liu, Changyou GaoAbstract:Abstract Porous Scaffold is one of the key factors in skin tissue engineering. In this study, a facile method was developed to prepare the glutaraldehyde (GA) cross-linked collagen/chitosan Porous Scaffold (S2). The properties of S2 were compared with the Scaffolds prepared by the traditional method (S1). Compared to the rough surface and collapsed inner structure of S1, S2 showed a smooth surface and controlled size. After treated by GA with same concentration, S1 and S2 showed the similar swelling ratios, which are big enough to ensure the nutrient supply in the early stage of wound healing. The effects of the fabrication methods as well as the GA concentration on the cross-linking degree and in vitro degradation degree of the Scaffolds were studied. It was found that the cross-linking degree of S2-0.25% was much higher than that of S1. Investigation of the tensile and compression properties of the Scaffolds found that the mechanical property of S2-0.04% is closest to that of S1. High performance liquid chromatography (HPLC) was applied to determine the residual GA. The results proved that, compared to water rinse, oven drying is a feasible and effective method to remove the residual GA. Finally, the cytocompatibility of S2 was evaluated by in vitro culture of fibroblasts. The results of cell morphology and cell viability proved that S2-0.04% could retain the original good cytocompatibility of S1 to accelerate cell infiltration and proliferation effectively. All these results indicate that it is a feasible method to prepare the GA cross-linked collagen/chitosan Scaffold.
Farshid Guilak - One of the best experts on this subject based on the ideXlab platform.
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chondrogenic differentiation of adipose derived adult stem cells by a Porous Scaffold derived from native articular cartilage extracellular matrix
Tissue Engineering Part A, 2009Co-Authors: Nai-chen Cheng, Bradley T Estes, Hani A Awad, Farshid GuilakAbstract:Adipose-derived adult stem cells (ASCs) have the ability to differentiate into a chondrogenic phenotype in response to specific environmental signals such as growth factors or artificial biomaterial Scaffolds. In this study, we examined the hypothesis that a Porous Scaffold derived exclusively from articular cartilage can induce chondrogenesis of ASCs. Human ASCs were seeded on Porous Scaffolds derived from adult porcine articular cartilage and cultured in standard medium without exogenous growth factors. Chondrogenesis of ASCs seeded within the Scaffold was evident by quantitative RT-PCR analysis for cartilage-specific extracellular matrix (ECM) genes. Histological and immunohistochemical examination showed abundant production of cartilage-specific ECM components—particularly, type II collagen—after 4 or 6 weeks of culture. After 6 weeks of culture, the cellular morphology in the ASC-seeded constructs resembled those in native articular cartilage tissue, with rounded cells residing in the glycosaminoglyc...
Giovanni Magenes - One of the best experts on this subject based on the ideXlab platform.
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effects of electromagnetic stimulation on calcified matrix production by saos 2 cells over a polyurethane Porous Scaffold
Tissue Engineering, 2006Co-Authors: Lorenzo Fassina, Livia Visai, Francesco Benazzo, Laura Benedetti, Alberto Calligaro, Maria Gabriella Cusella De Angelis, Aurora Farina, Valentina Maliardi, Giovanni MagenesAbstract:There is increasing interest in designing new biomaterials that could potentially be used in the form of Scaffolds as bone substitutes. In this study we used a hydrophobic crosslinked polyurethane in a typical tissue-engineering approach, that is, the seeding and in vitro culturing of cells using a Porous Scaffold. Using an electromagnetic bioreactor (magnetic field intensity, 2 mT; frequency, 75 Hz), we investigated the effect of the electromagnetic stimulation on SAOS-2 human osteoblast proliferation and calcified matrix production. Cell proliferation was twice as high; expression of decorin, osteocalcin, osteopontin, type I collagen, and type III collagen was greater (1.3, 12.2, 12.1, 10.0, and 10.5 times as great, respectively); and calcium deposition was 5 times as great as under static conditions without electromagnetic stimulation. RT-PCR analysis revealed the electromagnetically upregulated transcription specific for decorin, fibronectin, osteocalcin, osteopontin, transforming growth factor-beta, type I collagen, and type III collagen. The immunolocalization of the extracellular matrix constituents showed their colocalization in the cell-rich areas. The bioreactor and the polyurethane foam were designed to obtain cell colonization and calcified matrix deposition. This cultured biomaterial could be used, in clinical applications, as an osteoinductive implant for bone repair.
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calcified matrix production by saos 2 cells inside a polyurethane Porous Scaffold using a perfusion bioreactor
Tissue Engineering, 2005Co-Authors: Lorenzo Fassina, Livia Visai, L Asti, Francesco Benazzo, Pietro Speziale, M C Tanzi, Giovanni MagenesAbstract:The repair and regeneration of damaged or resected bone are problematic. Bone autografts show optimal skeletal incorporation, but often bring about complications. Hence, there is increasing interest in designing new biomaterials that could potentially be used in the form of Scaffolds as bone substitutes. In this study we used a hydrophobic cross-linked polyurethane in a typical tissue-engineering approach, that is, the seeding and in vitro culturing of cells within a Porous Scaffold. The polyurethane Porous Scaffold had an average pore diameter of 624 µm. Using a perfusion bioreactor, we investigated the effect of shear stress on SAOS-2 human osteoblast proliferation and calcified matrix production. The physical, morphological, and compressive properties of the polyurethane foam were characterized. At a Scaffold perfusion rate of 3 mL/min, in comparison with static conditions without perfusion, we observed 33% higher cell proliferation; higher secretion of osteopontin, osteocalcin, decorin, and type I col...