The Experts below are selected from a list of 28986 Experts worldwide ranked by ideXlab platform
Eben Alsberg - One of the best experts on this subject based on the ideXlab platform.
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets tre...
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets treated with exogenous TGF-β1. Cartilage formation was confirmed histologically via observation of cartilage-like morphology and GAG staining. This is the first demonstration of the self-assembly of hASCs into high-density Cell sheets capable of forming cartilage in the presence of exogenous TGF-β1 or with TGF-β1-releasing microspheres. Microsphere incorporation may bypass the need for extended in vitro culture, potentially enabling hASC sheets to be implanted more rapidly into defects to regenerate cartilage in vivo.
Lauren E Flynn - One of the best experts on this subject based on the ideXlab platform.
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the use of deCellularized adipose tissue to provide an inductive microenvironment for the adipogenic differentiation of human adipose derived stem Cells
Biomaterials, 2010Co-Authors: Lauren E FlynnAbstract:The development of an engineered adipose tissue substitute, capable of supporting reliable, predictable, and complete fat tissue formation, would be of significant value in the fields of plastic and reconstructive surgery. Towards the goal of engineering an optimized microenvironment for adipogenesis, a deCellularization strategy was developed for adipose tissue, which yielded 3-D scaffolds with preserved extraCellular matrix architecture. A significant volume of scaffolding material could be obtained from a human tissue source that is commonly discarded. Histology, immunohistochemistry, and scanning electron microscopy confirmed the efficacy and reproducibility of the approach, and also indicated that the basement membrane was conserved in the processed matrix, including laminin and collagen type IV. Seeding experiments with human adipose-derived stem Cells indicated that the deCellularized adipose tissue (DAT) provided an inductive microenvironment for adipogenesis, supporting the expression of the master regulators PPARγ and CEBPα, without the need for exogenous differentiation factors. High levels of adipogenic gene expression and glycerol-3-phosphate dehydrogenase activity were observed in the induced DAT scaffolds, as compared to Cells grown in monolayer or Cell Aggregate culture. The protein data emphasized the importance of the Cell donor source in the development of tissue-engineering strategies for large-volume soft tissue regeneration.
Phuong N Dang - One of the best experts on this subject based on the ideXlab platform.
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets tre...
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets treated with exogenous TGF-β1. Cartilage formation was confirmed histologically via observation of cartilage-like morphology and GAG staining. This is the first demonstration of the self-assembly of hASCs into high-density Cell sheets capable of forming cartilage in the presence of exogenous TGF-β1 or with TGF-β1-releasing microspheres. Microsphere incorporation may bypass the need for extended in vitro culture, potentially enabling hASC sheets to be implanted more rapidly into defects to regenerate cartilage in vivo.
TE Hardingham - One of the best experts on this subject based on the ideXlab platform.
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bone marrow derived mesenchymal stem Cells express the pericyte marker 3g5 in culture and show enhanced chondrogenesis in hypoxic conditions
Journal of Orthopaedic Research, 2010Co-Authors: Wasim S Khan, Adetola B Adesida, Emma T Lowe, TE HardinghamAbstract:Bone marrow-derived mesenchymal stem Cells are a potential source of Cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in some Cells. In this study, bone marrow-derived stem Cells were characterized and the effects of hypoxia on chondrogenesis investigated. Adherent bone marrow colony-forming Cells were characterized for stem Cell surface epitopes, and then cultured as Cell Aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions. The Cells stained strongly for markers of adult mesenchymal stem Cells, and a high number of Cells were also positive for the pericyte marker 3G5. The Cells showed a chondrogenic response in Cell Aggregate cultures and, in lowered oxygen, there was increased matrix accumulation of proteoglycan, but less Cell proliferation. In hypoxia, there was increased expression of key transcription factor SOX6, and of collagens II and XI, and aggrecan. Pericytes are a candidate stem Cell in many tissue, and our results show that bone marrow-derived mesenchymal stem Cells express the pericyte marker 3G5. The response to chondrogenic culture in these Cells was enhanced by lowered oxygen tension. This has important implications for tissue engineering applications of bone marrow-derived stem Cells. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:834–840, 2010
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human meniscus Cells express hypoxia inducible factor 1α and increased sox9 in response to low oxygen tension in Cell Aggregate culture
Arthritis Research & Therapy, 2007Co-Authors: Adetola B Adesida, Lisa M Grady, Wasim S Khan, Jane S Millwardsadler, Donald Salter, TE HardinghamAbstract:In previous work we demonstrated that the matrix-forming phenotype of cultured human Cells from whole meniscus was enhanced by hypoxia (5% oxygen). Because the meniscus contains an inner region that is devoid of vasculature and an outer vascular region, here we investigate, by gene expression analysis, the separate responses of Cells isolated from the inner and outer meniscus to lowered oxygen, and compared it with the response of articular chondrocytes. In Aggregate culture of outer meniscus Cells, hypoxia (5% oxygen) increased the expression of type II collagen and SOX9 (Sry-related HMG box-9), and decreased the expression of type I collagen. In contrast, with inner meniscus Cells, there was no increase in SOX9, but type II collagen and type I collagen increased. The articular chondrocytes exhibited little response to 5% oxygen in Aggregate culture, with no significant differences in the expression of these matrix genes and SOX9. In both Aggregate cultures of outer and inner meniscus Cells, but not in chondrocytes, there was increased expression of collagen prolyl 4-hydroxylase (P4H)α(I) in response to 5% oxygen, and this hypoxia-induced expression of P4Hα(I) was blocked in monolayer cultures of meniscus Cells by the hypoxia-inducible factor (HIF)-1α inhibitor (YC-1). In fresh tissue from the outer and inner meniscus, the levels of expression of the HIF-1α gene and downstream target genes (namely, those encoding P4Hα(I) and HIF prolyl 4-hydroxylase) were significantly higher in the inner meniscus than in the outer meniscus. Thus, this study revealed that inner meniscus Cells were less responsive to 5% oxygen tension than were outer meniscus Cells, and they were both more sensitive than articular chondrocytes from a similar joint. These results suggest that the vasculature and greater oxygen tension in the outer meniscus may help to suppress cartilage-like matrix formation.
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The matrix-forming phenotype of cultured human meniscus Cells is enhanced after culture with fibroblast growth factor 2 and is further stimulated by hypoxia.
Arthritis Res Ther, 2006Co-Authors: TE HardinghamAbstract:Human meniscus Cells have a predominantly fibrogenic pattern of gene expression, but like chondrocytes they proliferate in monolayer culture and lose the expression of type II collagen. We have investigated the potential of human meniscus Cells, which were expanded with or without fibroblast growth factor 2 (FGF2), to produce matrix in three-dimensional Cell Aggregate cultures with a chondrogenic medium at low (5%) and normal (20%) oxygen tension. The presence of FGF2 during the expansion of meniscus Cells enhanced the re-expression of type II collagen 200-fold in subsequent three-dimensional Cell Aggregate cultures. This was increased further (400-fold) by culture in 5% oxygen. Cell Aggregates of FGF2-expanded meniscus Cells accumulated more proteoglycan (total glycosaminoglycan) over 14 days and deposited a collagen II-rich matrix. The gene expression of matrix-associated proteoglycans (biglycan and fibromodulin) was also increased by FGF2 and hypoxia. Meniscus Cells after expansion in monolayer can therefore respond to chondrogenic signals, and this is enhanced by FGF2 during expansion and low oxygen tension during Aggregate cultures.
Loran D Solorio - One of the best experts on this subject based on the ideXlab platform.
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets tre...
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driving cartilage formation in high density human adipose derived stem Cell Aggregate and sheet constructs without exogenous growth factor delivery
Tissue Engineering Part A, 2014Co-Authors: Phuong N Dang, Loran D Solorio, Eben AlsbergAbstract:An attractive Cell source for cartilage tissue engineering, human adipose-derived stem Cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1)-loaded gelatin microspheres. The amounts of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC Aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control Aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved GAG production similar to sheets treated with exogenous TGF-β1. Cartilage formation was confirmed histologically via observation of cartilage-like morphology and GAG staining. This is the first demonstration of the self-assembly of hASCs into high-density Cell sheets capable of forming cartilage in the presence of exogenous TGF-β1 or with TGF-β1-releasing microspheres. Microsphere incorporation may bypass the need for extended in vitro culture, potentially enabling hASC sheets to be implanted more rapidly into defects to regenerate cartilage in vivo.