Author
Vassilis Karageorgiou
Other affiliations: ETH Zurich, Rutgers University
Bio: Vassilis Karageorgiou is an academic researcher from Tufts University. The author has contributed to research in topics: Fibroin & Tissue engineering. The author has an hindex of 14, co-authored 16 publications receiving 9522 citations. Previous affiliations of Vassilis Karageorgiou include ETH Zurich & Rutgers University.
Papers
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TL;DR: New fabrication techniques, such as solid-free form fabrication, can potentially be used to generate scaffolds with morphological and mechanical properties more selectively designed to meet the specificity of bone-repair needs.
5,470 citations
TL;DR: Biocompatibility studies of silk films (with or without covalently bound RGD) that were seeded with bone-marrow derived mesenchymal stem cells and cultured in vitro with human MSC suggest that purified degradable silk is biocompatible and the in vitro cell culture model gave inflammatory responses that were comparable to those observed in vivo.
737 citations
TL;DR: The ability of electrospun silk matrices to support BMSC attachment, spreading and growth in vitro, combined with a biocompatibility and biodegradable properties of the silk protein matrix, suggest potential use of these biomaterial matrices as scaffolds for tissue engineering.
623 citations
TL;DR: The preparation of water‐stable films from regenerated silk fibroin solutions, with reduced β‐sheet content, which support human adult stem‐cell expansion in vitro in a similar or improved fashion to the crystallized proteins in film form.
Abstract: Silk fibers have outstanding mechanical properties. These fibers are insoluble in organic solvents and water, are biocompatible, and exhibit slow biodegradation in vitro and in vivo due to the hydrophobic nature of the protein and the presence of a high content of β-sheet structure. Regenerated silk fibroin can be processed into a variety of materials normally stabilized by the induction of β-sheet formation through the use of solvents or by physical stretching. To extend the biomaterial utility of silk proteins, options to form water-stable silk-based materials with reduced β-sheet formation would be desirable. To address this need for more rapidly degradable silk biomaterials, we report the preparation of water-stable films from regenerated silk fibroin solutions, with reduced β-sheet content. The keys to this process are the preparation of concentrated (8 % by weight) aqueous solutions of fibroin and a subsequent water-based annealing procedure. These new materials degrade more rapidly due to the reduced β-sheet content, as determined in vitro via enzymatic hydrolysis, yet support human adult stem-cell expansion in vitro in a similar or improved fashion to the crystallized proteins in film form. These new silk-based materials extend the range of biomaterial properties that can be generated from this unique family of proteins.
576 citations
TL;DR: It is suggested that osteogenesis in cultured MSC can be modulated by scaffold properties and flow environment.
Abstract: We report studies of bone tissue engineering using human mesenchymal stem cells (MSCs), a protein substrate (film or scaffold; fast degrading unmodified collagen, or slowly degrading cross-linked collagen and silk), and a bioreactor (static culture, spinner flask, or perfused cartridge). MSCs were isolated from human bone marrow, characterized for the expression of cell surface markers and the ability to undergo chondrogenesis and osteogenesis in vitro, and cultured for 5 weeks. MSCs were positive for CD105/endoglin, and had a potential for chondrogenic and osteogenic differentiation. In static culture, calcium deposition was similar for MSC grown on collagen scaffolds and films. Under medium flow, MSC on collagen scaffolds deposited more calcium and had a higher alcaline phosphatase (AP) activity than MSC on collagen films. The amounts of DNA were markedly higher in constructs based on slowly degrading (modified collagen and silk) scaffolds than on fast degrading (unmodified collagen) scaffolds. In spinner flasks, medium flow around constructs resulted in the formation of bone rods within the peripheral region, that were interconnected and perpendicular to the construct surface, whereas in perfused constructs, individual bone rods oriented in the direction of fluid flow formed throughout the construct volume. These results suggest that osteogenesis in cultured MSC can be modulated by scaffold properties and flow environment.
572 citations
Cited by
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TL;DR: New fabrication techniques, such as solid-free form fabrication, can potentially be used to generate scaffolds with morphological and mechanical properties more selectively designed to meet the specificity of bone-repair needs.
5,470 citations
TL;DR: This review presents an overview of the electrospinning technique with its promising advantages and potential applications, and focuses on varied applications of electrospun fibers in different fields.
3,932 citations
TL;DR: This review summarizes the main advances published over the last 15 years, outlining the synthesis, biodegradability and biomedical applications ofBiodegradable synthetic and natural polymers.
3,801 citations
TL;DR: A review of the properties, biological performance, challenges and future directions of magnesium-based biomaterials can be found in this paper, where the authors explore the properties and challenges of magnesium biomaterial.
3,757 citations
TL;DR: Challenges in scaffold fabrication for tissue engineering such as biomolecules incorporation, surface functionalization and 3D scaffold characterization are discussed, giving possible solution strategies.
3,505 citations