The Experts below are selected from a list of 8997 Experts worldwide ranked by ideXlab platform
C. J. Kirkpatrick - One of the best experts on this subject based on the ideXlab platform.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. J. KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-beta1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-beta1.
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Endothelial cell cultures as a tool in Biomaterial Research
Journal of Materials Science: Materials in Medicine, 1999Co-Authors: C. J. Kirkpatrick, M. Otto, T. Van Kooten, V. Krump, J. Kriegsmann, F. BittingerAbstract:Progress in biocompatibility and tissue engineering would today be inconceivable without the aid of in vitro techniques. Endothelial cell cultures represent a valuable tool not just in haemocompatibility testing, but also in the concept of designing hybrid organs. In the past endothelial cells (EC) have frequently been used in cytotoxicity testing of materials, especially polymers, used in blood-contacting implants, as well as for investigating seeding technologies for vascular prostheses. At present the exponential development both in theory and practice of cell and molecular biology of the endothelium offers great promise in the Biomaterial field. Up until now this EC Research field has mostly been non-Biomaterial orientated. Nevertheless, the relevance for Biomaterial Research is apparent. Four aspects will be concisely reviewed under the headings inflammation, with special reference to cell adhesion molecules (CAMs) and cytokines, angiogenesis, focusing on the healing response, signal transduction, presenting examples from cytokine- and metal ion-induced up-regulation of genes coding for CAMs, and, finally, endothelial functionality, with emphasis on the principal characteristics of the physiological endothelial phenotype. Finally, the application of these fields to three foci of Biomaterial Research will be discussed, emphasizing the role of EC culture techniques in controlling the host response to Biomaterials (microvascular EC), controlling EC functionality (promoting positive effects and down-regulating negative effects), and tissue engineering (integration of EC into hybrid organs/biosensors). The need for more co-culture and three-dimensional models will be stressed and data from the authors’ laboratory presented to illustrate these principles. © 1999 Kluwer Academic Publishers
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The cell and molecular biological approach to Biomaterial Research: a perspective
Journal of Materials Science: Materials in Medicine, 1997Co-Authors: C. J. Kirkpatrick, M. Otto, F. Bittinger, M Wagner, H Kohler, C. L KleinAbstract:The past two decades have witnessed a revolution in our understanding of chemical processes in living organisms. This is mainly a result of the massive advances in the fields of cell and molecular biology. These techniques are highly relevant to the Biomaterials sector, as they offer the scientist the possibility to better understand the mechanisms involved in the interactions between cells and a material surface—a prerequisite for the rational development of medical devices with optimal biocompatibility. The purpose of the present article is to explain the rationale of the cell and molecular biological approach to Biomaterial Research and to present typical examples from the authors’ laboratory, as well as from the literature, to illustrate its application. Important aspects of interfacial biology, including the underlying biological mechanisms and methodology, are presented. Of the latter the combination of morphological techniques with methods of cell and molecular biology as well as molecular genetics (so-called “combinative techniques”) are particularly useful. The applicability of this approach is illustrated from a study on the pathomechanisms of metal ion-induced inflammation. In addition, the approach is essential to the development of targeted intervention strategies, as for example in the luminal surface modification of vascular prostheses to permit endothelial cell seeding.
Borys Bondar - One of the best experts on this subject based on the ideXlab platform.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. James KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-β1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-β1.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. J. KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-beta1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-beta1.
S G Pearce - One of the best experts on this subject based on the ideXlab platform.
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animal models for implant Biomaterial Research in bone a review
European Cells & Materials, 2007Co-Authors: A I Pearce, R G Richards, Stefan Milz, Erich Schneider, S G PearceAbstract:Development of an optimal interface between bone and orthopaedic or dental implants has taken place for many years. In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation. For this reason the use of animal models is often an essential step in the testing of orthopaedic and dental implants prior to clinical use in humans. This review discusses some of the more commonly available and frequently used animal models such as the dog, sheep, goat, pig and rabbit models for the evaluation of bone-implant interactions. Factors for consideration when choosing an animal model and implant design are discussed. Various bone specific features are discussed including the usage of the species, bone macrostructure and microstructure and bone composition and remodelling, with emphasis being placed on the similarity between the animal model and the human clinical situation. While the rabbit was the most commonly used of the species discussed in this review, it is clear that this species shows the least similarities to human bone. There were only minor differences in bone composition between the various species and humans. The pig demonstrates a good likeness with human bone, however difficulties may be encountered in relation to their size and ease of handling. In this respect the dog and sheep/ goat show more promise as animal models for the testing of bone implant materials. While no species fulfils all of the requirements of an ideal model, an understanding of the differences in bone architecture and remodelling will assist in the selection of a suitable model for a defined Research question.
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animal models for implant Biomaterial Research in bone a review
European Cells & Materials, 2007Co-Authors: A I Pearce, R G Richards, Stefan Milz, Erich Schneider, S G PearceAbstract:Development of an optimal interface between bone and orthopaedic and dental implants has taken place for many years. In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation. For this reason the use of animal models is often an essential step in the testing of orthopaedic and dental implants prior to clinical use in humans. This review discusses some of the more commonly available and frequently used animal models such as the dog, sheep, goat, pig and rabbit models for the evaluation of bone-implant interactions. Factors for consideration when choosing an animal model and implant design are discussed. Various bone specific features are discussed including the usage of the species, bone macrostructure and microstructure and bone composition and remodelling, with emphasis being placed on the similarity between the animal model and the human clinical situation. While the rabbit was the most commonly used of the species discussed in this review, it is clear that this species showed the least similarities to human bone. There were only minor differences in bone composition between the various species and humans. The pig demonstrated a good likeness with human bone however difficulties may be encountered in relation to their size and ease of handling. In this respect the dog and sheep/goat show more promise as animal models for the testing of bone implant materials. While no species fulfils all of the requirements of an ideal model, an understanding of the differences in bone architecture and remodelling between the species is likely to assist in the selection of a suitable species for a defined Research question.
C. James Kirkpatrick - One of the best experts on this subject based on the ideXlab platform.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. James KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-β1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-β1.
Claudio Migliaresi - One of the best experts on this subject based on the ideXlab platform.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. James KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-β1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-β1.
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functionality of endothelial cells on silk fibroin nets comparative study of micro and nanometric fibre size
Biomaterials, 2008Co-Authors: Borys Bondar, Antonella Motta, Sabine Fuchs, Claudio Migliaresi, C. J. KirkpatrickAbstract:Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for Biomaterial Research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified Biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellular morphology, proliferation, formation of intercellular contacts as well as integrin-dependent adhesion. Endothelial cells (ECs) grown on nanometric nets formed a differentiated and interconnected endothelial monolayer with no significant changes in the expression of intercellular contact molecules or proliferation rates compared with cells grown on micrometric nets. Nevertheless, quantitative real-time PCR revealed a higher expression level of integrin-beta1 in ECs grown on nanofibrous fibroin nets compared to the microfibrous samples. In addition, single nano-fibres were recognised by the integrin-receptor mechanism supporting the formation of focal adhesion at the interface of ECs and nanometric nets. These findings indicate that the nanometric silk fibroin scaffolds did not interfere with the formation of a differentiated and interconnected EC layer. On the contrary, nanofibre variation of the fibroin net architecture induced changes in ECs at the molecular level in terms of the increased expression of adhesion molecules such as integrin-beta1.