The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Weiliam Chen - One of the best experts on this subject based on the ideXlab platform.
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a fibroblast macrophage co culture model to evaluate the biocompatibility of an electrospun dextran plga scaffold and its potential to induce inflammatory responses
Biomedical Materials, 2011Co-Authors: Hui Pan, Hongliang Jiang, Sarah Kantharia, Weiliam ChenAbstract:Fibroblasts and macrophages are the two major types of cells responding to Implanted Biomaterials. They play crucial roles in inflammatory responses, host-material interactions and tissue remodeling. However, the synergistic interactions of these two cell types with Biomaterials are not fully understood. In this investigation, an in vitro fibroblast/macrophage co-culture system was utilized to examine the biocompatibility and the potential to induce inflammatory responses of an electrospun Dextran/PLGA scaffold. The scaffold did not affect the morphologies, attachments, proliferations and viabilities of both the fibroblasts and macrophages, cultured separately or together. Moreover, it only activated a small subset of the macrophages implicating a low potential to induce either severe acute or chronic inflammatory response. Additionally, fibroblasts played a role in prolonging macrophage activation in the presence of the scaffolds. Using antibody arrays, IL-10, SDF-1, MIP-1 gamma and RANTES were found to be up-regulated when the cells were incubated with the scaffolds. The results of subdermal implantation of the Dextran/PLGA scaffolds confirmed its biocompatibility and low inflammatory potential.
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the biodegradability of electrospun dextran plga scaffold in a fibroblast macrophage co culture
Biomaterials, 2008Co-Authors: Hui Pan, Hongliang Jiang, Weiliam ChenAbstract:Fibroblast and macrophage are 2 dominant cell types respond cooperatively to degrade Implanted Biomaterials. Using an electrospun Dextran/Poly-lactide-co-glycolide (PLGA) scaffold as a model, an in vitro fibroblast/macrophage co-culture system was developed to investigate the degradability of implantable biodegradable materials. SEM showed that both fibroblasts and macrophages were able to degrade the scaffold, separately or cooperatively. Under the synergistic coordination of macrophages and fibroblasts, scaffolds showed faster degradation rate than their counterparts incubated with a single type of cells as well as in PBS or cell culture medium. Lysozyme, non-specific esterase (NSE), gelatinase, hyaluronidase-1 and α-glucosidase were up-regulated in the presence of the scaffold, suggesting their roles in the cell-mediated scaffold degradation. In addition, the expressions of cell surface receptors CD204 and Toll like receptor 4 (TLR4) were elevated 1 week after cell seeding, implying that these receptors might be involved in scaffold degradation. The results of in vivo subdermal implantation of the scaffold further confirmed the biodegradability of the Dextran/PLGA scaffold. The fibroblast/macrophage co-culture model adequately mimicked the in vivo environment and could be further developed into an in vitro tool for initial biomaterial evaluation.
Hui Pan - One of the best experts on this subject based on the ideXlab platform.
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a fibroblast macrophage co culture model to evaluate the biocompatibility of an electrospun dextran plga scaffold and its potential to induce inflammatory responses
Biomedical Materials, 2011Co-Authors: Hui Pan, Hongliang Jiang, Sarah Kantharia, Weiliam ChenAbstract:Fibroblasts and macrophages are the two major types of cells responding to Implanted Biomaterials. They play crucial roles in inflammatory responses, host-material interactions and tissue remodeling. However, the synergistic interactions of these two cell types with Biomaterials are not fully understood. In this investigation, an in vitro fibroblast/macrophage co-culture system was utilized to examine the biocompatibility and the potential to induce inflammatory responses of an electrospun Dextran/PLGA scaffold. The scaffold did not affect the morphologies, attachments, proliferations and viabilities of both the fibroblasts and macrophages, cultured separately or together. Moreover, it only activated a small subset of the macrophages implicating a low potential to induce either severe acute or chronic inflammatory response. Additionally, fibroblasts played a role in prolonging macrophage activation in the presence of the scaffolds. Using antibody arrays, IL-10, SDF-1, MIP-1 gamma and RANTES were found to be up-regulated when the cells were incubated with the scaffolds. The results of subdermal implantation of the Dextran/PLGA scaffolds confirmed its biocompatibility and low inflammatory potential.
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the biodegradability of electrospun dextran plga scaffold in a fibroblast macrophage co culture
Biomaterials, 2008Co-Authors: Hui Pan, Hongliang Jiang, Weiliam ChenAbstract:Fibroblast and macrophage are 2 dominant cell types respond cooperatively to degrade Implanted Biomaterials. Using an electrospun Dextran/Poly-lactide-co-glycolide (PLGA) scaffold as a model, an in vitro fibroblast/macrophage co-culture system was developed to investigate the degradability of implantable biodegradable materials. SEM showed that both fibroblasts and macrophages were able to degrade the scaffold, separately or cooperatively. Under the synergistic coordination of macrophages and fibroblasts, scaffolds showed faster degradation rate than their counterparts incubated with a single type of cells as well as in PBS or cell culture medium. Lysozyme, non-specific esterase (NSE), gelatinase, hyaluronidase-1 and α-glucosidase were up-regulated in the presence of the scaffold, suggesting their roles in the cell-mediated scaffold degradation. In addition, the expressions of cell surface receptors CD204 and Toll like receptor 4 (TLR4) were elevated 1 week after cell seeding, implying that these receptors might be involved in scaffold degradation. The results of in vivo subdermal implantation of the scaffold further confirmed the biodegradability of the Dextran/PLGA scaffold. The fibroblast/macrophage co-culture model adequately mimicked the in vivo environment and could be further developed into an in vitro tool for initial biomaterial evaluation.
K Fritz - One of the best experts on this subject based on the ideXlab platform.
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consensus statement on prevention and management of adverse effects following rejuvenation procedures with hyaluronic acid based fillers
Journal of The European Academy of Dermatology and Venereology, 2017Co-Authors: Wolfgang G Philippdormston, D Bergfeld, Boris Sommer, G Sattler, S Cotofana, P Snozzi, Uwe Wollina, K P J Hoffmann, Carmen Maria Salavastru, K FritzAbstract:Facial fillers play an important role in the correction of facial changes associated with ageing. They offer quick treatments in the outpatient setting with minimal subsequent downtime that provide predictable, natural-looking, long-lasting results. Adverse reactions after hyaluronic acid injections tend to be mild or moderate and rather temporary. However, as with all injected or Implanted Biomaterials, severe adverse events can occur and patients must be fully informed of potential risks prior to undergoing treatment. A panel of experts from Germany (D), Austria (A) and Switzerland (CH) developed recommendations, and this study provides the 'DACH Consensus Recommendations' from this group specifically on the use of hyaluronic acid fillers. The aim is to help clinicians recognize potential risks and to provide guidance on how best to treat adverse events if they arise. Contraindications to hyaluronic acid fillers are also detailed, and ways to prevent adverse events occurring are discussed. Hyaluronic acid-based products are claimed to be very close to an ideal tissue augmentation agent; nevertheless, profound medical, anatomical and product knowledge are of paramount importance to minimize the occurrence of adverse reactions.
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consensus statement on prevention and management of adverse effects following rejuvenation procedures with hyaluronic acid based fillers
Journal of The European Academy of Dermatology and Venereology, 2017Co-Authors: Wolfgang G Philippdormston, D Bergfeld, Boris Sommer, G Sattler, S Cotofana, P Snozzi, Uwe Wollina, Carmen Maria Salavastru, K Hoffmann, K FritzAbstract:Facial fillers play an important role in the correction of facial changes associated with ageing. They offer quick treatments in the outpatient setting with minimal subsequent downtime that provide predictable, natural-looking, long-lasting results. Hyaluronic acid soft tissue injectables have established their role as the fillers of choice for patients over the last 2 decades. Hyaluronic acid fillers are rarely associated with adverse reactions, and those that do occur tend to be mild and temporary. However, as with all injected or Implanted Biomaterials, adverse events can occur and patients must be fully informed of potential risks prior to undergoing treatment. A panel of experts from Germany (D), Austria (A) and Switzerland (CH) developed recommendations and this paper provides the ‘DACH Consensus Recommendations’ from this group specifically on the use of hyaluronic acid fillers. The aim is to help clinicians recognise potential risks and to provide guidance on how best to treat adverse events if they arise. Contra-indications to hyaluronic acid fillers are also detailed and ways to prevent adverse events occurring are discussed. Hyaluronic acid-based products are claimed by some to be very close to fulfilling many of the requirements of an ideal tissue augmentation agent, nevertheless, the potential benefits of treatment must be carefully weighed against the risk of potential adverse events. This article is protected by copyright. All rights reserved.
Hongliang Jiang - One of the best experts on this subject based on the ideXlab platform.
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a fibroblast macrophage co culture model to evaluate the biocompatibility of an electrospun dextran plga scaffold and its potential to induce inflammatory responses
Biomedical Materials, 2011Co-Authors: Hui Pan, Hongliang Jiang, Sarah Kantharia, Weiliam ChenAbstract:Fibroblasts and macrophages are the two major types of cells responding to Implanted Biomaterials. They play crucial roles in inflammatory responses, host-material interactions and tissue remodeling. However, the synergistic interactions of these two cell types with Biomaterials are not fully understood. In this investigation, an in vitro fibroblast/macrophage co-culture system was utilized to examine the biocompatibility and the potential to induce inflammatory responses of an electrospun Dextran/PLGA scaffold. The scaffold did not affect the morphologies, attachments, proliferations and viabilities of both the fibroblasts and macrophages, cultured separately or together. Moreover, it only activated a small subset of the macrophages implicating a low potential to induce either severe acute or chronic inflammatory response. Additionally, fibroblasts played a role in prolonging macrophage activation in the presence of the scaffolds. Using antibody arrays, IL-10, SDF-1, MIP-1 gamma and RANTES were found to be up-regulated when the cells were incubated with the scaffolds. The results of subdermal implantation of the Dextran/PLGA scaffolds confirmed its biocompatibility and low inflammatory potential.
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the biodegradability of electrospun dextran plga scaffold in a fibroblast macrophage co culture
Biomaterials, 2008Co-Authors: Hui Pan, Hongliang Jiang, Weiliam ChenAbstract:Fibroblast and macrophage are 2 dominant cell types respond cooperatively to degrade Implanted Biomaterials. Using an electrospun Dextran/Poly-lactide-co-glycolide (PLGA) scaffold as a model, an in vitro fibroblast/macrophage co-culture system was developed to investigate the degradability of implantable biodegradable materials. SEM showed that both fibroblasts and macrophages were able to degrade the scaffold, separately or cooperatively. Under the synergistic coordination of macrophages and fibroblasts, scaffolds showed faster degradation rate than their counterparts incubated with a single type of cells as well as in PBS or cell culture medium. Lysozyme, non-specific esterase (NSE), gelatinase, hyaluronidase-1 and α-glucosidase were up-regulated in the presence of the scaffold, suggesting their roles in the cell-mediated scaffold degradation. In addition, the expressions of cell surface receptors CD204 and Toll like receptor 4 (TLR4) were elevated 1 week after cell seeding, implying that these receptors might be involved in scaffold degradation. The results of in vivo subdermal implantation of the scaffold further confirmed the biodegradability of the Dextran/PLGA scaffold. The fibroblast/macrophage co-culture model adequately mimicked the in vivo environment and could be further developed into an in vitro tool for initial biomaterial evaluation.
Liping Tang - One of the best experts on this subject based on the ideXlab platform.
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molecular basis of biomaterial mediated foreign body reactions
Blood, 2001Co-Authors: Wenjing Hu, Tatiana P Ugarova, John W. Eaton, Liping TangAbstract:Despite being inert and nontoxic, Implanted Biomaterials often trigger adverse foreign body reactions such as inflammation, fibrosis, infection, and thrombosis. With regard to the inflammatory responses to biomaterial implants, it was previously found that a crucial precedent event was the spontaneous adsorption and denaturation of fibrinogen on implant surfaces. It was further found that interactions between the phagocyte integrin Mac-1 (CD11b/CD18) and one short sequence within the fibrinogen D domain (γ190-202; P1) at least partially explained phagocyte accumulation on implant surfaces. However, the reason that adsorbed fibrinogen is proinflammatory—while soluble fibrinogen clearly is not—remained obscure. In this study, therefore, the question of how fibrinogen is converted to a proinflammatory state when adsorbed to biomaterial surfaces is investigated. In soluble fibrinogen, the 13 amino acid P1 sequence was found to be hidden. However, the adsorption and denaturation of fibrinogen on the surfaces of commonly used Biomaterials lead to the exposure of P1 and a second neo-epitope, γ377-395 (P2), which also interacts with Mac-1 and is similarly occult in the soluble protein. The extent of biomaterial-mediated P1 and P2 exposure appears directly related to the severity of inflammatory responses to a test panel of Biomaterials. Finally, thrombin-mediated conversion of fibrinogen to fibrin also exposes both P1 and P2 epitopes. These observations may help explain both the inflammation caused by many types of Implanted Biomaterials and that which occurs naturally following thrombotic events.
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mast cells mediate acute inflammatory responses to Implanted Biomaterials
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Liping Tang, Timothy A Jennings, John W. EatonAbstract:Implanted Biomaterials trigger acute and chronic inflammatory responses. The mechanisms involved in such acute inflammatory responses can be arbitrarily divided into phagocyte transmigration, chemotaxis, and adhesion to implant surfaces. We earlier observed that two chemokines-macrophage inflammatory protein 1alpha/monocyte chemoattractant protein 1-and the phagocyte integrin Mac-1 (CD11b/CD18)/surface fibrinogen interaction are, respectively, required for phagocyte chemotaxis and adherence to biomaterial surfaces. However, it is still not clear how the initial transmigration of phagocytes through the endothelial barrier into the area of the implant is triggered. Because Implanted Biomaterials elicit histaminic responses in the surrounding tissue, and histamine release is known to promote rapid diapedesis of inflammatory cells, we evaluated the possible role of histamine and mast cells in the recruitment of phagocytes to biomaterial implants. Using i.p. and s. c. implantation of polyethylene terephthalate disks in mice we find: (i) Extensive degranulation of mast cells, accompanied by histamine release, occurs adjacent to short-term i.p. implants. (ii) Simultaneous administration of H1 and H2 histamine receptor antagonists (pyrilamine and famotidine, respectively) greatly diminishes recruitment and adhesion of both neutrophils (<20% of control) and monocytes/macrophages (<30% of control) to implants. (iii) Congenitally mast cell-deficient mice also exhibit markedly reduced accumulation of phagocytes on both i.p. and s.c implants. (iv) Finally, mast cell reconstitution of mast cell-deficient mice restores "normal" inflammatory responses to biomaterial implants. We conclude that mast cells and their granular products, especially histamine, are important in recruitment of inflammatory cells to biomaterial implants. Improved knowledge of such responses may permit purposeful modulation of both acute and chronic inflammation affecting Implanted Biomaterials.
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mast cells mediate acute inflammatory responses to Implanted Biomaterials histamineyphagocytes
1998Co-Authors: Liping Tang, Imothy T A Jennings, John W. EatonAbstract:Implanted Biomaterials trigger acute and chronic inf lammatory responses. The mechanisms involved in such acute inf lammatory responses can be arbitrarily divided into phagocyte transmigration, chemotaxis, and adhesion to implant surfaces. We earlier observed that two chemokines— macrophage inf lammatory protein 1aymonocyte chemoat- tractant protein 1—and the phagocyte integrin Mac-1 (CD11byCD18)ysurface fibrinogen interaction are, respec- tively, required for phagocyte chemotaxis and adherence to biomaterial surfaces. However, it is still not clear how the initial transmigration of phagocytes through the endothelial barrier into the area of the implant is triggered. Because Implanted Biomaterials elicit histaminic responses in the surrounding tissue, and histamine release is known to pro- mote rapid diapedesis of inf lammatory cells, we evaluated the possible role of histamine and mast cells in the recruitment of phagocytes to biomaterial implants. Using i.p. and s.c. im- plantation of polyethylene terephthalate disks in mice we find: (i) Extensive degranulation of mast cells, accompanied by histamine release, occurs adjacent to short-term i.p. implants. (ii) Simultaneous administration of H1 and H2 histamine receptor antagonists (pyrilamine and famotidine, respec- tively) greatly diminishes recruitment and adhesion of both neutrophils (<20% of control) and monocytesymacrophages (<30% of control) to implants. (iii) Congenitally mast cell- deficient mice also exhibit markedly reduced accumulation of phagocytes on both i.p. and s.c implants. (iv) Finally, mast cell reconstitution of mast cell-deficient mice restores ''normal'' inf lammatory responses to biomaterial implants. We con- clude that mast cells and their granular products, especially histamine, are important in recruitment of inf lammatory cells to biomaterial implants. Improved knowledge of such re- sponses may permit purposeful modulation of both acute and chronic inf lammation affecting Implanted Biomaterials.
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Inflammatory responses to Implanted polymeric Biomaterials: role of surface-adsorbed immunoglobulin G.
The Journal of laboratory and clinical medicine, 1993Co-Authors: Liping Tang, Alexander H. Lucas, John W. EatonAbstract:In many cases, evidently inert and nontoxic Biomaterials may trigger procoagulant and inflammatory responses. Because most polymeric Biomaterials accumulate a surface layer of protein immediately after implantation, these adverse reactions may stem from secondary interactions between the host and this surface layer of adsorbed proteins. Using polyester terephthalate (the polymer from which both Dacron and Mylar are produced) as a model, we have explored the hypothesis that surface-adsorbed immunoglobulin might mediate subsequent inflammatory responses. We find, as have others, that immunoglobulin G (IgG) does spontaneously adsorb to polymer surfaces, both in vitro and in vivo. Furthermore, polymer implants precoated with IgG do activate human polymorphonuclear neutrophils in vitro and also attract substantial numbers of phagocytes (especially polymorphonuclear neutrophils and macrophages) when Implanted in mice. However, when implants are placed in mice having a form of severe combined immunodeficiency (and, consequently, almost undetectable levels of serum IgG), a near-normal influx of phagocytic cells ensues. Thus, spontaneously-adsorbed surface IgG does not appear to be a necessary precedent to inflammatory responses directed against Implanted Biomaterials.
