The Experts below are selected from a list of 39516 Experts worldwide ranked by ideXlab platform
Geris Liesbet - One of the best experts on this subject based on the ideXlab platform.
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Combining microCT-based characterization with empirical modelling as a robust screening approach for the design of optimized CaP-containing scaffolds for progenitor Cell-mediated bone formation
Elsevier, 2016Co-Authors: Kerckhofs Greet, Chai Y C, Luyten F P, Geris LiesbetAbstract:Biomaterials are a key ingredient to the success of bone tissue engineering (TE), which focuses on the healing of bone defects by combining scaffolds with Cells and/or growth factors. Due to the widely variable material characteristics and patient-specificities, however, current bone TE strategies still suffer from low repeatability and lack of robustness, which hamper clinical translation. Hence, optimal TE construct (i.e. Cells and scaffold) characteristics are still under debate. This study aimed to reduce the material-specific variability for Cell-based construct design, avoiding trial-and-error, by combining microCT characterization and empirical modelling as an innovative and robust screening approach. Via microCT characterization we have built a quantitative construct library of morphological and compositional properties of six CE approved CaP-based scaffolds (CopiOs(®), BioOss™, Integra Mozaik™, chronOS Vivify, MBCP™ and ReproBone™), and of their bone forming capacity and in vivo scaffold degradation when combined with human periosteal derived Cells (hPDCs). The empirical model, based on the construct library, allowed identification of the construct characteristics driving optimized bone formation, i.e. (a) the percentage of β-TCP and dibasic calcium phosphate, (b) the concavity of the CaP structure, (c) the average CaP structure thickness and (d) the Seeded Cell amount (taking into account the seeding efficiency). Additionally, the model allowed to quantitatively predict the bone forming response of different hPDC-CaP scaffold combinations, thus providing input for a more robust design of optimized constructs and avoiding trial-and error. This could improve and facilitate clinical translation.status: publishe
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Combining microCT-based characterization with empirical modelling as a robust screening approach for the design of optimized CaP-containing scaffolds for progenitor Cell-mediated bone formation
'Elsevier BV', 2016Co-Authors: Kerckhofs Greet, Yc Chai, Fp Luyten, Geris LiesbetAbstract:Biomaterials are a key ingredient to the success of bone tissue engineering (TE), which focuses on the healing of bone defects by combining scaffolds with Cells and/or growth factors. Due to the widely variable material characteristics and patient-specificities, however, current bone TE strategies still suffer from low repeatability and lack of robustness, which hamper clinical translation. Hence, optimal TE construct (i.e. Cells and scaffold) characteristics are still under debate. This study aimed to reduce the material-specific variability for Cell-based construct design, avoiding trial-and-error, by combining microCT characterization and empirical modelling as an innovative and robust screening approach. Via microCT characterization we have built a quantitative construct library of morphological and compositional properties of six CE approved CaP-based scaffolds (CopiOs(®), BioOss™, Integra Mozaik™, chronOS Vivify, MBCP™ and ReproBone™), and of their bone forming capacity and in vivo scaffold degradation when combined with human periosteal derived Cells (hPDCs). The empirical model, based on the construct library, allowed identification of the construct characteristics driving optimized bone formation, i.e. (a) the percentage of β-TCP and dibasic calcium phosphate, (b) the concavity of the CaP structure, (c) the average CaP structure thickness and (d) the Seeded Cell amount (taking into account the seeding efficiency). Additionally, the model allowed to quantitatively predict the bone forming response of different hPDC-CaP scaffold combinations, thus providing input for a more robust design of optimized constructs and avoiding trial-and error. This could improve and facilitate clinical translation.publisher: Elsevier articletitle: Combining microCT-based characterization with empirical modelling as a robust screening approach for the design of optimized CaP-containing scaffolds for progenitor Cell-mediated bone formation journaltitle: Acta Biomaterialia articlelink: http://dx.doi.org/10.1016/j.actbio.2016.02.037 content_type: article copyright: Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.status: publishe
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Combining microCT-based characterization with empirical modelling as a robust screening approach for the design of optimized CaP-containing scaffolds for progenitor Cell-mediated bone formation.
'Elsevier BV', 2016Co-Authors: Kerckhofs G., Chai Y C, Luyten F P, Geris LiesbetAbstract:peer reviewedBiomaterials are a key ingredient to the success of bone tissue engineering (TE), which focuses on the healing of bone defects by combining scaffolds with Cells and/or growth factors. Due to the widely variable material characteristics and patient-specificities, however, current bone TE strategies still suffer from low repeatability and lack of robustness, which hamper clinical translation. Hence, optimal TE construct (i.e. Cells and scaffold) characteristics are still under debate. This study aimed to reduce the material-specific variability for Cell-based construct design, avoiding trial-and-error, by combining microCT characterization and empirical modelling as an innovative and robust screening approach. Via microCT characterization we have built a quantitative construct library of morphological and compositional properties of six CE approved CaP-based scaffolds (CopiOs(R), BioOss, Integra Mozaik, chronOS Vivify, MBCP and ReproBone), and of their bone forming capacity and in vivo scaffold degradation when combined with human periosteal derived Cells (hPDCs). The empirical model, based on the construct library, allowed identification of the construct characteristics driving optimized bone formation, i.e. (a) the percentage of beta-TCP and dibasic calcium phosphate, (b) the concavity of the CaP structure, (c) the average CaP structure thickness and (d) the Seeded Cell amount (taking into account the seeding efficiency). Additionally, the model allowed to quantitatively predict the bone forming response of different hPDC-CaP scaffold combinations, thus providing input for a more robust design of optimized constructs and avoiding trial-and error. This could improve and facilitate clinical translation. STATEMENT OF SIGNIFICANCE: Biomaterials that support regenerative processes are a key ingredient for successful bone tissue engineering (TE). However, the optimal scaffold structure is still under debate. In this study, we have provided a useful innovative approach for robust screening of potential biomaterials or constructs (i.e. scaffolds Seeded with Cells and/or growth factors) by combining microCT characterization with empirical modelling. This novel approach leads to a better insight in the scaffold parameters influencing progenitor Cell-mediated bone formation. Additionally, it serves as input for more controlled and robust design of optimized CaP-containing bone TE scaffolds. Hence, this novel approach could improve and facilitate clinical translation
Nilsclaudius Gellrich - One of the best experts on this subject based on the ideXlab platform.
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consequences of Seeded Cell type on vascularization of tissue engineering constructs in vivo
Microvascular Research, 2009Co-Authors: Paul Schumann, Frank Tavassol, Daniel Lindhorst, Constantin Stuehmer, Kaihendrik Bormann, Andreas Kampmann, Rolf Mulhaupt, Matthias W Laschke, Michael D Menger, Nilsclaudius GellrichAbstract:Implantation of tissue engineering constructs is a promising technique to reconstruct injured tissue. However, after implantation the nutrition of the constructs is predominantly restricted to vascularization. Since Cells possess distinct angiogenic potency, we herein assessed whether scaffold vitalization with different Cell types improves scaffold vascularization. 32 male balb/c mice received a dorsal skinfold chamber. Angiogenesis, microhemodynamics, leukocyte-endothelial Cell interaction and microvascular permeability induced in the host tissue after implantation of either collagen coated poly (L-lactide-co-glycolide) (PLGA) scaffolds (group 4), additionally Seeded with osteoblast-like Cells (OLCs, group 1), bone marrow mesenchymal stem Cells (bmMSCs, group 2) or a combination of OLCs and bmMSCs (group 3) were analyzed repetitively over 14 days using intravital fluorescence microscopy. Apart from a weak inflammatory response in all groups, vascularization was found distinctly accelerated in vitalized scaffolds, indicated by a significantly increased microvascular density (day 6, group 1: 202+/-15 cm/cm(2), group 2: 202+/-12 cm/cm(2), group 3: 194+/-8 cm/cm(2)), when compared with controls (group 4: 72+/-5 cm/cm(2)). This acceleration was independent from the Seeded Cell type. Immunohistochemistry revealed in vivo VEGF expression in close vicinity to the Seeded OLCs and bmMSCs. Therefore, the observed lack of Cell type confined differences in the vascularization process suggests that the accelerated vascularization of vitalized scaffolds is VEGF-related rather than dependent on the potential of bmMSCs to differentiate into specific vascular Cells.
Yuquan Zhou - One of the best experts on this subject based on the ideXlab platform.
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evaluation of hygroscopic cloud seeding in liquid water clouds a feasibility study
Atmospheric Chemistry and Physics, 2019Co-Authors: Fei Wang, Qi Jiang, Gaili Wang, Shuo Jia, Jing Duan, Yuquan ZhouAbstract:Abstract. An airborne cloud seeding experiment was conducted over the eastern coast of Zhejiang, China, on 4 September 2016 during a major international event held in Hangzhou. In an attempt to reduce the likelihood of rainfall onset, a major airborne experiment for weather modification took place by seeding hygroscopic agents to warm clouds to reduce cloud droplet size. The effectiveness of seeding is examined, mainly for stratiform clouds with patchy small convective Cells. A radar-domain-index (RDI) algorithm was proposed to analyze the seeding effect. The threshold strategy and the tracking radar echo by correlation (TREC) technique was applied in the domain selection. Factors analyzed include echo reflectivity parameters such as the mean and maximum echo intensity, the anomaly percentage of the grid number of effective echoes, the fractional contribution to the total reflectivities, and the vertically integrated liquid (VIL) water content during and after the seeding process. About 12 min after seeding ended, the composite reflectivity of Seeded clouds decreased to a minimum ( ∼0.2 kg m −3 . The echo top height dropped to ∼3.5 km, and the surface echoes were also weakened. By contrast, there was no significant variation in these echo parameters for the surrounding non-Seeded clouds. The Seeded Cell appeared to have the shortest life cycle, as revealed by applying the cloud-cluster tracking method. The airborne Cloud Droplet Probe (CDP) measured cloud number concentration, effective diameter, and liquid water content, which gradually increased after the start of cloud seeding. This is probably caused by the hygroscopic growth of agent particles and collision–coalescence of small cloud droplets. However, these parameters sampled at ∼40 min after seeding decreased significantly, which is probably due to the excessive seeding agents generating a competition for cloud water and thus suppressing cloud development and precipitation. Overall, the physical phenomenon was captured in this study, but a more quantitative in-depth analysis of the underlying principle is needed.
Paul Schumann - One of the best experts on this subject based on the ideXlab platform.
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consequences of Seeded Cell type on vascularization of tissue engineering constructs in vivo
Microvascular Research, 2009Co-Authors: Paul Schumann, Frank Tavassol, Daniel Lindhorst, Constantin Stuehmer, Kaihendrik Bormann, Andreas Kampmann, Rolf Mulhaupt, Matthias W Laschke, Michael D Menger, Nilsclaudius GellrichAbstract:Implantation of tissue engineering constructs is a promising technique to reconstruct injured tissue. However, after implantation the nutrition of the constructs is predominantly restricted to vascularization. Since Cells possess distinct angiogenic potency, we herein assessed whether scaffold vitalization with different Cell types improves scaffold vascularization. 32 male balb/c mice received a dorsal skinfold chamber. Angiogenesis, microhemodynamics, leukocyte-endothelial Cell interaction and microvascular permeability induced in the host tissue after implantation of either collagen coated poly (L-lactide-co-glycolide) (PLGA) scaffolds (group 4), additionally Seeded with osteoblast-like Cells (OLCs, group 1), bone marrow mesenchymal stem Cells (bmMSCs, group 2) or a combination of OLCs and bmMSCs (group 3) were analyzed repetitively over 14 days using intravital fluorescence microscopy. Apart from a weak inflammatory response in all groups, vascularization was found distinctly accelerated in vitalized scaffolds, indicated by a significantly increased microvascular density (day 6, group 1: 202+/-15 cm/cm(2), group 2: 202+/-12 cm/cm(2), group 3: 194+/-8 cm/cm(2)), when compared with controls (group 4: 72+/-5 cm/cm(2)). This acceleration was independent from the Seeded Cell type. Immunohistochemistry revealed in vivo VEGF expression in close vicinity to the Seeded OLCs and bmMSCs. Therefore, the observed lack of Cell type confined differences in the vascularization process suggests that the accelerated vascularization of vitalized scaffolds is VEGF-related rather than dependent on the potential of bmMSCs to differentiate into specific vascular Cells.
Fei Wang - One of the best experts on this subject based on the ideXlab platform.
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evaluation of hygroscopic cloud seeding in liquid water clouds a feasibility study
Atmospheric Chemistry and Physics, 2019Co-Authors: Fei Wang, Qi Jiang, Gaili Wang, Shuo Jia, Jing Duan, Yuquan ZhouAbstract:Abstract. An airborne cloud seeding experiment was conducted over the eastern coast of Zhejiang, China, on 4 September 2016 during a major international event held in Hangzhou. In an attempt to reduce the likelihood of rainfall onset, a major airborne experiment for weather modification took place by seeding hygroscopic agents to warm clouds to reduce cloud droplet size. The effectiveness of seeding is examined, mainly for stratiform clouds with patchy small convective Cells. A radar-domain-index (RDI) algorithm was proposed to analyze the seeding effect. The threshold strategy and the tracking radar echo by correlation (TREC) technique was applied in the domain selection. Factors analyzed include echo reflectivity parameters such as the mean and maximum echo intensity, the anomaly percentage of the grid number of effective echoes, the fractional contribution to the total reflectivities, and the vertically integrated liquid (VIL) water content during and after the seeding process. About 12 min after seeding ended, the composite reflectivity of Seeded clouds decreased to a minimum ( ∼0.2 kg m −3 . The echo top height dropped to ∼3.5 km, and the surface echoes were also weakened. By contrast, there was no significant variation in these echo parameters for the surrounding non-Seeded clouds. The Seeded Cell appeared to have the shortest life cycle, as revealed by applying the cloud-cluster tracking method. The airborne Cloud Droplet Probe (CDP) measured cloud number concentration, effective diameter, and liquid water content, which gradually increased after the start of cloud seeding. This is probably caused by the hygroscopic growth of agent particles and collision–coalescence of small cloud droplets. However, these parameters sampled at ∼40 min after seeding decreased significantly, which is probably due to the excessive seeding agents generating a competition for cloud water and thus suppressing cloud development and precipitation. Overall, the physical phenomenon was captured in this study, but a more quantitative in-depth analysis of the underlying principle is needed.