High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize th... more High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging. Diabetes Mellitus (DM) affects 56.3 million individuals in Europe and about 387 million worldwide (http://www. idf.org/). The current pandemic of the most common type of diabetes, type 2 diabetes (T2DM), largely results from a lifestyle with low physical activity and a high caloric diet leading to obesity. Obesity-induced T2DM is characterized by a progressive development of insulin resistance in liver and peripheral tissues accompanied by a defective insulin secretion from pancreatic beta cells leading to overt hyperglycaemia. Chronic hyperglycaemia results in microvascular complications (diabetic nephropathy, neuropathy, and retinopathy) as well as macrovas-cular morbidity (coronary artery disease, peripheral arterial disease, and stroke) and ultimately increased mortality 1. Substantial progress in diabetes monitoring and treatment has significantly increased the life expectancy of patients. As patients live longer, other comorbidities related to the diabetic condition have emerged, including a compromised skeletal health 2. Indeed, obese patients with T2DM experienced a 40 to 70% increased fracture risk despite a paradoxal normal to relatively high bone mineral density (BMD) compared to control subjects 3–6. These
Biomaterials are a key ingredient to the success of bone tissue engineering (TE), which focuses o... more 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.
Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foam... more Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foaming agent. Their porous structure was characterized through helium and mercury pyonometry, scanning electron microscopy (SEM) and X-ray microtomography observations coupled with image analysis. The pore size distributions obtained by these two latter techniques show that the pore structure is more homogeneous when the foaming process is
Aim X-ray microfocus computed tomography (µCT) is a very powerful technique for the characterisat... more Aim X-ray microfocus computed tomography (µCT) is a very powerful technique for the characterisation of the internal structure of materials in a quantitative and non-destructive way [1-5]. Many different µCT devices have been developed increasing the possibilities and applications for µCT-based analysis [6-11]. Recently, SkyScan NV [Kontich, Belgium] has developed an X-ray CT device to be installed in a scanning electron microscope (SEM), in the following referred to as the SEM-CT, which allows to investigate in the same device both the internal structure of materials in three dimensions down to the submicron level and the sample's surface topography [11]. The aim of this study is to investigate the capabilities and limitations of the SEM-CT system for materials research. Since the µCT-device is installed into a SEM, not only the target material of the SEM-CT device and the sample dimensions and morphology will influence the image quality, like in a normal µCT system, but also t...
Aims Main aim of this study was to determine the correlation between in-vitro cell behaviour and ... more Aims Main aim of this study was to determine the correlation between in-vitro cell behaviour and the strut surface roughness of Ti6Al4V scaffolds analysed based on micro-CT images. As the surface roughness determines the microscale morphology of the scaffold in quantitative way [1-4], appropriate surface topology analysis of the 3D porous structures is needed. Since commercially available profile measuring systems fail when determining the SSR of advanced porous structures, and because a high surface roughness of the struts compared to their dimensions causes difficulties for the quantitative determination of the surface morphology, a novel protocol for quantitative analysis of the surface morphology based on high resolution micro-CT images was used [4,5]. In-vitro biological experiment, with human periosteum derived cells (hPDCs) has been performed in order to analyse response of the osteogenic cells to different surface topologies of 3D scaffolds. Method Open porous bone scaffolds...
In order to understand and to simulate the functional behaviour of porous structures during loadi... more In order to understand and to simulate the functional behaviour of porous structures during loading, quantitative knowledge of the relationship between the morphology and the mechanical behaviour is necessary. Therefore, the porous structures need to be quantified morphologically. In this research, the quantification will be performed by using micro-CT. However, to date, this technique encounters some problems. Optimal acquisition parameters
To introduce a multimodular combination of techniques as a novel minimal invasive approach to inv... more To introduce a multimodular combination of techniques as a novel minimal invasive approach to investigate efficiently and accurately external cervical resorption (ECR). One case of a central incisor with extensive external cervical resorption was selected to demonstrate the potential of a comparative novel study methodology. ECR diagnosis was based on clinical inspection, digital radiography and cone-beam computed tomography (CBCT). After extraction the tooth was investigated using micro-focus computed tomography (micro-CT), nano-CT and hard tissue histology. These techniques were compared for their accuracy and applicability to highlight their advantages and disadvantages. Nano-CT was more effective than micro-CT and CBCT for detailed ex vivo exploration of ECR. The reparative tissue, pericanalar resorption resistant sheet (PRRS), pulp tissue reactions, resorption channels and their interconnection with the periodontal ligament space, were accurately visualised by detailed processi...
Om de relaties tussen de morfologie en de functionele eigenschappen van poreuze structuren te beg... more Om de relaties tussen de morfologie en de functionele eigenschappen van poreuze structuren te begrijpen en via eindige elementen te simuleren, om de uiteindelijke, bruikbare eigenschappen te relateren aan de productie en het bewerken van deze materialen, en om kennis te vergaren over de relatie tussen de morfologie en de mechanische eigenschappen enerzijds en het falingsgedrag anderzijds, zijn geschikte karakteriseringstechnieken nodig. X‑stralen microfocus computer tomografie (micro-CT) is een bruikbare oplossing, aangezien deze beeldvormingstechniek de mogelijkheid biedt om op een niet-destructieve manier een volledige 3D set van beelden te genereren die de interne architectuur visualiseren van de poreuze structuur op een microscopische schaal. Daarenboven laten de micro‑CT beelden een grondige beeldanalyse toe, wat resulteert in een uitgebreide, driedimensionale en kwantitatieve beschrijving van de morfologie van poreuze materialen; iets wat niet kan bereikt worden met andere kar...
We describe a non-destructive imaging method, named contrast-enhanced nanofocus X-ray computed to... more We describe a non-destructive imaging method, named contrast-enhanced nanofocus X-ray computed tomography (CE-nanoCT), that permits simultaneously imaging and quantifying in 3D the (sub)tissue architecture and (biochemical) composition of cartilage and bone in small animal models at a novel contrast and spatial resolution. To demonstrate the potential of this novel methodology, a newborn mouse was scanned using CE-nanoCT. This allowed simultaneously visualising the bone and cartilage structure much like the traditional alcian blue-alizarin red skeletal stain. Additionally, it enabled a 3D visualisation at such a high spatial image resolution that internal, micro-scale structures could be digitally dissected and evaluated for size, structure and composition. Ex vivo treatment with papain, that is known to specifically remove the non-calcified cartilage layer but keep the calcified cartilage intact, proved CE-nanoCT to be applicable to visualise the subdivisions within the hyaline car...
High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize th... more High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging. Diabetes Mellitus (DM) affects 56.3 million individuals in Europe and about 387 million worldwide (http://www. idf.org/). The current pandemic of the most common type of diabetes, type 2 diabetes (T2DM), largely results from a lifestyle with low physical activity and a high caloric diet leading to obesity. Obesity-induced T2DM is characterized by a progressive development of insulin resistance in liver and peripheral tissues accompanied by a defective insulin secretion from pancreatic beta cells leading to overt hyperglycaemia. Chronic hyperglycaemia results in microvascular complications (diabetic nephropathy, neuropathy, and retinopathy) as well as macrovas-cular morbidity (coronary artery disease, peripheral arterial disease, and stroke) and ultimately increased mortality 1. Substantial progress in diabetes monitoring and treatment has significantly increased the life expectancy of patients. As patients live longer, other comorbidities related to the diabetic condition have emerged, including a compromised skeletal health 2. Indeed, obese patients with T2DM experienced a 40 to 70% increased fracture risk despite a paradoxal normal to relatively high bone mineral density (BMD) compared to control subjects 3–6. These
Biomaterials are a key ingredient to the success of bone tissue engineering (TE), which focuses o... more 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.
Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foam... more Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foaming agent. Their porous structure was characterized through helium and mercury pyonometry, scanning electron microscopy (SEM) and X-ray microtomography observations coupled with image analysis. The pore size distributions obtained by these two latter techniques show that the pore structure is more homogeneous when the foaming process is
Aim X-ray microfocus computed tomography (µCT) is a very powerful technique for the characterisat... more Aim X-ray microfocus computed tomography (µCT) is a very powerful technique for the characterisation of the internal structure of materials in a quantitative and non-destructive way [1-5]. Many different µCT devices have been developed increasing the possibilities and applications for µCT-based analysis [6-11]. Recently, SkyScan NV [Kontich, Belgium] has developed an X-ray CT device to be installed in a scanning electron microscope (SEM), in the following referred to as the SEM-CT, which allows to investigate in the same device both the internal structure of materials in three dimensions down to the submicron level and the sample's surface topography [11]. The aim of this study is to investigate the capabilities and limitations of the SEM-CT system for materials research. Since the µCT-device is installed into a SEM, not only the target material of the SEM-CT device and the sample dimensions and morphology will influence the image quality, like in a normal µCT system, but also t...
Aims Main aim of this study was to determine the correlation between in-vitro cell behaviour and ... more Aims Main aim of this study was to determine the correlation between in-vitro cell behaviour and the strut surface roughness of Ti6Al4V scaffolds analysed based on micro-CT images. As the surface roughness determines the microscale morphology of the scaffold in quantitative way [1-4], appropriate surface topology analysis of the 3D porous structures is needed. Since commercially available profile measuring systems fail when determining the SSR of advanced porous structures, and because a high surface roughness of the struts compared to their dimensions causes difficulties for the quantitative determination of the surface morphology, a novel protocol for quantitative analysis of the surface morphology based on high resolution micro-CT images was used [4,5]. In-vitro biological experiment, with human periosteum derived cells (hPDCs) has been performed in order to analyse response of the osteogenic cells to different surface topologies of 3D scaffolds. Method Open porous bone scaffolds...
In order to understand and to simulate the functional behaviour of porous structures during loadi... more In order to understand and to simulate the functional behaviour of porous structures during loading, quantitative knowledge of the relationship between the morphology and the mechanical behaviour is necessary. Therefore, the porous structures need to be quantified morphologically. In this research, the quantification will be performed by using micro-CT. However, to date, this technique encounters some problems. Optimal acquisition parameters
To introduce a multimodular combination of techniques as a novel minimal invasive approach to inv... more To introduce a multimodular combination of techniques as a novel minimal invasive approach to investigate efficiently and accurately external cervical resorption (ECR). One case of a central incisor with extensive external cervical resorption was selected to demonstrate the potential of a comparative novel study methodology. ECR diagnosis was based on clinical inspection, digital radiography and cone-beam computed tomography (CBCT). After extraction the tooth was investigated using micro-focus computed tomography (micro-CT), nano-CT and hard tissue histology. These techniques were compared for their accuracy and applicability to highlight their advantages and disadvantages. Nano-CT was more effective than micro-CT and CBCT for detailed ex vivo exploration of ECR. The reparative tissue, pericanalar resorption resistant sheet (PRRS), pulp tissue reactions, resorption channels and their interconnection with the periodontal ligament space, were accurately visualised by detailed processi...
Om de relaties tussen de morfologie en de functionele eigenschappen van poreuze structuren te beg... more Om de relaties tussen de morfologie en de functionele eigenschappen van poreuze structuren te begrijpen en via eindige elementen te simuleren, om de uiteindelijke, bruikbare eigenschappen te relateren aan de productie en het bewerken van deze materialen, en om kennis te vergaren over de relatie tussen de morfologie en de mechanische eigenschappen enerzijds en het falingsgedrag anderzijds, zijn geschikte karakteriseringstechnieken nodig. X‑stralen microfocus computer tomografie (micro-CT) is een bruikbare oplossing, aangezien deze beeldvormingstechniek de mogelijkheid biedt om op een niet-destructieve manier een volledige 3D set van beelden te genereren die de interne architectuur visualiseren van de poreuze structuur op een microscopische schaal. Daarenboven laten de micro‑CT beelden een grondige beeldanalyse toe, wat resulteert in een uitgebreide, driedimensionale en kwantitatieve beschrijving van de morfologie van poreuze materialen; iets wat niet kan bereikt worden met andere kar...
We describe a non-destructive imaging method, named contrast-enhanced nanofocus X-ray computed to... more We describe a non-destructive imaging method, named contrast-enhanced nanofocus X-ray computed tomography (CE-nanoCT), that permits simultaneously imaging and quantifying in 3D the (sub)tissue architecture and (biochemical) composition of cartilage and bone in small animal models at a novel contrast and spatial resolution. To demonstrate the potential of this novel methodology, a newborn mouse was scanned using CE-nanoCT. This allowed simultaneously visualising the bone and cartilage structure much like the traditional alcian blue-alizarin red skeletal stain. Additionally, it enabled a 3D visualisation at such a high spatial image resolution that internal, micro-scale structures could be digitally dissected and evaluated for size, structure and composition. Ex vivo treatment with papain, that is known to specifically remove the non-calcified cartilage layer but keep the calcified cartilage intact, proved CE-nanoCT to be applicable to visualise the subdivisions within the hyaline car...
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