Biology subjects

van Rietbergen, B.

Publications and source records attributed to van Rietbergen, B..

3 recordsLinked to original sources

bioRxiv2023

Incorporating strontium enriched amorphous calcium phosphate granules in collagen/collagen-magnesium-hydroxyapatite osteochondral scaffold improves subchondral bone repair

To date, osteochondral defect repair with a collagen/collagen-magnesium-hydroxyapatite (Col/Col-Mg-HAp) scaffold has demonstrated good clinical results. However, subchondral bone repair has been suboptimal, potentially leading to damage to the regenerated overlying neocartilage. This study aimed at improving the bone repair potential of this scaffold by incorporating strontium (Sr) ion enriched amorphous calcium phosphate (Sr-ACP) granules (100-150 {micro}m). Sr concentration of Sr-ACP was determined with ICP-MS at 2.49 {+/-} 0.04 wt.%. Then 30 wt.% ACP or Sr-ACP granules were integrated into the scaffold prototypes. The ACP or Sr-ACP granules were well distributed and embedded in the collagenic matrix demonstrated by micro-CT and scanning electron microscopy/energy dispersive x-ray spectrometry. Good cytocompatibility of ACP/Sr-ACP granules and ACP/Sr-ACP enriched scaffolds was confirmed in in vitro cytotoxicity assays. An overall promising early tissue response and good biocompatibility of both ACP and Sr-ACP enriched scaffolds were demonstrated in a subcutaneous mouse model. In a goat osteochondral defect model, significantly more bone observed at 6 months with the treatment of Sr-ACP enriched scaffolds compared to scaffold only in particular in the weight-bearing femoral condyle subchondral bone defect. Overall, the incorporation of osteogenic Sr-ACP granules in Col/Col-Mg-HAp scaffolds showed to be a feasible and promising strategy to improve subchondral bone repair.

bioengineering↗

bioRxiv2022

Characterization of three-dimensional bone-like tissue growth and organization under influence of curvature and directional fluid flow

The transition in the field of bone tissue engineering from bone regeneration to three-dimensional in vitro models has come with the challenge of recreating a dense and anisotropic bone-like extracellular matrix with cell culture. The creation of such an organized bone-like extracellular matrix has received little attention thus far. Although the mechanism by which bone extracellular matrix gains its structure is not fully understood, curvature (especially concavities), mechanical loading due to deformations or directional fluid flow, and osteocyte signaling have been identified as potential contributors. Here, guided by computational simulations, we evaluated three-dimensional cell and bone-like tissue growth and organization in a concave channel with and without directional fluid flow stimulation. Human bone-marrow derived mesenchymal stromal cells were seeded on donut-shaped silk fibroin scaffolds and stimulated to undergo osteogenic differentiation for 42 days statically or in a flow perfusion bioreactor. Constructs were investigated for cell distribution, and tissue growth and organization on day 14, 28, and 42. As a result, directional fluid flow was able to improve bone-like tissue growth but not organization. After 28 days of culture, when osteogenic differentiation was likely accomplished, cells tended to have a small preference for orientation in the tangential (i.e., circumferential) direction of the channel. Based on our results, we suggest that three-dimensional bone-like tissue anisotropy might be guided by curvature, while extracellular matrix production can be increased through the application of fluid shear stress. With this study, an initial attempt in three-dimensions was made to improve the resemblance of in vitro produced bone-like extracellular matrix to the physiological bone extracellular matrix.

bioengineering↗

bioRxiv2020

Supersampling Enables Accurate Microstructural Bone Adaptation Simulations in Human in vivo HR-pQCT Images

In silico trials of treatments in a virtual physiological human (VPH) would revolutionize research in the biomedical field. Hallmarks of bone disease and treatments can already be simulated in pre-clinical models and in ex vivo data of humans using microstructural bone adaptation simulations. The increasing availability of in vivo high resolution peripheral quantitative computed tomography (HR-pQCT) images provides novel opportunities to validate and ultimately utilize microstructural bone adaptation simulations to improve our understanding of bone diseases and move towards in silico VPH decision support systems for clinicians. In the present study, we investigated if microstructural bone adaptation simulations of in vivo human HR-pQCT images yielded accurate results. Since high-resolution ground truth images cannot be obtained in vivo, we applied an ex vivo approach to study resolution dependence and the effect of upscaling on morphometric accuracy. To address simulation initialisation issues, we developed an input regularisation approach to reduce initialisation shocks observed in microstructural bone adaptation simulations and evaluated upscaling as a way to improve the accuracy of model inputs. Finally, we compared our ex vivo results to simulations run on in vivo images to investigate whether in vivo image artefacts further affect simulation outcomes.

bioinformatics↗