New insights in osteocyte imaging by synchrotron radiation

Abstract

Bone health depends on the bone mineral density and mechanical strength, characterised quantitatively and inferred through qualitative parameters such as the trabecular and cortical micro-architecture, and other parameters describing the bone cells. Among these cells, the osteocyte has been recognised as the orchestrator of bone remodelling, playing a key role in directing osteoblastic and osteoclastic activities. Conventional optical and electron microscopies have greatly improved our understanding of the cell physiology mechanisms involved in different osteoarticular pathophysiological contexts, especially osteoporosis. More recently, imaging methods exploiting synchrotron radiation, such as X-ray tomography, ptychography, and deep ultraviolet and Fourier transform infrared spectroscopies, have revealed new biochemical, chemical and 3D morphological information about the osteocyte lacuna, the surrounding matrix and the lacuna–canalicular network at spatial length scales spanning microns to tens of nanometres. Here, we review recent results in osteocyte lacuna and lacuna–canalicular network characterisation by synchrotron radiation imaging in human and animal models, contributing to new insights in different physiologic and pathophysiological situations.

Lacunar-canalicular bone remodeling: Impacts on bone quality and tools for assessment

“…Tools that require synchrotron radiation, which delivers high-resolution imaging of bone structure and mineralization 27,61,76,92 but is limited to very few researchers, are reviewed briefly here and thoroughly elsewhere. [93][94][95][96]…”

“…The use of high-resolution microcomputed tomography (µCT) to monitor bone, including LCS network architecture, is the subject of several recent reviews [93][94][95] and is therefore discussed only briefly here. µCT allows for non-destructive three-dimensional analysis of internal bone tissue structure and mineralization.…”

Comparison of the 3D-Microstructure Between Alveolar and Iliac Bone for Enhanced Bioinspired Bone Graft Substitutes

“…Intercommunicating osteocytes residing in lacunae in close proximity to the IPS are considered regulators of bone homeostasis and mechanoreception (Bonewald, 2011;Hemmatian et al, 2017;Repp et al, 2017). The size and arrangement of osteocyte lacunae in osteons was measured in great detail in the femoral bone (Hannah et al, 2010;Carter et al, 2013;Dong et al, 2014;Portier et al, 2020). Data considering the osteocyte lacunae properties in different human bone entities suggest an interindividual, site-specific, and local regional heterogeneity in osteocyte lacunae properties (Klein-Nulend et al, 2013;Hesse et al, 2014a;Hesse et al, 2014b;Hesse et al, 2015;Bach-Gansmo et al, 2016;Hunter and Agnew, 2016;Portier et al, 2020).…”

“…The visualization, quantification, and consecutive understanding of the skeletal site-specific 3D microarchitecture may be fundamental for further understanding of the competence of bone transplants and optimizing future scaffold materials. 2D histomorphometric approaches to analyze bone microarchitecture have successfully been utilized, allowing resolutions in the nanometer range when using electron microscopy (Grüneboom et al, 2019;Portier et al, 2020). Synchrotron radiation micro-CT (SR µ-CT) provides an advanced method for non-destructive, high-resolution 3D imaging of bone microarchitecture (Peyrin et al, 2000;Hesse et al, 2014b;Grüneboom et al, 2019;Portier et al, 2020).…”

“…2D histomorphometric approaches to analyze bone microarchitecture have successfully been utilized, allowing resolutions in the nanometer range when using electron microscopy (Grüneboom et al, 2019;Portier et al, 2020). Synchrotron radiation micro-CT (SR µ-CT) provides an advanced method for non-destructive, high-resolution 3D imaging of bone microarchitecture (Peyrin et al, 2000;Hesse et al, 2014b;Grüneboom et al, 2019;Portier et al, 2020). SR µ-CT uses monochromatic or near-monochromatic beams to produce images with excellent brilliance, signal-to-noise ratio, spatial resolution, and contrast (Hesse et al, 2014b;Grüneboom et al, 2019;Portier et al, 2020).…”