A 4D time-lapse morphometry method to quantify bone formation and resorption during distraction osteogenesis.

Distraction osteogenesis (DO) is widely utilized for treating limb length discrepancy, nonunion, bone deformities and defects. This study sought to develop a 4D time-lapse morphometry method to quantify bone formation and resorption in mouse femur during DO based on image registration of longitudinal in vivo micro-CT scans. Female C57BL/6 mice (n = 7) underwent osteotomy, followed by 5 days of latency, 10 days of distraction and 35 days of consolidation.

The accordion technique did not improve bone healing in a mouse model of distraction osteogenesis.

Distraction osteogenesis (DO) is a valuable surgical method for limb lengthening and bone defect correction, but its lengthy consolidation phase presents challenges. The accordion technique (AT), involving compression and distraction of bone segments, has shown potential for enhancing healing. This study aimed to investigate the effectiveness of the AT conducted at three different time points (distraction phase, early consolidation phase, or late consolidation phase) compared to conventional DO in a mouse osteotomy model.

Planar cell polarity zebrafish models of congenital scoliosis reveal underlying defects in notochord morphogenesis.

Congenital scoliosis (CS) is a type of vertebral malformation for which the etiology remains elusive. The notochord is pivotal for vertebrae development, but its role in CS is still understudied. Here, we generated a zebrafish knockout of ptk7a, a planar cell polarity (PCP) gene that is essential for convergence and extension (C&E) of the notochord, and detected congenital scoliosis-like vertebral malformations (CVMs).

The Lacunocanalicular Network is Denser in C57BL/6 Compared to BALB/c Mice.

The lacunocanalicular network (LCN) is an intricate arrangement of cavities (lacunae) and channels (canaliculi), which permeates the mineralized bone matrix. In its porosity, the LCN accommodates the cell network of osteocytes. These two nested networks are attributed a variety of essential functions including transport, signaling, and mechanosensitivity due to load-induced fluid flow through the LCN.

Bone mechanical properties were altered in a mouse model of multiple myeloma bone disease.

Multiple myeloma bone disease (MMBD) is characterized by the growth of malignant plasma cells in bone marrow, leading to an imbalance in bone (re)modeling favoring excessive resorption. Loss of bone mass and altered microstructure characterize MMBD in humans and preclinical animal models, although, no study to date has examined bone composition or material properties. We hypothesized that MMBD alters bone composition, mineral crystal properties and mechanical properties in the MOPC315.

Resonance Frequency Analysis Identifies Implant- and Host-Related Factors Associated With Bone-Anchored Hearing Implant Stability.

Hypothesis: Resonance frequency analysis (RFA) is a reliable, noninvasive method to assess the stability of bone-anchored hearing implants (BAHIs), although surgical-, implant-, and host-related factors can affect its outcome.

Background: BAHI plays an important role in restoring hearing function. However, implant- and host-related factors contribute to premature implant extrusion.

Swim training induces distinct osseous gene expression patterns in anosteocytic and osteocytic teleost fish.

The traditional understanding of bone mechanosensation implicates osteocytes, canaliculi, and the lacunocanalicular network in biomechanical adaptation. However, recent findings challenge this notion, as shown in advanced teleost fish where anosteocytic bone lacking osteocytes are nevertheless responsive to mechanical load. To investigate specific molecular mechanisms involved in bone mechanoadaptation in osteocytic and anosteocytic fish bone, we conducted a 5-min single swim-training experiment with zebrafish and ricefish, respectively.

Spatial variations in the osteocyte lacuno-canalicular network density and analysis of the connectomic parameters.

Osteocyte lacuno-canalicular network (LCN) is comprised of micrometre-sized pores and submicrometric wide channels in bone. Accumulating evidence suggests multiple functions of this network in material transportation, mechanobiological signalling, mineral homeostasis and bone remodelling. Combining rhodamine staining and confocal laser scanning microscopy, the longitudinal cross-sections of six mouse tibiae were imaged, and the connectome of the network was quantified with a focus on the spatial heterogeneities of network density, connectivity and length of canaliculi.

CHD7 regulates craniofacial cartilage development via controlling HTR2B expression.

Mutations in the Chromodomain helicase DNA-binding protein 7 - coding gene (CHD7) cause CHARGE syndrome (CS). Although craniofacial and skeletal abnormalities are major features of CS patients, the role of CHD7 in bone and cartilage development remain largely unexplored. Here, using a zebrafish (Danio rerio) CS model, we show that chd7-/- larvae display abnormal craniofacial cartilage development and spinal deformities.

From breast cancer cell homing to the onset of early bone metastasis: The role of bone (re)modeling in early lesion formation.

Breast cancer often metastasizes to bone, causing osteolytic lesions. Structural and biophysical changes are rarely studied yet are hypothesized to influence metastasis. We developed a mouse model of early bone metastasis and multimodal imaging to quantify cancer cell homing, bone (re)modeling, and onset of metastasis.

Tensile Mechanical Properties of Dry Cortical Bone Extracellular Matrix: A Comparison Among Two Osteogenesis Imperfecta and One Healthy Control Iliac Crest Biopsies.

Osteogenesis imperfecta (OI) is a genetic, collagen-related bone disease that increases the incidence of bone fractures. Still, the origin of this brittle mechanical behavior remains unclear. The extracellular matrix (ECM) of OI bone exhibits a higher degree of bone mineralization (DBM), whereas compressive mechanical properties at the ECM level do not appear to be inferior to healthy bone.

Does tissue fixation change the mechanical properties of dry ovine bone extracellular matrix?

Tissue fixation is a prevalent method for bone conservation. Bone biopsies are typically fixed in formalin, dehydrated in ethanol, and infiltrated with polymethyl methacrylate (PMMA) Since some experiments can only be performed on fixed bone samples, it is essential to understand how fixation affects the measured material properties. The aim of this study was to quantify the influence of tissue fixation on the mechanical properties of cortical ovine bone at the extracellular matrix (ECM) level with state-of-the-art micromechanical techniques.

Breed and loading history influence in vivo skeletal strain patterns in pre-pubertal female chickens.

The influence of loading history on in vivo strains within a given specie remains poorly understood, and although in vivo strains have been measured at the hindlimb bones of various species, strains engendered during modes of activity other than locomotion are lacking, particularly in non-human species. For commercial egg-laying chickens specifically, there is an interest in understanding their bones' mechanical behaviour, particularly during youth, to develop early interventions to prevent the high incidence of osteoporosis in this population. We measured in vivo mechanical strains at the tibiotarsus midshaft during steady activities (ground, uphill, downhill locomotion) and non-steady activities (perching, jumping, aerial transition landing) in 48 pre-pubescent female (egg-laying) chickens from two breeds that were reared in three different housing systems, allowing varying amounts and types of physical activity.

A 6-bromoindirubin-3'-oxime incorporated chitosan-based hydrogel scaffold for potential osteogenic differentiation: Investigation of material properties in vitro.

Effective treatments for critical size bone defects remain challenging. 6-Bromoindirubin-3'-Oxime (BIO), a glycogen synthase kinase 3β inhibitor, is a promising alternative for treatment of these defects since it aids in promoting osteogenic differentiation. In this study, BIO is incorporated into a new formulation of the guanosine diphosphate cross-linked chitosan scaffold to promote osteogenic differentiation.

Effect of the accordion technique on bone regeneration during distraction osteogenesis: A computational study.

Background And Objective: Distraction osteogenesis (DO), a bone lengthening technique, is widely employed to treat congenital and acquired limb length discrepancies and large segmental bone defects. However, a major issue of DO is the prolonged consolidation phase (10-36 months) during which patients must wear a cumbersome external fixator. Attempts have been made to accelerate the healing process of DO by an alternating distraction and compression mode (so-called "accordion" technique or AT).

In vivo microCT-based time-lapse morphometry reveals anatomical site-specific differences in bone (re)modeling serving as baseline parameters to detect early pathological events.

The bone structure is very dynamic and continuously adapts its geometry to external stimuli by modeling and remodeling the mineralized tissue. In vivo microCT-based time-lapse morphometry is a powerful tool to study the temporal and spatial dynamics of bone (re)modeling. Here an advancement in the methodology to detect and quantify site-specific differences in bone (re)modeling of 12-week-old BALB/c nude mice is presented.

Bone strength and composition in spacefaring rodents: systematic review and meta-analysis.

Studying the effects of space travel on bone of experimental animals provides unique advantages, including the ability to perform post-mortem analysis and mechanical testing. To synthesize the available data to assess how much and how consistently bone strength and composition parameters are affected by spaceflight, we systematically identified studies reporting bone health in spacefaring animals from Medline, Embase, Web of Science, BIOSIS, and NASA Technical reports. Previously, we reported the effect of spaceflight on bone architecture and turnover in rodents and primates.

3D Image Registration Marginally Improves the Precision of HR-pQCT Measurements Compared to Cross-Sectional-Area Registration in Adults With Osteogenesis Imperfecta.

Repositioning error in longitudinal high-resolution peripheral-quantitative computed tomography (HR-pQCT) imaging can lead to different bone volumes being assessed over time. To identify the same bone volumes at each time point, image registration is used. While cross-sectional area image registration corrects axial misalignment, 3D registration additionally corrects rotations.

In vivo and in silico monitoring bone regeneration during distraction osteogenesis of the mouse femur.

Background And Objective: Distraction osteogenesis (DO) is a mechanobiological process of producing new bone by gradual and controlled distraction of the surgically separated bone segments. Mice have been increasingly used to study the role of relevant biological factors in regulating bone regeneration during DO. However, there remains a lack of in silico DO models and related mechano-regulatory tissue differentiation algorithms for mouse bone.