Related Experiment Video
Updated: May 11, 2026
09:19
Atomic Force Microscopy Measurements of Cartilage in Intact and Regenerating Axolotl Limbs
Published on: October 11, 2024
Apparent elastic modulus of ex vivo trabecular bovine bone increases with dynamic loading
Juan Vivanco1, Sylvana Garcia, Heidi L Ploeg
1Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, USA.
Summary
This study validated an ex vivo bone model to investigate mechanical stimuli on bone tissue. The model successfully mimicked in vivo cellular function, showing increased bone stiffness with minimal cell death.
Area of Science:
- Biomaterials Science
- Orthopedics
- Mechanobiology
Background:
- Bone tissue remodeling is influenced by mechanical stimuli, but the precise biological control mechanisms remain unclear.
- Understanding these mechanisms is crucial for developing effective treatments for bone diseases and injuries.
Purpose of the Study:
- To validate an ex vivo three-dimensional (3D) bone model for studying cellular responses to mechanical loading.
- To maintain active osteocytes and minimize bone tissue injury within this model.
Main Methods:
- Bovine trabecular bone cores were subjected to uniaxial compressive load using a ZETOS system for 21 days.
- A 'treatment' group received physiological strain (4000 µε), while a 'control' group had minimal loading for measurements.
- Histological analysis quantified apoptosis and active osteocytes; calcein staining identified bone formation.
Main Results:
- The treatment group showed a significant increase in elastic modulus (61%) compared to the control group (28%).
- Apoptosis rates in the loaded group (1.7%) were lower than in the control group (2.7%), with central apoptosis levels similar to in vivo observations.
- The 3D model effectively supported physiological responses to mechanical loads.
Conclusions:
- The validated ex vivo 3D model accurately mimics in vivo cellular responses to mechanical stimuli in bone tissue.
- This model provides a controlled environment for investigating bone adaptation and developing new therapeutic strategies.
Related Concept Videos
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
01:16Dynamic Modulus of Elasticity of Concrete
The dynamic modulus of elasticity assesses how a concrete structure deforms under impact or dynamic loads. It is typically higher than the static modulus of elasticity, measured under slow, steady loading conditions.
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by a...
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by a...
01:15Strain and Elastic Modulus
The quantity that describes the deformation of a body under stress is known as strain. Strain is given as a fractional change in either length, volume, or geometry under tensile, volume (also known as bulk), or shear stress, respectively, and is a dimensionless quantity. The strain experienced by a body under tensile or compressive stress is called tensile or compressive strain, respectively. In contrast, the strain experienced under bulk stress and shear stress is known as volume and shear...
01:20Normal Strain under Axial Loading
Normal strain under axial loading is an important concept in the field of mechanics of materials. Axial loading implies the application of a force along the axis of a material, like a column or bar. This force can either compress or stretch the material. In the context of axial loading, normal strain is the deformation experienced by the material in the direction of the loading force. It's calculated as the change in length divided by the original length of the material. This unitless ratio...
01:21Plastic Behavior
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and reloaded.
01:09Spongy Bone
All bones comprise an outer layer of compact bone, and an interior made up of spongy bone tissue, also called cancellous or trabecular bone. In long bones, spongy bone tissue is mainly found in the interior of the epiphyses (broad ends of the bone).
Spongy bone is more porous, and less dense compared to compact bone. It is composed of concentric lamellae that are arranged irregularly to form the trabecular network. In some bones, the spaces between trabeculae contain red marrow, where...
Spongy bone is more porous, and less dense compared to compact bone. It is composed of concentric lamellae that are arranged irregularly to form the trabecular network. In some bones, the spaces between trabeculae contain red marrow, where...