Simulation study on parameter dependence of dynamic osteocyte response under low-magnitude high-frequency vibration

Area of Science:

• Biomedical Engineering
• Mechanobiology
• Cellular Biomechanics

Background:

• Osteocytes, crucial mechanosensors in bone, respond dynamically to mechanical stimuli.
• Understanding osteocyte responses to whole-body vibration is vital for bone health interventions.
• Low-amplitude high-frequency vibration (LMHFV) is a potential therapeutic modality for bone disorders.

Purpose of the Study:

• To investigate the dynamic response mechanism of osteocytes to whole-body LMHFV using numerical simulation.
• To analyze the effects of vibration parameters (acceleration amplitude and frequency) on osteocyte mechanical responses.
• To determine optimal LMHFV parameters for enhancing the osteocyte mechanical microenvironment.

Main Methods:

• A finite element model of a single bone lacuna-osteocyte, including the cytoskeleton, was developed.
• Numerical simulations were performed to analyze dynamic responses under various LMHFV protocols.
• Key mechanical parameters such as fluid pressure and von Mises stress were evaluated.

Main Results:

• LMHFV induces alternating positive and negative liquid pressure and increases fluid shear stress on osteocytes, with effects dependent on acceleration amplitude.
• Optimal parameter ranges (e.g., 0.026 g-0.038 g, 30 Hz) yield higher liquid pressure magnitudes.
• Cytoskeletal stress, particularly on microtubules, varies non-linearly with vibration parameters, with specific ranges (0.02 g-0.03 g, 30-45 Hz) enhancing signal transmission.

Conclusions:

• LMHFV, when applied with appropriate parameters, can significantly improve the mechanical microenvironment of osteocytes.
• Optimized vibration protocols can enhance osteocyte bioactivity by modulating mechanical signals.
• This study provides insights into the mechanotransduction pathways in osteocytes under vibration, supporting potential therapeutic applications.