Table 2.
Material Properties, Applied Mechanical Stimuli, and Resulting Findings From Selected Cell Mechanobiology Studies
| Authors | Application | Material Properties | Stimuli | Outcome |
|---|---|---|---|---|
| Mak et al.107 | Canalicular flow | Bone (extracellular matrix): E = 15,000, ν = 0.25, k = 0.13e−15 | 2000 με compression | Abrupt changes in drag forces as canaliculus approaches a microporosity (~8e8 Pa/m) |
| Anderson et al.108 | Lacunar–canalicular flow | Idealized geometry, μ = 0.000855 | P i = 300 Pa, P o = 150, 0 Pa | Cell body primarily exposed to hydrodynamic pressure (~150 Pa), cell processes primarily exposed to shear stress (1.8–7 Pa) |
| Anderson and Knothe Tate109 | Lacunar–canalicular flow | Gap size = 0.01–0.2 µm, μ = 0.001 | Max V i: 3.28e−5 m/s | Physiologically representative localized variations in canalicular geometry increase shear stress stimulation to osteocyte (0.58) |
| Rath Bonivtch et al.110 | Lacunar strain | Bone (extracellular matrix): E = 25,000, ν = 0.3; pericellular matrix: E = 15,000–35,000, ν = 0.3 | 2000 με compression | Strain amplification in the lacuna (2957 με), increasing with inclusion of canaliculi (6036 με) |
| Verbruggen et al.111 | Osteocyte strain | Realistic geometry (confocal microscopy): bone (extracellular matrix): E = 16,000, ν = 0.38; pericellular matrix: E = 0.04, ν = 0.4; osteocyte: E = 0.00447, ν = 0.3 | 3000 με compression | Strain amplification in osteocyte due to realistic geometry (24,333 με), and due to ECM projections (12,000 με) |
| Varga et al.112 | Osteocyte strain | Realistic geometry (synchrotron X‐ray nano‐tomography): bone (extracellular matrix): E = 16,000, ν = 0.38; pericellular matrix: E = 0.04, ν = 0.4; osteocyte: E = 0.00447, ν = 0.3 | 1000 με compression | No relationship between morphological parameters and localized strain. Amplification of strain in the lacuna (~10,000 με) and in the osteocyte (~70,000 με) |
| Verbruggen et al.113 | Multiphysics osteocyte stimuli | Realistic geometry (confocal microscopy): bone (extracellular matrix): E = 16,000, ν = 0.38; pericellular matrix: E = 0.04, ν = 0.4; osteocyte: E = 0.00447, ν = 0.3; μ = 0.000855 | 3000 με compression, P i = 300 Pa, P o = 0 Pa | Multiphysics predictions of interstitial fluid velocity (~60.5 µm/s) and maximum shear stress stimulation (~11 Pa), and osteocyte strain amplification (~10,000 με) |
| Barreto et al.114 | Strain stimulation of cytoskeleton | Cytoplasm: E = 0.00025, ν = 0.49; nucleus: E = 0.001, ν = 0.3; microtubules: E = 2000, ν = 0.3; actin cortex: E = 0.002, ν = 0.3; actin bundles: E = 0.341, ν = 0.3 | 0.25 µm compression | Cell stimulation is highly dependent on the thickness, Young's modulus, and rigidity of the actin cortex |
| Khayyeri et al.115 | Primary cilia stimulation | Cytoplasm: E = 0.00025, ν = 0.49; nucleus: E = 0.001, ν = 0.3; microtubules: E = 2000, ν = 0.3; actin cortex: E = 0.002, ν = 0.3; actin bundles: E = 0.341, ν = 0.3; primary cilia: E = 0.178, ν = 0.3; μ = 0.001 | V i = 1 mm/s, V o = 0 mm/s | Multiphysics model predicts length and stiffness of primary cilium are responsible for transmission of mechanical stimuli to cytoskeleton. Highest strains were found at the base of the primary cilium (~100,000 με) |
| Vaughan et al.116 | MSC strain stimulation in bone marrow | Adipocyte: E = 0.0009, ν = 0.4; MSC: E = 0.0025, ν = 0.4; plasma: E = 0.000001, ν = 0.49; trabecular bone: E = 10,000, ν = 0.3; trabecular bone marrow: E = 0.001, ν = 0.49 | 3000 με compression | Osteogenic strain stimulation occurs under normal conditions (~24,000 με), with reduced bone volume fraction leading to increased stimulation (~48,000 με). Increased adipocyte content during osteoporosis reduced MSC stimulation via a shielding effect (~41,000 με) |
| Vaughan et al.117 | Multiphysics models of in vitro and in vivo bone cell mechanosensors | Cytoplasm: E = 0.00447, ν = 0.4; nucleus: E = 0.01788, ν = 0.4; primary cilium: E = 0.178, ν = 0.4; trabecular bone: E = 10,000, ν = 0.3; trabecular bone marrow: E = 0.001, ν = 0.49, μ = 0.001, ρ = 997 | V i = 34.7 mm/s (in vitro), V i = 14.8 µm/s (in vivo) | Cells highly stimulated in vitro by both integrin attachments (>200,000 με) and primary cilium (~220,000 με). In vivo cells also highly stimulated by integrin attachments (~270,000 με), while primary cilium was only stimulatory when attached to lacunar bone (~110,000 vs 2000 με) |
E is Young's modulus (MPa), k is permeability (m4/N s), μ is fluid dynamic viscosity (N s/m2), ρ is fluid density (kg/m3), υ is Poisson's ratio, P i and P o denote pressure at inlet and outlet, and V i and V o denote velocity at inlet and outlet.