Table 2.
Summary of bioreactor systems with corresponding mechanical stimulation protocols.
| Cells | Biomaterial | Set-up | 2D/3D culture | Stress regime, frequency [Hz] | Strain [%] | Time span of stimulation | Outcome | Authors |
|---|---|---|---|---|---|---|---|---|
| MECHANICAL STIMULATION | ||||||||
| Embryonic avian pectoralis muscle cells | Collagen constructs | Mechanical cell stimulator device (computerized) | 3D | Cyclic ramp stretch at a rate of 0.35 mm/h | Up to 300% | 3 days | Increase of proliferation, fusion and myotube length | Vandenburgh and Karlisch, 1989 |
| C2C12 myoblasts | Collagen hydrogel | Stimulation of rod-shaped tissue via custom-designed stress chamber | 3D | Cyclic, 60 Hz | 5% | 7 days | Dense, oriented myotubes | Okano and Matsuda, 1998b |
| Myoblasts | Porous collagen scaffold | Stimulation via bio-Stretch system | 3D | Continuous or cyclic uniaxial rapid ramp stretch (RRS) or cyclical ramp strain (CRS) | 7.5 and 15% | 6 h | MMP-2 expression, and hence extracellular matrix remodeling, is up-regulated in response to strain | Auluck et al., 2005 |
| Human skeletal muscle cells | Collagen/Matrigel® Mix | Stimulation of hBAMs by custom-made mechanical cell stimulator | 3D | 5-pulse at 5 Hz bursts for 2 min afterwards 28 min resting phase | 5% on day 8–10, 10% on day 10–12, 15% on day 12–16 | 8 days | Enhance myofiber diameter and area diminished tissue stiffness | Powell et al., 2002 |
| Myoblasts | Fibrin | Use of custom-made device | 3D | Tensile strain | 25 or 50% | 7 days | Fiber alignment along direction of strain | Matsumoto et al., 2007 |
| Primary muscle precursor cells | Collagen based acellular ECM scaffolds | Computerized bioreactor system | 3D | Cyclic stretch | 10% | 5–21 days | Generation of fast twitch and tetanic force after implantation | Moon et al., 2008 |
| Adult rat Muscle progenitor cells (MPCs) | BAM scaffolds from acellular bladder ECM | Stimulation via computer-controlled bioreactor system | 3D | Cyclic stretch 3x per min, for the first 5 mins every hour | 10% | 7 days | After implanting improved host recovery | Machingal et al., 2011; Corona et al., 2012 |
| Rat primary cells | Collagen | Sliding chamber model | 2D | Isometric tension | n/a | 21 days | 3D constructs made of aligned myotubes | Smith et al., 2012 |
| C2C12 myoblasts | Collagen constructs | Mechanical loads applied by tensioning culture force monitor bioreactor | 3D | Repetitive cyclic stretch Ramp stretch | 1% 10% | up to 12 h | IGF-IEa > upregulated by single ramp stretch, reduced by repetitive cyclic stretch MGF > upregulated by single ramp stretch and cyclic stimulation | Cheema et al., 2005 |
| C2C12 myoblasts | Aligned electrospun polyurethane (PU) fibers | Tubular custom-made setup, computer program controlled | 2D/3D | Repetitive cyclic stretch, 1 Hz for 1 h every 6 h | 5 or 10% with or without pre-strain of 5% static | 2–14 days | Alignment, contractile proteins | Liao et al., 2008 |
| C2C12 myoblasts | Biodegradable microfibrous scaffold [DegraPol(R)] | Stimulation of constructs via custom made bioreactor | 3D | 2 days ramp stretch (3.3%), afterwards cyclic stretch (5 pulse, 0.5 Hz, 3.4% burst stretches | 6.7% | 7–10 days | Enhanced MHC expression | Candiani et al., 2010 |
| C2C12 myoblasts | Fibrin hydrogels | Stimulation of constructs via MagneTissue bioreactor | 3D | Static strain | 10% | 9 days | Increased gene expression, myotube diameter and length | Heher et al., 2015 |