Type of mechanical stimulation | Cell type | Transfection system | Change in transfection efficiency | Ref. |
---|---|---|---|---|
Uniaxial cyclic stretch (0-10%, 0.5 Hz, 60 min), equiaxial cyclic stretch (5%, 05. Hz, 15 min) and shear stress (0.5 3 degrees torsion, 0.5 Hz, 15 min) | Murine primary lung epithelial cells on silicone membranes | Cationic polymer TurboFect™ (ThermoFisher) or naked DNA added after loading | Independently on the type of stimulus, optimal loading regimens increased transfection efficiency, compared to less intense or more intense regimens (in terms of % time, loading time and frequency), for both polyplexes and naked DNA. Using TurboFect™, % transfection was ∼ 63% for mechanically loaded samples and ∼ 5%, for non-loaded control. | [217] |
Sine Wave Generator, 100 Hz, 10 V amplitude for 4 min | Myelogenous leukaemia cell line K562 in suspension | Naked siRNA added during loading | 10-time fold increase in transfection efficiency in mechanically loaded samples, compared to non-loaded control | [218] |
Uniaxial cyclic stretch, equiaxial cyclic stretch and shear stress bioreactors | Dendritic cells and mesenchymal stem cells on silicone membranes | TurboFectâ„¢ or Lipofectamineâ„¢ added after loading | Equiaxial cyclic stretch loading combined with Lipofectamineâ„¢ led to the highest transfection efficiency (60.21% for MSCs, and 65.06% for dendritic cells) | [219] |
Uniaxial stretching (10%, 0.5 Hz, 30 min) | HEK 293 on silicone membranes | Naked DNA added after loading | Uniaxial stretching allowed internalisation of naked DNA, resulting in transfection efficiency of 47%. No results shown for non-loaded controls | [220] |
Stretching or compression (compressing ratio 2%, 4%, 6% and stretching ratio 4%, 8%, 12%, 30, 60 and 100% duty cycle, 2, 10, 100, 1000 mHz, for 10 min) | A549 cells on silicone membranes | Lipofectamineâ„¢, added after mechanical loading | A 30% increase in transfection efficiency was observed for compressed samples (duty ratios 60% and 100%, loading frequency 2 mHz, compression ratio 4% and 6), compared to non-loaded control. A 40% decrease in transfection efficiency was observed in stretched samples, compared to non-loaded control. | [38] |
Ultrasound-induced mechanical stress (50 pulses of 250 μs in duration and 600 V in amplitude), combined with high electric field (electroporation) | In vivo rabbit retinas and in vitro chorioallantoic membrane | Naked DNA added during stimulation | 1000-fold increase in photons/s indicating a higher expression of the marker gene luciferase in samples subjected to ultrasound and electroporation treatments, compared to samples subjected to electroporation alone. | [221] |
Equibiaxial cyclic stretch (10% area stretch, 50% duty cycle, 0.5 Hz, time variable from 30 min to 24 h) | A549 on Pronectinsâ„¢-treated plates | Electroporation of naked DNA, performed before mechanical loading | Twenty-four hours of cyclic stretch induced a onefold to sixfold increase in transfection, compared to non-loaded control | [222] |
Equibiaxial stretch, either continuous or cyclic (10% area stretch, 10% duty cycle, 1 Hz, either 30 min or 24 h) | A549 on laminin-coated plates | Naked DNA, or lipoplexes composed of Lipofectin™ (Thermofisher) or electroporation. Transfection performed before and/or after loading | If performed before transfection, mechanical loading had no effect. If performed after transfection, cyclic—but not continuous—stretching significantly increased transfection efficiency for both Lipofectin™ and electroporation but had no effect on naked DNA delivery system. Specifically, 30 min of stretching was sufficient to achieve a 2-fold (for Lipofectin™) or even a 10-fold (for electroporation) increase in transgene expression. | [223] |