Physical energies to the rescue of damaged tissues

Table 1 Low-energy shock wave therapy studies

Low-energy shock wave therapy	Conditions	Biological effects	References number
In vivo studies	Wound-healing disturbances, tendinopathies, and non-healing bone fractures	Activation of angiogenic pathways with local release of trophic mediators	[72-77]
	Myocardial infarction in animal models	Improvement of vascularization at the infarction border zone; Mobilization of endogenous progenitor cells from bone marrow into the systemic circulation and to the damaged myocardium; Increase in VEGF gene and protein expression with endothelial cell proliferation	[82-88]
	Human severe coronary artery disease or severe angina	Improvement of myocardial ischemia and chest pain	[89-90]
	Human acute myocardial infarction	Suppression of left ventricular remodeling and enhancement of myocardial function	[91]
	Spinal cord injury in rats	Induction of endogenous neural stem cells and functional improvement	[96]
	Diabetic bladder dysfunction in rat model	Improvement of voiding function; Enhancement of innervation and vascularization	[97]
In vitro studies	Adipose- and bone marrow-derived mesenchymal stem cells	Induction of osteogenic differentiation	[92-94]
	Murine adipose derived stem cells	Stem cell proliferation and migration in an Erk1/2-dependent fashion	[81,95]

Table 2 Electromagnetic field studies

Electromagnetic fields	Conditions	Biological effects	References number
Extremely low-frequency pulsed magnetic fields	Adult ventricular cardiomyocytes	Induction of the expression of endorphin genes and peptides; Control of intracellular calcium and pH homeostasis; Regulation of myocardial growth; Orchestration of stem cell cardiogenesis	[101-109]
	Mouse embryonic stem (ES) cells	Induction of cardiogenesis, cardiac gene and protein expression, ensuing into a high-throughput of spontaneously beating cardiomyocytes	[110]
Radioelectric field of 2.4 GHz (REAC)	Mouse ES cells, hADSCs and human skin fibroblasts	Optimization in the expression of pluripotency/multipotency; Increase in commitment along myocardial, skeletal muscle, and neuronal fates, with a biphasic effect on the transcription of stemness genes	[111-117]
	hADSCs	Reduction of senescence-associated β-galactosidase expression; Overexpression of the TERT gene associated with an increase in telomerase activity; Overexpression of the BMI1 gene; REAC effects counteracted by chemical inhibition of type-2 hyaluronan synthase	[118-120]
	PC12 cells, a rat cell line of pheochromocytoma	Induction of the neurological and morphofunctional differentiation; Up-regulation of neurogenic genes; Decrease in PC12 cells	[132]

ES cells: Embryonic stem cells; hADSCs: Human adipose tissue-derived stem cells; REAC: Radio electric asymmetric conveyer.

Table 3 Photobiomodulation studies

Photobiomodulation	Conditions	Biological effects	References number
LLLT	Tumor transplantation in rats	Failure to affect the implanted tumor; Stimulation of hair regrowth and wound healing	[135-138]
Cell-generated electromagnetic (light) signals	Baby hamster kidney cells on thin glass film	Cell migration and orientation afforded by endogenous generation and processing of signals carried out by electromagnetic radiation (light)	[139]
Near-infrared light scattering	Cell culture	Near-infrared light scattering by cells mediates long-range attraction between them and aggregation within the culture system	[140]
PBM with blue (420 nm) or green (540 nm) light	hADSCs	Promotion of osteoblastic differentiation; Overexpression of a gene program of osteogenesis; Increase of intracellular calcium mediated by the activation of light-gated calcium ion channels	[141, 142]
PBM with red (660 nm) or near-infrared (810 nm) light	hADSCs	Induction of cell proliferation; Maintenance of low ROS level	[151]
PBM with blue (415 nm) or green (540 nm) light	hADSCs	Inhibition of cell proliferation; Increase of low ROS level; Lowering of mitochondrial membrane potential and intracellular pH	[151]
Various forms of PBM	Acute stroke in animal models	Improvement of the outcome of acute stroke	[152-157]
PBM with 810 nm laser light	Human moderate-to-severe stroke associated with neurological defects	Long-lasting neurological improvement	[158-160]
Near-infrared light scattering (665 nm and 810 nm)	Traumatic brain injury in animal models	Rescue of neurological performance and reduction of the size of brain lesions; Increase of neuroprogenitor cells in mouse dentate gyrus and subventricular zone; Increase of learning memory; Improvement of mitochondrial function	[161-168]
Near-infrared light scattering (665 nm and 810 nm)	Human traumatic brain injury	Improvement of both language and cognitive performance, as well as brain tissue recovery	[169-171]
PBM with near-infrared (810 nm) light	Alzheimer’s disease in animal models	Reduction of amyloid beta plaques; Decrease in the expression of pro-inflammatory cytokines; Increase in mitochondrial function, and ATP levels	[172]
PBM with near-infrared (810 nm) light	Human Alzheimer’s disease	Improvement in Alzheimer's Disease Assessment Scale - Cognitive assessment; Enhancement of cerebral microcirculation	[173-174]
PBM with near-infrared (810 nm) light	Parkinson’s disease in animal models	Increase in the number of dopaminergic neurons	[175-176]
PBM with near-infrared (810 nm) light	Human Parkinson’s disease	Improvement of the investigated indicators of balance, including gait, cognitive function, and speech	[177]
LLLT	Acute Myocardial infarction in the pig	Reduction of scarring; Improvement of heart function; Stem cell mobilization and recruitment to the ischemic heart	[178]

LLLT: Low level light therapy; hADSCs: Human adipose tissue-derived stem cells; PBM: Photobiomodulation.