Table 1.
Summary table of the impacts on mammal cells of US at frequencies under 10 MHz. (↗: increase in, ↘: decrease in, N.A.: not available).
| Reference | Frequency (MHz) | Intensity or Pressure | Duty Cycle (%) |
Pulse Time (min) | Dose (J cm−2) |
Cells | Temperature Control | Biological Effects |
Hypothesis |
|---|---|---|---|---|---|---|---|---|---|
| [16] | 0.045, 1 | 10–400 mW cm−2 | 25 | 5 | 7.5–75 | Primary fibroblasts Primary osteoblasts Primary monocytes |
Rise ≤ 1.8 °C | ↗ proliferation ↗ collagen synthesis |
N.A. |
| [17] | 1 | 100–400 mW cm−2 | 10 | 1 | 0.6–2.4 | Human monocytes (U-937) T lymphoblasts (Molt-4) Lymphocytes (Jurkat) Leukemia cell line (HL 60) |
Rise ≤ 1 °C | ↗ DNA double strand breaks if I > 200 mW cm−2 | Free radicals formation, due to cavitation. |
| [18] | 1 | 300 mW cm−2 | 50 | 0.5–15 | 4.5–135 | Human adenocarcinoma epithelial cells (HeLa) | None | ↗ membrane permeabilization ↗ intracellular transport |
N.A. |
| [19] | 1.8 | 7 mW mL−1 | 65 | 0.33 | 91 J mL−1 | Human leukemia bone marrow cells (K562, KG1a) HL-60, human B cell precursor leukemia cells (Nalm-6) |
None | ↗ apoptosis Mild necrosis Virulent leukemic cells more sensitive |
Oxygen singlet formation, due to cavitation. |
| [20] | 1.48 | 0.045 MPa | 15–70 | 5–30 | N.A. | Rat pheochromocytoma adrenal medulla cells (PC-12) | None | ↗ proliferation | N.A. |
| [21] | 1 | 250 mW cm−2 | 20 | 30 | 90 | Mouse osteoblasts (MC3T3-E1) | Pre-heated water tank | ↗ proliferation ↗ migration |
N.A. |
| [22] | 1 | 1000–2000 mW cm−2 | 20 | 0.5 | 6–12 | Human aortic smooth muscle cells (HASM) | Rise ≤ 1 °C | Reversible fluidization for I = 1000 mW cm−2 Damages to the actin filaments for I = 2 W cm−2 |
Fluidization due to the compression wave causing a local cell deformation |
| [23] | 1 | 800–1000 mW cm−2 | 50 | 0.25 | 6–7.5 | Human oral squamous carcinoma cells (HSC-2) U-937 |
None | ↘ HSC-2 viability with microbubbles. No effect on U-937. No effect without microbubble. |
N.A. |
| [24] | 0.5, 1, 3.5, 5 | 1600–2000 mW cm−2 | 10–100 | 30 | 288–3600 | Endothelial cells | Measured temperature “excluded the possibility that thermal effects may cause changes in the cultured cells” | ↗ proliferation ↗ cytoskeleton disorganization ↗ tissue repair. |
direct mechanical action |
| [25] | 0.5, 1, 3, 5 | 250–1000 mW cm−2 | 20 | 5 | 15–60 | Mouse myoblasts (C2C12) | Room temperature (28 °C) water tank | ↗ proliferation ↗ differentiation |
Mechanical constraints |
| [26] | 0.8, 1.5 | 150, 250 kPa | 100 | 0.17–0.5 | N.A. | C2C12 | Rise ≤ 1 °C | Induce cytoskeleton fluidization ↗ cell mortality |
Cell deformation with acoustic pressure |
| [27] | 0.51, 0.994, 4.36 | N.A. | N.A. | N.A. | 3, 25, 50 | Human cardiac microvascular endothelial cells (hcMEC) Madin–Darby Canine Kidney cells (MDCK) Mouse neuroblastoma cells (Neuro2A) Human colon cancer cells (HT29) |
Perfused water tank at 37 °C | ↗ proliferation at low I Not anymore at high intensity |
N.A. |
| [28] | 0.51, 4.36 | N.A. | N.A. | N.A. | 3, 25 | Neural stem cells | Perfused water tank at 37 °C | ↗ proliferation no increase in neurogenesis or gliogenesis |
N.A. |
| [29] | 1 | 70–300 mW cm−2 | 100 | 30 | 126–540 | HeLa Human fetal lung fibroblasts (MCR-5) Human breast cancer cells (MCF-7) |
Rise ≤ 1 °C | ↗ mitotic abnormalities as a function of I disassembly of focal adhesions and microtubules. |
N.A. |