The effect of pulsed therapeutic ultrasound on equine bone marrow-derived mesenchymal stem cells in vitro

To determine the effect of pulsed therapeutic ultrasound on in vitro equine bone marrow-derived mesenchymal stem cell (BM-MSC) proliferation, viability, and cytokine/growth factor production. Banked, cryopreserved BM-MSCs from six horses BM-MSCs from six horses were divided into control and treatment groups. Therapeutic ultrasound was applied using 20 % pulse rate, 10 min, 3.3 MHz, 1.5 Watts/cm 2 , based on pilot study data. Viability was assessed using AlamarBlue; cell proliferation was assessed by calculating the area fraction post treatment (time 0), 24, 48, 72 h. Cytokine (IL-17, IL-10, IL-6) and growth factor (VEGF-A, TGF- β1) analysis was performed at 24 h. No significant difference between treatment and control groups was found on viability (P = 0.087) or proliferation up to 72 h post-treatment (P > 0.072). No significant differences were present for IL-17 (P = 0.443), IL-10 (P = 0.746), IL-6 (P = 0.156), VEGF-A (P = 0.730) or TGF- β1 (P = 0.673). Results of this study suggest that pulsed therapeutic ultrasound does not negatively affect BM-MSC proliferation, viability, or cytokine/growth factor production. • Pulsed therapeutic ultrasound has no effects on equine BM-MSC proliferation in vitro. • Pulsed therapeutic ultrasound has no effects on equine BM-MSC viability in vitro. • Pulsed therapeutic ultrasound has no effect on equine BM-MSC cytokine or growth factor production in vitro.