LIUS (Low Intensity UltraSound) has been used to enhance bone healing, repair of damaged muscle, and differentiation of mesenchymal stem cells into osteoblasts or chondrocytes. Ultrasound can improve cell viability, thanks to its ability to get molecules moving, and researchers have used it to increase blood flow to tissues in the process of healing and regenerating. In particular, low-intensity ultrasound (LIUS) has been used to help regenerate cartilage and bone, and in tissue engineering to stimulate cells.
Journal of Tissue Engineering – Indirect Low-Intensity Ultrasonic Stimulation for Tissue Engineering
Low-intensity ultrasound (LIUS) treatment has been shown to increase mass transport, which could benefit tissue grafts during the immediate postimplant period, when blood supply to the implanted tissue is suboptimal. In this in vitro study, we investigated effects of LIUS stimulation on dye diffusion, proliferation, metabolism, and tropomyosin expression of muscle cells (C2C12) and on tissue viability and gene expression of human adipose tissue organoids. We found that LIUS increased dye diffusion within adjacent tissue culture wells and caused anisotropic diffusion patterns. This effect was confirmed by a hydrophone measurement resulting in acoustic pressure 150–341 Pa in wells. Cellular studies showed that LIUS significantly increased proliferation, metabolic activity, and expression of tropomyosin. Adipose tissue treated with LIUS showed significantly increased metabolic activity and the cells had similar morphology to normal unilocular adipocytes. Gene analysis showed that tumor necrosis factor-alpha expression (a marker for tissue damage) was significantly lower for stimulated organoids than for control groups. Our data suggests that LIUS could be a useful modality for improving graft survival in vivo.