BME Seminar Series: Kelley Garvin

Ultrasound Standing Wave Fields Control the Spatial Distribution

Abstract

Controlling the spatial organization of cells and proteins within 3D engineered tissue represents a promising strategy to regulate cell behaviors that are essential for generating replacement tissues. We have been working to develop ultrasound standing wave fields (USWF) as a technology that can align cells and proteins into planar bands within three-dimensional collagen-based engineered tissue. We present data indicating that this change in spatial distribution affects cell behaviors important for the field of tissue engineering. The application of USWF to cell suspensions can result in radiation force-mediated movement of cells to areas of the field separated by half-wavelength intervals. USWF-induced cell distribution was maintained after removal of the sound field by polymerization of a type-I collagen gel around the organized cell “bands”. When fibronectin-null myofibroblasts are organized within a collagen gel in such a manner, cell-mediated collagen gel contraction is significantly enhanced over sham controls that did not receive USWF treatment. Arranging human umbilical vein endothelial cells into a banded pattern within collagen gels led to the formation of endothelial cell sprouts emerging from the cell bands. Together, these studies suggest that our USWF technology can potentially address at least two of the current challenges faced in the field of tissue engineering–improving the mechanical strength of tissue constructs and the vascularization of engineered tissue.