Ultrasound for microvascular tissue engineering

A critical obstacle currently facing the field of tissue engineering is the need for rapid and effective tissue vascularization strategies, both during construct development and upon implantation. To address this challenge, we have developed an ultrasound technology for microvascular tissue engineering. The technology utilizes radiation forces in an ultrasound standing wave field to rapidly and non-invasively spatially pattern cells in 3D within hydrogels. Ultrasound-induced patterning of endothelial cells accelerates the emergence of capillary-like sprouts stimulates cell-mediated collagen fibril alignment and results in the maturation of sprouts into lumen-containing microvessel networks throughout collagen hydrogels. Importantly, the morphology of resultant microvessel networks can be controlled by design of the acoustic field employed during fabrication. Specifically, the technology can produce microvascular networks having two distinct, physiologically relevant morphologies; one composed of a tortuous, capillary-like network, and one composed of hierarchical branching vessels (arteriole/venule-like). We have extended the versatility of the technology to lymph endothelial cells and have demonstrated the ability to engineer 3D lymphatic microvessel structures. Thus, this ultrasound technology holds promise as a new approach to induce microvascular network formation and direct vascular morphology in engineered tissues.