Current in vitro and animal models for novel drug discovery and testing often do not accurately predict the efficacy or side effects experienced inhuman trials. Consequently, billions of dollars are spent establishing clinical trials that are doomed to fail. Inexpensive, three-dimensional (3D),vascularized human tissue models have the potential to accurately predict cytotoxicity and pharmacokinetics of new drugs. Additionally, vascularized tissue implants could be used to treat ischemic diseases such as ischemic heart disease and peripheral artery disease where blood flow has been lost.
Researchers at the University of Rochester sought to develop a technology to rapidly generate vascularized, 3D tissues using human cells. The researchers used non-invasive mechanical forces generated by ultrasound standing wave fields (USWFs) to spatially organize human endothelial cells within collagen hydrogels. In response to USWF-induced patterning, endothelial cells underwent vascular sprouting within 24 hours and extensive 3D network formation within four days after initial patterning. Morphological characteristics of the networks, such as vessel diameter, network density, and vessel orientation, were influenced by the acoustic parameters of the USWF such that many vascular architectures were engineered. Safe, inexpensive, USWF-based technologies could be implemented to quickly fabricate vascularized tissues en masse for testing of new drugs. Additionally, vascularized tissues could be engineered to mimic tissue-specific vascular morphologies, and be implanted to re-establish blood flow to ischemic areas in vivo.