Scientists at Rice University and Baylor College of Medicine have developed a way to grow new blood vessels for use with lab-grown tissue. They started with polyethylene glycol (PEG), a nontoxic plastic in wide use in medical devices, and modified to mimic the body's normal extracellular matrix, the framework of proteins and sugars between cells that provides instructions and supports structure in tissues.

Reporting in the journal Acta Biomaterialia, they showed that by creating a gel-like structure that contained blood vessel-forming cells and growth signals, they could stimulate the cells to form blood capillaries. They also implanted the gels into the corneas of mice, where no natural blood vessels exist, and found that capillaries with normal blood flow were formed. This new technique could provide blood vessels in tissue grown in the lab, and potentially could be used to re-vascularize damaged tissues and restore blood supply, such as after heart attack or stroke.