A New Hope for Cardiovascular Patients
University of Wisconsin–Madison NPRC scientists have made a significant leap in heart surgery innovation: they’ve developed bioengineered arteries using stem cells that could one day transform how doctors perform vascular bypass procedures.
Why New Arteries Are Needed
Currently, when patients need small-diameter blood vessels for procedures like coronary bypass surgery, surgeons must use vessels from another part of the patient’s body. This approach is invasive, can be limited by the patient’s health, and is not always possible. Donor vessels are another option, but they often face immune rejection.
The Science Behind Bioengineered Grafts
The research team created a new kind of “off-the-shelf” artery by:
- Using pluripotent stem cells to generate arterial endothelial cells (AECs), the cells that line blood vessels.
- Attaching these cells to a small synthetic graft made of ePTFE (the same material as Teflon), which is specially coated with proteins inspired by mussels to help the cells stick.
- Testing the grafts in Rhesus macaques, a primate model similar to humans.
What Did They Find?
The scientists compared different types of grafts:
- Uncoated synthetic grafts
- Grafts lined with normal (wildtype) AECs
- Grafts lined with AECs modified to avoid immune detection (major histocompatibility complex (MHC) double knockout)
Surprisingly, the (MHC) double knockout grafts failed half the time, possibly due to innate immune cells (natural killer cells) attacking them. The wildtype grafts, however, worked well for six months, and the host’s own cells repopulated the graft, supporting long-term success.
What’s Next?
This study is a promising step toward creating ready-to-use, stem cell-based vascular grafts for heart and vascular surgeries. If successful in future human trials, these grafts could:
- Reduce the need for invasive vessel harvesting
- Expand surgical options for patients with limited vessel availability
- Lower the risk of immune rejection
The Big Picture
As Dr. Samuel Poore, a co-author, explains: “This is an exciting, collaborative project with the potential to be a true bench to bedside advancement.”
