Nanostructure Promotes Growth of New Blood Vessels, Mimics Natural Protein
Tissue deprived of oxygen (ischemia) is a serious health condition that can lead to damaged heart tissue following a heart attack and, in the case of peripheral arterial disease in limbs, amputation, particularly in diabetic patients.
Northwestern University researchers have developed a novel nanostructure that promotes the growth of new blood vessels and shows promise as a therapy for conditions where increased blood flow is needed to supply oxygen to tissue.
“An important goal in regenerative medicine is the ability to grow blood vessels on demand,” said Samuel I. Stupp, Board of Trustees Professor of Chemistry, Materials Science and Engineering, and Medicine. “Enhancing blood flow at a given site is important where blood vessels are constricted or obstructed as well as in organ transplantation where blood is needed to feed the cells properly.”
Stupp led the study that will be published the week of Aug. 1 by the Proceedings of the National Academy of Sciences (PNAS).
Stupp and his team designed an artificial structure that, like the natural protein it mimics, can trigger a cascade of complex events that promote the growth of new blood vessels. The protein the nanostructure mimics is called vascular endothelial growth factor, or VEGF.
The nanostructure, however, exhibits important advantages over VEGF: it remains in the tissue where it is needed for a longer period of time; it is easily injected as a liquid to the tissue; and, relative to the protein, it is inexpensive to produce. (VEGF was tested in human clinical trials but without good results, possibly due to it remaining in the tissue for only a few hours.)
“One of the major challenges in the field of ischemic tissue repair is sustained delivery of therapeutic agents to target tissue,” said Douglas W. Losordo, M.D., a co-author of the paper and director of Northwestern’s Feinberg Cardiovascular Research Institute. “Native VEGF has a very short tissue half-life, limiting its potency and requiring repeat dosing. By virtue of its engineering, this nanomaterial mimics VEGF but is capable of much longer life in the tissue, greatly enhancing its potency.”