Tiny blood vessels grow better in the laboratory if the tissue surrounding them is less dense, University of Utah bioengineers have demonstrated.
Then the researchers created a computer simulation to predict such growth accurately - an early step toward treatments to provide blood supply to tissues damaged by diabetes and heart attacks and to skin grafts and implanted ligaments and tendons.
"Better understanding of the processes that regulate the growth of blood vessels puts us in a position ultimately to develop new treatments for diseases related to blood vessel growth," and to better understand cancer metastasis, says bioengineering professor Jeff Weiss of the university's Scientific Computing and Imaging Institute.
Weiss and Lowell Edgar, a postdoctoral fellow in bioengineering, published their study Wednesday, Jan. 22, in the Public Library of Science's online journal PLOS ONE
Like some previous studies, they showed that tiny blood vessels called capillaries grow, branch and interconnect best when the density of the surrounding tissue - called the "extracellular matrix" - is lower rather than higher. But unlike earlier research, they used pieces of real blood vessels from rats rather than single cells, and went on to develop an accurate if simplified computer simulation of the process.
Earlier work also focused on how the extracellular matrix, made mostly of collagen, sends chemical signals to promote capillary growth. The Utah study focused more on how the collagen's mechanical or physical properties - specifically, the density or "stiffness" of the matrix - affect blood vessel growth. Both their lab experiments and computer simulations showed that the denser or stiffer this collagen matrix, the more difficult it is for blood vessels to form a network necessary to supply blood to living tissue. This directly impacts healing or accepting new tissue implanted into the body.
Upon injury or receiving a skin graft, the body triggers "angiogenesis" - the body's process of creating new blood vessels from existing ones.