SUNDAY, June 8 (HealthDay News) -- Adding a little shear stress
along a vascular bypass graft during the procedure may help hold it
together better in the long run, according to a new study.
Researchers report that gradually adding parallel pressure -- as
opposed to normal perpendicular pressure -- to adult stem cells
used in a graft helps then bind to the surfaces of the vessel.
The finding, expected to be presented during the annual meeting
of the Society for Vascular Surgery being held in San Diego, could
help development of a new tissue-engineered stem cell vascular
bypass graft.
Integrins, molecules important for cell attachment on the
surface of the stem cells, appear to be stimulated by shear force,
according to the study. This helps these cells to remain attached
to the inside of blood vessels.
"Firm attachment of the stem cells to the vascular graft would
allow for the formation of a confluent monolayer of cells in the
hopes of improving graft function," lead researcher Dr. Paul J.
Dimuzio, a vascular surgeon at Thomas Jefferson University in
Philadelphia, said in a prepared statement.
During the study, the researchers exposed human adipose-derived
stem cells (ASC) differentiated toward endothelial-like cells to
physiological levels of shear stress. Measurements of integrin
activity and cell attachment were taken on sample culture plates
precoated with collagen I, fibronectin or gelatin -- all vascular
basement membrane components.
Future experiments will evaluate how well the stem cell grafts
function as a bypass for occluded arteries, according to one
researcher.
More information
The U.S. National Heart, Lung, and Blood Institute has more
about
coronary artery bypass grafting.
