Bioengineering functional human aortic vascular smooth‐muscle strips in vitro

The contraction and relaxation of VSM (vascular smooth muscle) are responsible for the maintenance of vascular tone, which is a major determinant of blood pressure. However, the molecular events leading to the contraction and relaxation of VSM are poorly understood. The development of three-dimensional bioengineered tissues provides an opportunity to investigate the molecular events controlling vascular tone in vitro. In the present study we used fibrin-gel casting to bio-engineer functional VSM strips from primary human aortic VSM cells. Our bioengineered VSM strips are functionally similar to VSM in vivo and remained viable in culture for up to 5 weeks. VSM strips demonstrate spontaneous basal tone and can generate an active force (contraction) of up to 85.2 μN on stimulation with phenylephrine. Bioengineered VSM strips exhibited Ca 2+ -dependent contraction and calcium-independent relaxation. The development of functional bioengineered VSM tissue provides a new in vitro model system that can be used to investigate the molecular events controlling vascular tone.