Elastic large muscular vessel wall engineered with bone marrow-derived cells under pulsatile stimulation in a bioreactor

Bone marrow‑derived cells (BMCs) have demonstrated their ability to differentiate into multiple cell lineages and may be a promising cell source for vascular tissue engineering. Although much progress has been made in the engineering of small blood vessels (<6 mm in diameter) with biodegradable materials such as polyglycolic acid (PGA), it remains a challenge to engineer large vessels (>6 mm in diameter) due to unsatisfactory biomechanical properties. The present study was to engineered an elastic large vessel wall (6 mm in diameter) using a PGA unwoven fibre scaffold covered with BMCs from canine humeri. The cell‑PGA sheet was then loaded into a bioreactor designed for the present study, with dynamic pulsatile culture conditions to mimic the physiological vessel environment. After four weeks of the pulsatile stimuli culture, an elastic vessel wall was formed. Histological analyses demonstrated that layers of smooth muscle‑like cells and well‑oriented collagenous fibres were evenly oriented in the dynamic group. By contrast, disorganised cells and randomly collagenous fibres were apparent in the static group. Furthermore, the engineered vessel wall in the dynamic group exhibited significantly improved biomechanical properties compared with those in static culture group. The approach developed in the present study was demonstrated to have promising potential to be used for the engineering of large vessel as well as other smooth muscle cell‑containing tissues, including bladder, urethral and intestinal tissues.