Biodegradable synthetic matrices that resemble the size scale, architecture and mechanical properties of the native extracellular matrix (ECM) can be fabricated through electrospinning. Tubular conduits may also be fabricated with properties appropriate for vascular tissue engineering. Achieving substantial cellular infiltration within the electrospun matrix in vitro remains time consuming and challenging. This difficulty was overcome by electrospraying smooth muscle cells (SMCs) concurrently with electrospinning of a biodegradable, elastomeric poly(ester urethane) urea (PEUU) small-diameter conduit. Constructs were cultured statically or in spinner flasks. Hematoxylin and eosin (H&E) staining demonstrated qualitatively uniform SMCs integration radially and circumferentially within the conduit after initial static culture. In comparison with static culture, samples cultured in spinner flasks indicated 2.4 times more viable cells present from MTT and significantly larger numbers of SMCs spread within the electrospun fiber networks by H&E image analysis. Conduits were strong and flexible with mechanical behaviors that mimicked those of native arteries, including static compliance of 1.6+/-0.5 x 10(-3)mmHg(-1), dynamic compliance of 8.7+/-1.8 x 10(-4)mmHg(-1), burst strengths of 1750+/-220 mmHg, and suture retention. This method to rapidly and efficiently integrate cells into a strong, compliant biodegradable tubular matrix represents a significant achievement as a tissue engineering approach for blood vessel replacement.