Carbon-nanotube reinforced vascular conduits

Cardiovascular diseases have remained one of the leading causes of death during the past decade, however fewer progress have been made in engineering small diameter vascular grafts. In this paper, vascular conduits were fabricated through an extrusion based bioprinting system. The generation of vascular conduits with natural polymer such as alginate needs to have improved mechanical properties in order to biomimic the natural blood vessel. Carbon nanotube (CNT) is one of the best candidates for this goal because it is known as the strongest material and possesses a simple structure. In this work, multi-wall carbon nanotubes (MWCNTs) were dispersed homogenously in alginate and printed using an extrusion-based system. The effects of using MWCNT as a reinforcement agent were investigated in mechanical, swelling and degradation tests. In vitro evaluation of printed conduits encapsulated in human umbilical vein smooth muscle cells (HUVSMCs) was performed to characterize the effects of CNT reinforcement on the biological performance of the conduits. Cell viability and tissue histology studies were conducted to explore effects of MWCNT on short term biocompatibility as well as long-term tissue formation.