Polyurethane/carbon nanotube (PU/Cnts) nanocomposites as vascular graft substitute: effect of cnts length

IntroductionCoronary vascular disease (CVD) is one of the major causes of mortality. A common method for combating CVD is coronary artery bypass grafting using autologous blood vessels. However, due to the availability of autologous vessels through prior removal, disease, or inadequate size mismatching, patients do not possess suitable replacement blood vessels. Hence, it is needed to use artificial bypass graft for occluded vessels treatment.ObjectivesConventional vascular grafts are often stiffer than the natural vessels and because of the mechanical properties mismatch in the attachment, they cause thrombosis and intimal hyperplasia. The focus of this study is investigating the role of carbon nanotubes length on mechanical properties of polyurethane/carbon nanotubes nanocomposite (PU/CNTsN).MethodsPU/CNTsN contained two types of CNTs in different lengths (1-2 μm and 5-10 μm) were fabricated by electrospinning and their mechanical properties were compared with conventional artificial grafts and natural blood vessels.ResultsMorphology studies showed bead-free and smooth structure for both nanocomposites with fiber diameters in the range of 500-600 nm. Considering mechanical properties of nanocomposites, samples contained CNTs with 5-10 μm in length, exhibit higher elastic modulus but both type of PU/CNTsNs showed less stiffness in compare to the conventional substitute.ConclusionElectrospun PU/CNTsNs with ECM like structure and less stiffness might be more appropriate for vascular graft substitute.

Keywords:

PU/CNTs nanocomposite , Synthetic vascular graft , Improvement of mechanical mismatch