The effect of polymer type and fiber orientation on the compliance properties of electrospun vascular grafts

Vascular diseases are a major source of fatalities globally. However, the lack of accessibility of autologous vessels and the poor efficacy of commercial small-diameter vascular grafts limit surgical alternatives. Researchers therefore aimed to develop vascular prostheses that meet all requirements. Apart from the benefits of tissue-engineered grafts, significant obstacles that still hinder successful grafting include compliance mismatch, dilatation, thrombus development, and the absence of elastin. Among these issues, compliance mismatch between native vessel and artificial vascular scaffold has been mentioned in the literature as a possible cause of intimal hyperplasia, suture site rupture and endothelial and platelet cell damage. As a result, the usage of suitable materials and optimized fabrication techniques are required to achieve better control over the characteristics and functionality of the grafts. In particular, in the case of electrospun vascular grafts, the compliance can be adjusted throughout a broad range of values by adjusting the electrospinning parameters such as material selection, fiber orientation, porosity, and wall thickness. In this study, the electrospun vascular grafts consisting of pure PCL, PLA, and their blends were produced by using two different rotation speeds to achieve the oriented and non-oriented scaffolds. The impact of polymer type and fiber orientation on the compliance properties was evaluated. The results revealed that both material selection and fiber alignment have a significant effect on the compliance levels. PCL100_R grafts had the highest compliance value whereas the PCLPLA50_O scaffold had the lowest.