A theoretical model for the prediction of the porosity of warp knitted scaffolds for vascular applications

Porosity is one of the important structural parameters for vascular scaffolds. The ideal porosity should permit free transport of nutrients and wasted products across the scaffold. Many methods, such as gravimetric method, mercury intrusion method and SEM method have widely been used to predict the porosity. However, theoretical models used for predicting the porosity of a scaffold produced from textile structure are still lacked. Warp knitted structure is a promising structure for the fabrication of scaffolds. The aim of this work is to establish a novel theoretical model which can predict the porosity of such scaffold. The results calculated from the model for the scaffolds knitted on a small circular warp knitting machine with the biodegradable material PGLA were compared with these calculated from the gravity model results and the experimental results of the modified method of weight. The results have shown that the present model can effectively predict the porosity of a warp knitted scaffold.