In vitro permeability, porosity and cell growth study in electrospin membranes for vascular grafts

Introduction and motivation Nowadays, the possibility of engineering vascular grafts by means of electrospinning has attracted interest for small-diameter blood vessels. Potential vascular application lies in their ability to generate microporous structures with a big surface area. However, little is know about the effect of such microstructure and its thickness, both regarding mass transportation as well as cell proliferation. The motivation of this work is to analyse the permeability, porosity and cell growth in electrospun membranes for vascular grafts. Methods by electrospinning membranes for grafts made of memory polyurethane foam were fabricated in two thicknesses, sample 0 between 0.2 and 0.9 mm and sample +1 between 0.9 and 1.0 mm, amongst which human cardiac fibroblasts were grown during an incubation period of up to 10 days. Porosity and permeability were assessed according to ISO 7198 and cell proliferation was analysed with scanning optical and electronic microscopy (SEM). Total sample number was 12 for each baseline thickness. Data analysis was conducted by ANOVA test. Results +1 samples presented an average permeability that was 55.5% lower than the 0 samples, 10.24% decrease in porosity associated to bigger cell growth, evidenced by syncytial cells. Conclusion The variation of microporous structures of great surface area in order to obtain grafts by means of electrospinning technique affects cell growth and subsequently their permeability and porosity, thus offering an opportunity for its potential use in small-diameter vascular applications.