Medium with blood-analog mechanical properties for cardiovascular tissue culturing

Physiological wall shear rates and stresses in vessel culture or tissue engineering are relevant for maintaining endothelial cell (EC) integrity. To this end, the culture medium should have an appropriate viscosity. The viscosity of a standard culture medium was increased using xanthan gum (XG) and compared with literature data on whole blood, resulting in a medium with blood-analog shear-thinning behavior (XG-medium). The measured osmolality of the XG-medium was 285+/-2 mOsm kg(-1), which is within a physiologically acceptable range. The XG-medium was compared to standard medium to verify whether XG alters vascular cell function. First, the effect of XG on the growth of human EC monolayers was determined. In addition, to study whether XG changes drug-induced vasoconstriction or endothelium-dependent vasodilation, different drugs were administered to porcine coronary artery rings in a solution with or without XG, measuring the isometric force developed. XG did not influence EC growth, nor did it change drug-induced vascular tone. Moreover, the ECs aligned in the direction of flow after 24 h of physiological shearing with XG-medium. We conclude that, unlike standard culture media, XG-medium as a blood-analog culture medium has rheological properties suitable for use in vessel culture and tissue engineering to induce physiological wall shear stresses at physiological flow rates.