AbstractThe need for engineered devices to treat cardiovascular diseases is increasing due to an aging population and a changing lifestyle. Soft poly(n-butyl acrylate) (cPnBA) networks were recently described as polymer networks with adjustable mechanical properties and suggested as soft substrates for cells, which could potentially be used for cardiovascular implants. Vascular prostheses designed to be implanted in arteries should have an elasticity similar to blood vessels (elastic modulus at body temperature between 100 and 1200 kPa). Therefore, cPnBA networks with E-moduli of 250 kPa (cPnBA0250) and 1100 kPa (cPnBA1100) were developed. Recently, it was shown that both materials were non-cytotoxic for murin fibroblasts, human primary endothelial cells and human monocytes. However, before such newly developed polymers can be used in vivo, it has to be assured that the sterilized materials have a very low endotoxin load to avoid an unspecific activation of the immune system, which otherwise might cause local or systemic inflammatory responses and could lead to severe pathologies. In this study we investigated the immuno-compatibility of sterilized cPnBA0250 and cPnBA1100 with the help of an immuno-competent macrophage cell line as well as with whole human blood.