Endothelial cell cultures as a tool in biomaterial research

Progress in biocompatibility and tissue engineering would today be inconcei vable without the aid of in vitro techniques. Endothelial cell cultures rep resent a valuable tool not just in haemocompatibility testing, but also in the concept of designing hybrid organs. In the past endothelial cells (EC) have frequently been used in cytotoxicity testing of materials, especially polymers, used in blood-contacting implants, as well as for investigating s eeding technologies for vascular prostheses. At present the exponential dev elopment both in theory and practice of cell and molecular biology of the e ndothelium offers great promise in the biomaterial field. Up until now this EC research field has mostly been non-biomaterial orientated. Nevertheless , the relevance for biomaterial research is apparent. Four aspects will be concisely reviewed under the headings inflammation, with special reference to cell adhesion molecules (CAMs) and cytokines, angiogenesis, focusing on the healing response, signal transduction, presenting examples from cytokin e- and metal ion-induced up-regulation of genes coding for CAMs, and, final ly, endothelial functionality, with emphasis on the principal characteristi cs of the physiological endothelial phenotype. Finally, the application of these fields to three foci of biomaterial research will be discussed, empha sizing the role of EC culture techniques in controlling the host response t o biomaterials (microvascular EC), controlling EC functionality (promoting positive effects and down-regulating negative effects), and tissue engineer ing (integration of EC into hybrid organs/biosensors). The need for more co -culture and three-dimensional models will be stressed and data from the au thors' laboratory presented to illustrate these principles. (C) 1999 Kluwer Academic Publishers.