The importance of angiogenesis in the interaction between polymeric biomaterials and surrounding tissue

The uncomplicated outcome of surgical interventions after biomedical application of biomaterials depends on successful wound healing. Wound healing is a highly complex process compossed of a number of overlapping phases, including inflammation, epithelialization, angiogenesis and matrix deposition. Inadequate angiogenesis limits the transport between the microvasculature and implanted biomaterials. The regulation of angiogenesis is based on numerous growth factors, proteolytic enzymes, extracellular matrix components, cell adhesion molecules, and vasoactive factors. Capillary endothelial cells were grown for different time periods (day 1, 3, 6, 9 and 12) on the surface of a recently developed biodegradable polymeric biomaterial. As control the cells were seeded on the gelatine coated polystyrene surface of commercially available cell cultures dishes. Endothelial cells became adherent and showed confluent cells layers during increasing time period on both surfaces. The total cell number of cells grown on the gelatine coated polystyrene surface was higher in comparison to the polymer surface. The chorioallantois membrane (CAM) assay was used as a sensitive assay to investigate the influence of angiogenesis in vivo. After 48 hours of exposure of the CAM to polymer samples no avascular zones, free of capillaries and/or thrombosis or hemorrhage were detectable. Considering the biofunctionality of our recently developed polymer in these experiments different surface modifications of the polymer are the topic of current investigation to support the biomaterial-microvasculature interactions in vivo.