A modified HET–CAM approach for biocompatibility testing of medical devices
The implantation of new biomedical devices into living animals without any previous toxicity or biocompatibility evaluation is possible under current legislation. The HET–CAM (Hen Egg Test–Chorionallantoic Membrane) test offers a partially immunodeficient, borderline in
vitro/in vivo test system that allows the simulation of transplantation experiments to obtain biocompatibility data prior to animal testing. A collagen type I/III scaffold, designed for tissue regeneration, was tested for angiogenetic properties and biocompatibility patterns. A significant
angiogenetic stimulus caused by the collagen scaffold material was observed. Altering biocompatibility patterns by incubation with the potentially hazardous chemicals acridine orange and ethidium bromide led to severe vessel thrombosis and a foreign body tissue response. CAM testing of biomaterials
and tissue engineered products allows selection of the most suitable biomaterial and the elimination of unsuitable materials from animal experiments, leading to a refinement of testing procedures and a reduction in the number of animals required for biocompatibility testing.