Delayed in vitro immune response to long-term intraperitoneal polymer implant in mice

This paper presents an original experimental procedure designed to evaluate, by a two step in vivo/in vitro combination, the long-term biocompatibility of synthetic materials developed for clinical applications. The efficacy of the test is illustrated by the experimental results obtained with various materials currently used in medicine (Dacron, RCH) and also with three recently synthesized compounds. In the first step of the procedure, the sample was grafted for at least 5 months in the peritoneal cavity of mice, allowing the possible development of delayed sensitization. In the second step, this sensitization was detected by an in vitro test, the Lymphoblastic Transformation Test (LTT), adapted for this new purpose. On the basis of this experiment, the 5 polymers tested were classified into 2 groups: one group did not significantly differ from the control, and the other had a significantly higher incidence of sensitization. As these results were in agreement with the known biocompatibility of these polymers, they demonstrate the validity of the test to classify new polymers.