BIOCOMPATIBILITY OF EIGHT POLY(ORGANOPHOSPHAZENES)

Eight poly(organophosphazenes) [R 2 P = N) x with widely different physical and mechanical properties were cast into films and implanted intramus cularly into rats for periods of 7 and 28 days. Silicone sections of the, same shapes and sizes were similarly implanted as controls. The tissue implant sites were excised and examined macros copically and micros copically. Each implant site was characterized for cell types, total cellular density and thickness of cellular reaction. The examinations revealed no signs of adverse tissue reaction. Correlation of the data, according to the method of Sewell, willand and Craver, showed a remarkably similar tissue response to each of the phosphazenes, irrespective of the organo substituents, and to the silicone controls. For each material, the biological toxicity was classified as slight.