Histological response to injected Polytef and Bioplastique in a rat model.

OBJECTIVE: To study, using a rat model, the tissue reaction in response to the migration of particulate plastics injected into the lungs and subcutaneous sites.

MATERIALS AND METHODS: A total of 50 rats were included in the study. Histological examination of 30 rats was carried out up to 6 months after the subcutaneous injection of 0.1 ml of either Polytef or Bioplastique. Specimens from a further 18 rats underwent histological examination up to 3 months after the intravenous injection of 0.01 ml of either Polytef or Bioplastique. Two rats were injected with normal saline to act as controls. Representative sections of multiple organs were taken from each animal.

RESULTS: No systemic migration from the site of initial implantation was detected. This may have been due either to the animal used or to the limited number of sections taken. However, the intravenously injected plastics were found adjacent to the pulmonary arterioles 3 months after injection. The histological reaction at the local injection and lung sites was similar, with the giant cells being larger and the degree of fibrosis greater for Bioplastique than for Polytef.

CONCLUSION: The histological reaction to Polytef and Bioplastique was similar in both the subcutaneous and lung sites. No migration or malignant change was seen.