Tumorigenicity of poly-L-lactide (PLLA) plates compared with medical-grade polyethylene.

Abstract

Poly-L-lactide (PLLA) plates, 20 x 10 x 1 mm in size, with flat surfaces, were implanted into 50 young male Wistar rats subcutaneously, and the incidence of tumors for 2 years under specific pathogen-free (SPF) conditions was evaluated. Tumors arose in 22 rats (at the implant sites in 20, and distant from the implantation site in 2). As a control, plates of medical-grade polyethylene of the same shape were implanted into 50 rats. Tumors appeared in 23 of these rats (21 at the sites of the plates, and 2 ectopically). In 30 rats given sham operations, no tumors appeared in the 2 year observation period. Histologically, all the tumors were mesenchymal malignant tumors resembling fibrosarcoma or malignant fibrous histocytoma (MFH) in humans. In 6 of the PLLA tumors and 3 of the PE tumors, bone formation was observed. There was no significant difference between the incidence of tumors caused by PLLA plates and that of tumors caused by medical-grade polyethylene plates. Macroscopically, PLLA plates retained their initial shape for 2 years. Scanning electron microscopy revealed small holes on the surfaces of the plates, and their molecular weight was reduced to 8% of the initial value.

• Authors: T Nakamura, Y Shimizu, N Okumura, T Matsui, S H Hyon, T Shimamoto
• Journal: Journal of biomedical materials research (J Biomed Mater Res) Vol. 28 Issue 1 Pg. 17-25 (Jan 1994) ISSN: 0021-9304 [Print] United States
• PMID: 8126025 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Biocompatible Materials
• Carcinogens
• Polyesters
• Polyethylenes
• poly(lactide)

Topics

• Animals
• Biocompatible Materials (toxicity)
• Body Weight (drug effects)
• Bone Neoplasms (chemically induced, pathology)
• Carcinogens (toxicity)
• Fibrosarcoma (chemically induced, pathology)
• Histiocytoma, Benign Fibrous (chemically induced, pathology)
• Male
• Microscopy, Electron, Scanning
• Molecular Weight
• Osteosarcoma (chemically induced, pathology)
• Polyesters (toxicity)
• Polyethylenes (toxicity)
• Prostheses and Implants (adverse effects)
• Rats
• Rats, Wistar