Polyetherimide as biomaterial: preliminary in vitro and in vivo biocompatibility testing

During the last few years, on the basis of their physico-chemical characteristics, thermoplastic materials, already used in several advanced industries, have become very attractive candidates for biomedical applications as matrix for composite femoral stems and bone plates. In the present study, the biocompatibility of a thermoplastic material, polyetherimide (PEI), was investigated both in vivo, and in vitro. Our results show that PEI did not elicit any toxic response in cell culture testing. It was possible to grow on PEI surfaces not only 3T3 fibroblasts but also human endothelial cells (HEC) from human umbelical cord, with no apparent deleterious effects on the cell viability. The attachment, spreading, and growth of cells on PEI material was followed with respect to time. Both the number of adhering HEC, and the spreading area of individual cells, increased as a function of time. The hydrogen peroxide-sensitive dye DCFH-DA was used to examine the functional activity of cells adherent to PEI or control material implants. PEI material did not induce significant DCFH oxidation until day 14, when levels of DCFH oxidation were significantly higher than observed with PDMS negative control, but lower than those observed on Pellethane positive control.