CYTOCOMPATIBILITY OF 2 SEGMENTED BIOMEDICAL POLYURETHANES

In this work the proliferation of mitogen-activated human T lymphocyte s, and human endothelial cells (HEC) adhesion and growth have been eva luated in vitro with two segmented polyurethanes (SPUs) having differe nt chemical structure: Pellethane 2363-80A, a poly-ether-urethane, and Corethane 55D, a polycarbonate-urethane. The effect of the two SPUs o n phytohemoagglutinin (PHA)-induced T-cells proliferation was analysed by evaluating both morphological changes of the lympho-monocyte syste m with scanning electron microscopy (SEM), and the perturbation of cel l cycle progression with a cytofluorimetric technique. Results showed that, although the PHA stimulation of T-cells cultured on Corethane wa s sufficient to induce entry into the cell cycle, as evidenced by an i ncrease in RNA content, the DNA synthesis appeared similar to that of unstimulated cultures. On the other hand, there was a significant incr ease of the DNA and RNA content in the culture performed in the presen ce of Pellethane, as in the case of PHA-stimulated control cultures. M oreover, in comparison with Pellethane, a strong decrease in monocyte attachment and spreading was observed on Corethane; with lymphocytes s cattered around the monocytes, and not attached to them as in the case of Pellethane. In the experiment with HEC, the cells were directly se eded on the materials, and the number of cells attached after 4 and 72 h culture was then evaluated, the former reading being a measure for cell adhesion, the latter indicating the capacity of the cells to prol iferate. Although both SPUs allowed a HEC adhesion lower than the posi tive control, it was possible to confirm that Pellethane well supports cell proliferation, whereas Corethane is less prone to promote cell g rowth