Polystyrene surface coated with vitamin E modulates human granulocyte adhesion and MMP-9 release

Vitamin E (Vit.E, alpha-tocopherol) is a natural biological antioxidant and antinflammatory agent, which protects cells from the effects of free radicals and inhibits inflammation. For such properties Vit.E has been used to improve the biocompatibility of materials such as cellulose membrane for hemodialysis. In this study granulocytes adhesion and activation have been studied after contact with normal cell culture grade polystyrene (PS) and Vit.E-coated polystyrene (Vit.E 0.1 and 0.3% (v/v)) using optical microscopy, flow cytometry and substrate zymography. Vit.E increased the number of adherent granulocytes both at 0.1% (11470 +/- 1064 cells/cm(2), P < 0.01) and 0.3% ( 13706 +/-818) cells/cm(2), P < 0.001) concentration compared to normal PS (5529+/-692 cells/cm(2)). The morphology of granulocytes adherent to Vit.E-PS appeared lightly altered and no differences have been observed in their respiratory burst compared to control granulocyte, while matrix metalloproteinase 9 or gelatinase B (MMP-9) release and activation were increased compared to the normal PS samples. Our data indicate that Vit.E-coated surface induced an increase in granulocytes adhesion and MMP-9 release in the absence of the typical oxidative stress, hallmark of granulocytes activation. A possible explanation of the phenomenon is that Vit.E modifies the surface protein adsorption thus increasing cell adhesion and in turn MMP-9 releasing.