The effect of the chemical structure of the phospholipid polymer on fibronectin adsorption and fibroblast adhesion on the gradient phospholipid surface

The interaction between biocomponents and the polyethylene (PE) surface mod ified with poly[omega-methacryloyloxyalkyl phosphorylcholine (MAPC)] was co nsidered taking into account the surface characteristics, i.e., density, mo bility, and orientation of the poly(MAPC). The PE surface, grafted graduall y with the poly(MAPC) was prepared by corona irradiation method. The amount of peroxide produced on the PE surface which was determined with 1,1-diphe nyl-2-picryl-hydrazyl, increased with an increase in the energy of the coro na. The surface density of the poly(MAPC) was increased with an increase in the amount of the peroxides produced by the corona irradiation. The orient ation and mobility of the poly(MAPC) grafted on the PE surface was evaluate d with 1,6-diphenyl-1,3,5-hexatriene, The orientation of the poly[6-methacr yloyloxyhexyl phosphorylcholine (MHPC)] which has six methylene chains betw een the phospholipid polar group and the backbone was higher than that of o ther poly(MAPC)s. The mobility of the poly(MAPC) decreased with an increase in the methylene chain length in the MAPC unit. The fibronectin adsorption on the gradient PE sheet grafted with poly(MAPC) was determined with enzyme-labeled immunoassay. The amount of adsorbed fib ronectin on the PE grafted with poly[2-methacryloyloxyethyl phospohorylchol ine(MPC)] and poly(MHPC) decreased with an increase in their surface densit y. Especially, the PE sheet grafted with the poly(MHPC) was effectively red uced compared with other poly(MAPC)s. On the poly[10-methacryloyloxydecyl p hosphorylcholine (MDPC)], there is a minimum amount of adsorbed fibronectin . The fibronectin adsorption pattern on the PE sheet grafted with poly(MAPC ) was quite different from the chemical structure of the MAPC unit. The hum an normal diploid fibroblasts (WI-38 cells) were cultured on the gradient P E sheet grafted with poly(MAPC) changing the concentration of seeded WI-38 cells. The adhesion behavior of the WI-38 cells was different depending on the concentration of the seeded WI-38 cells. When the concentration was low , the number of the adherent WI-38 cells had the same tendency as fibronect in adsorption. The gradient PE sheet grafted with the poly(MHPC) effectivel y reduced WI-38 cells adhesion even when the concentration of the WI-38 cel ls was high. The biocompatibility of polymer surfaces can be improved by hi ghly oriented phosphorylcholine group. (C) 1999 Elsevier Science Ltd. All r ights reserved.