THE CHEMILUMINESCENCE RESPONSE OF NEUTROPHILS ON POLYMER SURFACES MADE BY GLOW-DISCHARGE PLASMA POLYMERIZATION

Polypropylene tubes were coated with different polymers made by glow d ischarge plasma polymerization. Isolated human blood neutrophils were allowed to interact with the polymer surface and the chemiluminescence response of the cells was recorded as a measure of oxidative activati on. The polymers represented surfaces that differed markedly with resp ect to charge, hardness, and wettability. We found that all polymers s timulated the chemiluminescence response in neutrophils differently; w hen preincubation with human serum albumin (HSA) there was a general r eduction of the chemiluminescence response particularly on one of the positively charged surface 1, 2-diamino-cyclohexane (DACH). Addition o f a soluble stimulus, the chemoattractant formylmethionyl-leucylphenyl alanine (FMLP), to the cells caused a dramatic increase in the respons e on one of the hydrophobic surface hexamethylene-isiloxane (HMDSO). H owever, there was also a pronounced reduction in the response on polym ers with acrylic acid (AA). The response was normalized after addition of HSA. Taken together, the chemiluminescene response of the neutroph ils interacting with the polymer surfaces differed with regard to the type of surfaces. When HSA and FMLP were added a larger difference in the response was found. Our results showed that the activation of huma n neutrophil granulocytes influenced by different polymer surfaces, fo llowed unspecific different patterns which were someway related to the specific characteristics of the polymer and from this point we came t o similar conclusions made by Kaplan et al. (J. Biomater. Res. 28, 377 (1994)), that it is difficult to extrapolate any activation mechanism s from one material to another. The reproducibility of the reaction pa tterns, the importance of neutrophil activation, and the relative simp licity of the method indicates, however, that the mechanisms of neutro phil activation at biomaterial surface is well worth further research.