Interaction of plasma proteins with commercial protein repellent polyvinyl chloride (PVC): a word of caution.

Protein adsorption onto polymers remains a problem. In recent years, several protein-repellent PVC tubings have been developed. Although several studies report the interaction between plasma coagulation proteins and PVC, few address the interaction with other plasma proteins. Two commercial brands of untreated medical grade PVC tubing, phosphorylcholine-coated PVC tubing, triblock-copolymer (polycaprolactone-polydimethylsiloxane-polycaprolactone)-treated PVC tubing and poly-2-methoxyethylacrylate (PMEA)-coated tubing were exposed for 60 minutes to human plasma. A broad spectrum of plasma proteins was found on all tubing. The adsorbed albumin to total protein ratio is lower than the similar ratio in plasma while alpha1 and alpha2 globulins are over-represented in the protein spectrum. On PMEA tubing, not only alpha globulins, but also beta and gamma globulins, are found in high concentrations in the adsorbed protein. PMEA tubing and uncoated PVC tubing of brand B had a higher amount of protein adsorbed compared against all other tubing (p < 0.05). There were no statistical differences in protein adsorption between the triblock-copolymer-treated tubing, the phosphorylcholine-coated tubing and the uncoated PVC tubing of brand A. The average thickness of the protein layer was 23 nm. Plasma protein adsorption still exists on uncoated and protein-repellent tubing and can initiate a systemic inflammatory reaction.