Solid surface chemical and physical effects on the adsorption of recombinant Factor VIII.

The adsorption of a recombinant Factor VIII to silica surfaces coated to present different hydrophilic/hydrophobic, electrostatic and steric characteristics was monitored in situ, with ellipsometry. rFVIII adsorption affinity was high for hydrophobic surfaces and hydrophilic, charged surfaces. A lower affinity was recorded between rFVIII and a neutral hydrophilic surface, with substantial reduction in rFVIII adsorption to electronically neutral surfaces presenting pendant poly[ethylene oxide] chains.

Nisin antimicrobial activity and structural characteristics at hydrophobic surfaces coated with the PEO-PPO-PEO triblock surfactant Pluronic F108.

The antimicrobial peptide nisin has been observed to preferentially locate at surfaces coated with the poly[ethylene oxide]-poly[propylene oxide]-poly[ethylene oxide] (PEO-PPO-PEO) surfactant Pluronic F108, to an extent similar to its adsorption at uncoated, hydrophobic surfaces. In order to evaluate nisin function following its adsorption to surfaces presenting pendant PEO chains, the antimicrobial activity of nisin-loaded, F108-coated polystyrene microspheres and F108-coated polyurethane catheter segments was evaluated against the Gram-positive indicator strain, Pediococcus pentosaceus. The retained biological activity of these nisin-loaded layers was evaluated after incubation in the presence and absence of blood proteins, for contact periods up to one week.

Nisin adsorption to hydrophobic surfaces coated with the PEO-PPO-PEO triblock surfactant Pluronic F108.

The adsorption and elution of the antimicrobial peptide nisin at hydrophobic, silanized silica surfaces coated with the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactant Pluronic F108 were measured in situ, with ellipsometry. While such layers are known to inhibit protein adsorption, nisin was observed to adsorb in multilayer quantities, to an extent similar to its adsorption at uncoated, hydrophobic surfaces. The rates of nisin adsorption and elution were generally slower at F108-coated surfaces.