C G Gölander | PubMed Health

PubMed1992

RF-plasma-modified polystyrene surfaces for studying complement activation.

Five different plasma modified surfaces were made for studying different aspects of biocompatibility. These surfaces were: 1,2-diaminocyclohexane (DACH), acrylic acid (AA), Hydroxyethylmethacrylate (HEMA), methane and hexamethylene-disiloxane (HMDSO). In addition a polyethylene-glycol (PEG) was made by grafting aldehyde functional PEG to the DACH surface. PEG and HMDSO which are the most hydrophilic and the most hydrophobic surface shows the lowest amount of adsorbed protein of the three proteins studied here (albumin, IgG and C3). Methane, HMDSO and HEMA was found to activate via the classical (complement activation) pathway while the others activated via the alternative pathway.

Adsorption↗

PubMed1990

Characterization of hydrophobicity gradients prepared by means of radio frequency plasma discharge.

A hydrophobicity gradient was created by gradually exposing a polydimethylsiloxane film to a radio frequency glow discharge in an oxygen atmosphere. A change in contact angle from 100 to 0 degrees was measured along the gradient surface by means of the Wilhelmy balance technique. The gradient surface was characterized by studying the adsorption from single protein solutions of human albumin, IgG and fibrinogen using total internal reflectance fluorescence (TIRF). Generally, adsorption values similar to monolayer capacities were measured on the hydrophobic side. The adsorption decreased towards the hydrophilic end in correspondence with the change in contact angle. The displacement of proteins with a ethylene oxide-propylene oxide copolymer (EO70PO100EO70) was higher on the hydrophobic side than on the hydrophilic side. Albumin showed an adsorption peak in the wetting transition region, indicating a very strong affinity.

Adsorption↗