NONSPECIFIC INTERACTIONS BETWEEN HEPARIN AND POLY-L-LYSINE SURFACES

The surface force apparatus has been used to study the force law betwe en mica surfaces modified with the biopolymers heparin and poly-L-lysi ne by direct adsorption from solution. Between identical surfaces the interactions were well described by the DLVO theory for repulsive doub le-layer overlap. Between dissimilar surfaces, strong attractive force s were measured which were consistent with the Hogg-Healy-Fuerstenau a pproximation to the Poisson-Boltzmann distribution for asymmetric doub le layers, suggesting a non-specific electrostatic basis for the measu red long-range forces.