Adsorption of collagen on model hydrophobic surfaces.

The change in interfacial tension with time for rat-tail tendon collagen adsorbing at the air, methylene iodide and isooctane interfaces has been followed by the pendant drop technique as a model for hydrophobic biomaterials. It is shown that the surface activity of tropocollagen at these three interfaces is less than that of albumin, gamma-globulin, serum of plasma, so that displacement of a preadsorbed plasma protein layer by tropocollagen molecules is energetically unfavourable and unlikely to occur. It is proposed that this may be one reason for the lack of interaction between hydrophobic soft tissue implants and their tissue capsules. It is then speculated that such interaction may require the development of biomaterials with a specific affinity for connective tissue components.