A biocompatible biological component is provided comprising a membrane-mimetic
surface film covering a substrate. Suitable substrates include hydrated substrates, e.g. hydrogels which may contain drugs for delivery to a patient through the membrane-mimetic film, or may be made up of cells, such as
islet cells, for
transplantation. The surface may present exposed
bioactive molecules or moieties for binding to target molecules
in vivo, for modulating
host response when implanted into a patient (e.g. the surface may be antithrombogenic or antiinflammatory) and the surface may have pores of selected sizes to facilitate transport of substances therethrough. An optional hydrophilic
cushion or spacer between the substrate and the membrane-mimetic surface allows transmembrane proteins to extend from the surface through the hydrophilic
cushion, mimicking the structure of naturally-occurring cells. An alkylated layer directly beneath the membrane-mimetic surface facilates bonding of the surface to the remainder of the biological component.
Alkyl chains may extend entirely through the hydrophilic
cushion when present. To facilitate binding, the substrate may optionally be treated with a
polyelectrolyte or alternating
layers of oppositely-charged polyelectrolytes to facilitate charged binding of the membrane-mimetic film or alkylated layer beneath the membrane-mimetic film to the substrate. The membrane-mimetic film is preferably made by
in situ polymerization of
phospholipid vesicles.