Human fibroblast attachment on fibrous parylene-C thin-film substrates

Although the polymeric form of parylene-C is used in many medical devices, the mechanistic nature of cellular attachment to polymeric parylene-C is not clear. We examined the effects of (i) substrate morphology, (ii) surface wettability and (iii) presence of serum proteins on fibroblast attachment. A physicochemical vapor deposition technique was implemented to deposit flat parylene-C substrates as well as fibrous substrates of three different morphologies: slanted columnar, chevronic and chiral. Flat parylene-C surfaces were moderately hydrophobic while fibrous substrates were superhydrophobic. Pretreatment with oxygen plasma changed the substrate surfaces from hydrophobic to superhydrophilic. The attachment efficiency of human fibroblast cells to the flat and three fibrous thin-film parylene-C substrates was investigated. Fibroblast attachment was better on fibrous substrates than on flat substrates, and oxygen plasma pretreatment facilitated fibroblast attachment on all four morphologies. Serum proteins also facilitated cell attachment on all substrates. The combination of oxygen plasma pre-treatment and serum proteins increased fibroblast adhesion in an additive manner on flat, but not on fibrous parylene-C substrates. The morphology of cell–substrate interactions differed between fibrous and flat parylene-C substrates.