PEDOT:PSS films are being extensively explored for the treatment of visual impairment, particularly relating to amelioration or restoration of retinal function. However, the action of PSS severely hampers the biocompatibility and integrity of the resultant implantable biodevices (Supplementary section S8). In this context, the biocompatibility of PEDOT thin films electrosynthesised at the ITIES was compared with that of a drop cast PEDOT:PSS film using an adherent cell line derived from normal human retina pigment epithelium (hTERT RPE-1), see Fig. . Following 48 hours of cell growth on each film, marked differences were observed in hTERT RPE-1 cell growth dynamics (Fig. ). Overall, in the presence of PEDOT thin films, cells exhibited a greater degree of proliferation and showed a stretched morphology, associated with actin bundle stress fibre formation, alluding to the more biocompatible nature of PEDOT versus PEDOT:PSS (Fig. ). These data re-enforce the challenges of using PSS at bio-interfaces and differentiate our investigations from many evaluating PEDOT:PSS in cell culture, where lack of obvious cytotoxicity is incorrectly construed as high biocompatibility. Next, each film was evaluated for suitability of active biomolecule incorporation. Collagen was selected as an active biomolecule due to its known influence on