The biocompatibility of a novel polyether ether ketone (PEEK) stoma device with human epidermal keratinocytes

Surgical stomas are essential interventions for many medical conditions, however, can create physical complications, such as peristomal skin irritation. Medical stoma devices (MSD) are a potential treatment to mitigate such complications. Polyether ether ketone (PEEK) is a promising material for implantable MSD due to its established biocompatibility within orthodontic and orthopaedic applications. However, its cytocompatibility with human epidermal keratinocytes has not been evaluated according to ISO 10993-5:2009 guidelines. This study aimed to assess the biocompatibility of a novel PEEK MSD with human keratinocytes (HaCaT cells). Cells were cultured on discs of PEEK, surface-modified PEEK (m-PEEK), and polylactic acid (PLA). Surface topography was investigated via SEM to assess surface roughness (S_a, S_z), and water contact angle (WCA). m-PEEK demonstrated increased S_a and WCA compared to PLA and unmodified PEEK. Cell proliferation and viability were evaluated using CyQUANT™ and AlamarBlue™ assays and no significant differences were observed among PLA, PEEK, and m-PEEK. Cell adhesion was assessed using an adhesion assay, with m-PEEK demonstrating significantly higher cell adhesion than PLA (p < 0.05), with cell attachment confirmed via SEM imaging. Cytokine analysis of supernatants using Luminex Immunoassay revealed two (IL-1α and IL-6) of six cytokines outlined in the ISO 10993-20:2006 guidelines were elevated in the presence of PEEK at 72 h. These findings suggest that PEEK is non-cytotoxic and biocompatible with human keratinocytes. Further studies are warranted to assess PEEK's compatibility with colonic cells, 3D skin models, and in vivo systems (including for chronic inflammatory responses) for MSD applications.