Utilization of Bulk RNA Sequencing for the Evaluation of Keratin Nanomaterials as a Coating for Percutaneous Devices

Despite advances in the design and protocols for maintaining the skin/device interface around percutaneous devices (PDs), no current strategy ensures the permanent attachment of peri-implant epithelial tissue to the device surface. Based on preliminary data, we hypothesized that PDs coated with keratin nanomaterials could provide a biochemically mediated surface that enhances epidermal cell adhesion and downgrowth. To test this hypothesis, fifteen Yucatan miniature pigs were each implanted with six percutaneous titanium devices, comprising three porous and three smooth devices, both with and without keratin coatings (Kerateine [iKNT] and Keratose [gKOS]). The pigs were sacrificed at 4, 8, and 16 weeks post-implantation. The devices and surrounding tissues were harvested and analyzed using histological and RNA sequencing techniques. Compared to smooth peri-implant tissue, porous peri-implant tissue showed a significant decrease in epithelial downgrowth, fibrous capsule thickness, and infections, alongside a significant upregulation of multiple immune marker genes, including IL12B. At the 16-week period, gKOS-coated surfaces demonstrated a more favorable wound healing response than iKTN-coated devices, with a reduction in granulation tissue area and a significant upregulation of several keratin genes related to differentiation. Among the combinations of surface types and coatings studied, the porous gKOS-coated device produced the most favorable wound healing response. Yucatan minipigs were implanted with six sterile percutaneous deviceses with smooth subdermal disks (1 uncoated control, 1 iKTN-coated, and 1 gKOS-coated) and three additional porous subdermal disks (1 uncoated control, 1 iKTN-coated, and 1 gKOS-coated) under their dorsal skin. Granulation tissue was harvested at the planned necrospy for each pig for RNA sequencing.