Nanoetched Stainless Steel Architecture Enhances Cell Uptake of Biomacromolecules

Nanotextured surfaces promote enhanced cellular adhesion and tissue integration in biomedical implants. These surfaces’ high aspect ratio nanoachitecture serves as an ideal interface between implant materials and host cells which is well-suited for localized therapeutic delivery. Despite their potential, nanotextured surfaces have not been widely applied for localized biomacromolecule delivery. We employed a low-cost, industrially relevant nanoetching process to modify the surface of biocompatible stainless and evaluated the feasibility of employing nanotextured SS316 (NT-SS316L) as a material for intracellular biomacromolecule delivery. We generated a functional coating of model biomacromolecule cargoes including superfolder green fluorescent protein (sfGFP) charge variants, cytochrome c and siRNA for intracellular delivery. Nanotextured surfaces enhanced cellular biomacromolecule uptake and delivered functional proteins and nucleic acids through energy-dependent endocytosis. Collectively, these findings indicate that NT-SS316L holds potential as a surface implant modification for localized drug delivery with many biomedical applications.