Abstract <p>Multielectrode arrays are a kind of systems which have multiple electrodes on their surfaces to record or stimulate electrical activities in biological cells or tissues. In these systems, the electrodes are typically made of gold, titanium, platinum, carbon-based materials or stainless steel (SS) etc. Among these materials, SS has corrosion resistance, conductive, ease of fabrication and low-cost properties. However, biological properties of SS remain to be improved for its use as an electrode in neuroengineering applications. To enhance its biocompatibility, cellular and tissue interactions, SS could be modified to fabricate nanofeatured topographies on their surfaces. In this study, 65 and 100 nm homogenous nanoporous structures were obtained on the 316L SS surfaces via anodization process. Results indicated that having nanoporous structures on the surfaces (T-65 and T-100) significantly increased surface area compared to NA sample. It was observed that the nanoporous 316L SS surfaces enhanced ~2-folds more glioblastoma proliferation at 5 days in vitro and ~4-folds more neurite extension for T-65 surfaces. Therefore, fabricating nanoporous structures can improve biocompatibility, bioactivity and cellular interactions of the 316L SS surfaces and can be developed as low-cost and widely available electrodes for neuroengineering applications.</p>