Nickel-free porous stainless-steel nanocomposites for versatile biomedical applications: fabrication, characterization, and evaluation of electrochemical and immunogenicity detection

This study focuses on the development of nickel-free stainless-steel nanocomposites with porosities tailored for surgical implants and biological applications. Alloy F2581 (Fe–17Cr–10Mn–3Mo–0.4Si–0.5N–0.2C wt%), modified by replacing Mo with metals such as Al, Cu, Ti, and W, was successfully fabricated via a solid-state reaction method. X-ray diffraction analysis revealed a significant alteration in the crystal phase, accompanied by the formation of nanostructures, including nanowires, square nanotubes, wave-like configurations reminiscent of a growing clover farm, and nanofibers. The particle sizes of these structures were determined to be 73, 27.2, 76 and 98.5 nm for Al, Cu, Ti, and W ions, respectively, indicating a distribution of nanopores. Biological evaluation of adult male Albino rats after exposure to single intraperitoneal doses of various concentrations (10, 20, and 50 mg kg⁻¹ wt%) were assessed with testing alloys (Cu, Al, W, and Ti, respectively). Over a subacute period lasting 60 days, a comprehensive evaluation of biological responses, including hepatic function, renal performance, oxidative and/or nitrosative stress parameters, and the levels of serum immune modulators was conducted. Notably, low doses elicited negligible immune responses, higher doses, barring copper, induced notable reactions. Interestingly, aluminum demonstrated optimization within biological settings, alongside titanium and tungsten. These findings highlight the applicability of copper and tungsten for medical implantation and biological applications under controlled circumstances, particularly at lower dosage levels.