Sustainable silver-integrated ZSM-5 coating on AISI 316 L implants: a multifunctional platform for controlled cisplatin delivery and antifungal activity

The study investigates the effect of a multifunctional, green-synthesized silver zeolite (Ag-Zeo) coating on AISI 316 L stainless steel, fabricated using an immersion assisted hydrothermal technique, for potential applications in bone tumor treatment and antifungal therapy. The formation of the Mobil-type five zeolite (MFI) phase with a hierarchical pore structure, along with the incorporation of silver into the green zeolitic framework, was characterized using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, diffuse reflectance UV-visible (DRS UV-vis) spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy. XRD analysis confirmed the crystalline ZSM-5 (Zeolite Socony Mobil–5) structure, while BET analysis revealed a surface area of approximately 474 m 2 /g and an average pore size of 2.24 nm. Scanning electron microscopy-Energy dispersive X-ray (SEM) and transmission electron microscopy (TEM) analyses revealed the formation of micron-sized zeolitic structures and a homogeneous deposition of the Ag-Zeo coating as a thin film on stainless-steel substrate. EDX elemental mapping further demonstrated the uniform distribution of Ag Si, Al, and O throughout the coating. The corrosion resistance of the coated implant was investigated using DC polarization measurements. The Ag-Zeo coated stainless steel demonstrated stable behavior with a corrosion-resistive interface. Furthermore, the Ag-Zeo coating exhibited pH-responsive release of the chemotherapeutic agent cisplatin (CP) under acidic tumor-mimicking conditions (pH 5.6). The coating was also tested for its antibiofilm efficacy against implant-associated fungi, specifically Candida albicans, and showed significant anti-adhesion activity in adhesion assays.