Assessing the Chemical Stability and Cytotoxicity of Electrodeposited Magnetic Mesoporous Fe-Pt Films for Biomedical Applications.

The development of feasible micro/nanoplatforms for various biomedical applications requires holistic research that explores scalable synthesis and design pathways and imposes an interdisciplinary integration of materials science, physical, medical, chemical, and biological knowledge. Thanks to their unique characteristics (i.e., structure, large specific surface areas, tuneability, versatility, and integrity), mesoporous materials have emerged as potential candidates for being part of micro/nanoplatforms for therapeutic, monitoring, and diagnostic applications. In this context, Fe-Pt mesoporous materials are excellent candidates to be part of biomedical micro/nanoplatforms, thanks to their chemical nature, structure, and magnetic properties, which endow them with magnetic locomotion, high cargo capability of therapeutic agents inside the mesoporous cavity, and large surface area for surface functionalization. However, the chemical stability in biological media and cytotoxicity of the Fe-Pt mesoporous material (without considering the effects of architecture and shape) are pivotal elements that determine the suitability of these materials for biomedical applications. This work demonstrates the following: (i) the potential of electrochemical deposition, based on the use of block copolymer micellar solutions as electrochemical media, as an easy, inexpensive, and scalable strategy to synthesize mesoporous Fe-Pt components with tunable chemical composition, porosity, magnetism, and shape (in this case films, but other architectures like nanowires can be easily fabricated using simultaneously hard templates); (ii) the excellent corrosion stability, which is comparable to bulk Au, and minimal chemical dissolution in biological media after 160 h of immersion (∼0.88% of Fe and ∼0.0019% of Pt), which confirms the robustness of Fe-Pt; and (iii) negligible cytotoxicity on HaCaT cells (human immortalized keratinocytes), which reinforces the biocompatibility of Fe-Pt mesoporous structures. Also, the presence of Fe-Pt mesoporous films seems to induce a slight increase in cell viability. These results confirm the biocompatibility of Fe-Pt mesoporous films, making them suitable for biomedical applications.