Nanometric Faujasite (FAU) Zeolite Ion-Exchanged With Metal Ions for Hemostatic and Antimicrobial Applications: A Thromboelastographic and Microbiological Study.

Abstract

Integrating antimicrobial functionality with the intrinsic clot-promoting properties of zeolites represents a promising strategy for next-generation wound-care materials, where rapid hemorrhage control must be coupled with infection prevention. Here, we investigate nanocrystalline Faujasite (NanoFAU) and its ion-exchanged derivatives to elucidate how extra-framework cation identity governs the balance between hemostatic and antimicrobial performance. NanoFAU samples exchanged with Ag⁺, Ba^{2 +}, Ca^{2 +}, and Mg^{2 +} were comprehensively characterized by XRD, SEM/HRTEM/EDS, AFM, BET surface area analysis, ^{2 9}Si MAS NMR and FT-IR spectroscopy, confirming preservation of the FAU framework and successful cation substitution. All ion-exchanged materials exhibited isoelectric points below physiological blood pH, consistent with negatively charged, procoagulant surfaces. Thromboelastography revealed that Ca^{2 +}-exchanged NanoFAU (NanoFAU-Ca) achieved the most pronounced hemostatic response (R = 1.1 min; K = 1.2 min; MA = 60.3 mm), whereas Ag⁺-exchanged NanoFAU (NanoFAU-Ag) provided strong antimicrobial activity against Staphylococcus aureus (ATCC 25923) and Candida albicans (ATCC 90028), displaying bactericidal and fungistatic effects, respectively. Importantly, NanoFAU-Ag maintained cell viability above the ISO 10993-5 cytotoxicity threshold in HaCaT keratinocytes. These findings demonstrate that ion exchange enables rational tuning of NanoFAU to achieve complementary hemostatic and antimicrobial functionalities while preserving cytocompatibility, establishing NanoFAU as a versatile inorganic platform for multifunctional wound management and supporting future in vivo evaluation.