Zirconium-Based Nanoscale Metal–Organic Framework/Poly(ε-caprolactone) Mixed-Matrix Membranes as Effective Antimicrobials

Metal-organic framework (MOF)-polymer mixed-matrix membranes (MMMs) have shown their superior performance in gas separation. However, their biological application has not been well-explored yet. Herein, a series of zirconium-based MOF MMMs with high MOF loading and homogeneous composition have been prepared through a facile drawdown coating process. Poly(ε-caprolactone) (PCL) has been selected as a binder for its good biocompatibility and biodegradability. Zr-MOF nanoparticles, UiO-66, and MOF-525, have been utilized as "filler" because of their superior chemical stability, good biological safety, and versatile functions. Both UiO-66/PCL MMMs and MOF-525/PCL MMMs have a uniform appearance even at the highest loading of 50 wt % for UiO-66 and 30 wt % for MOF-525, respectively. The integrity of pore structures of UiO-66 within MMMs maintains well, which is evidenced by dye separation. All obtained MMMs possess good biocompatibility and mechanical property. Upon irradiation, MOF-525/PCL MMMs generate reactive oxygen species and serve as effective antibacterial photodynamic agents against Escherichia coli. This study offers an alternative system for forming homogeneous MOF/polymer MMMs and represents the first example of exploiting hybrid MMMs for biological applications.