Highly flexible and controllable hierarchical MOF membrane for efficient drug release

An active wound dressing that is biomechanically and biochemically effective is essential for wound care and skin tissue regeneration. Despite its importance, issues persist with mechanical compatibility and drug release control, restricting the optimal use of existing dressings. In this work, we present a simple approach using a poly (vinylidene fluoride) (PVDF) substrate containing zeolitic imidazolate framework (ZIF-8) seeds of different sizes to start the precise development of a highly flexible metal-organic framework membrane with a consistent honeycomb structure, suitable for drug loading and release. With the embedded seeds serving as a control center, the honeycomb membrane formed features pore openings ranging from 0.7 to 3 µm. These adjustable microscale pores, combined with the intrinsic nanopores in ZIF-8, facilitate efficient loading of the anti-inflammatory drug curcumin (CCM) and enable its rapid and controlled release for antibacterial activity and cell growth. Among these, the 0.7-µm honeycomb membrane produced on the 40-nm seed showed a 2-fold increase in cell proliferation compared with the honeycomb membrane (equal to the bare PVDF substrate). Furthermore, it displayed 5 and 2.4 times greater antibacterial activity against Staphylococcus aureus and Escherichia coli than the substrate. These results are attributable to the balanced influence of CCM and Zn2+ release properties from such ideal pore geometries. The controllable and hierarchical pore-arrayed membrane boasts unique characteristics that make it a promising option for wound healing. Additionally, it offers valuable insights for the design of future biomedicine applications.