Mesoporous Potassium-Based Metal–Organic Framework as a Drug Carrier

To date, the number of reported mesoporous metal-organic frameworks (MOFs) remains limited. Herein, we report a novel mesoporous potassium-based MOF (K-MOF), designated as KMOF-1, whose precise structure was determined by using single-crystal X-ray diffraction. KMOF-1 used 18-crown-6 units as the organic linkers and potassium ions as the metal centers, forming a framework topological structure with interconnected four-membered rings. The specific surface area of the synthesized KMOF-1 was determined by the Brunauer-Emmett-Teller method, which showed a high specific surface area of 1034 m2/g. KMOF-1 was demonstrated to be a promising drug carrier, exhibiting encapsulation capabilities for various drugs and maintaining stability for a defined period under simulated physiological conditions. Using vascular endothelial growth factor (VEGF) aptamers as model drugs, we further confirmed the effective loading of VEGF aptamers in KMOF-1 (KMOF-1@VEGF) and the ability of KMOF-1@VEGF to release VEGF aptamers responsively in acidic environments. Additionally, in vitro studies showed that KMOF-1 protected VEGF aptamers from degradation by nucleases, allowing them to be effectively taken up by cells. This novel K-MOF, with its biocompatible metal centers, mesoporous channels, and demonstrated efficacy as a drug carrier, offers a significant advancement in developing MOF-based drug delivery systems.