Dual-Stimulus-Triggered Programmable Drug Release and Luminescent Ratiometric pH Sensing from Chemically Stable Biocompatible Zinc Metal-Organic Framework

Metal-organic frameworks (MOFs), as drug delivery carriers, with high loading capacity and controllable release behavior can provide a more efficacious therapy in cancer treatments. In our work, a novel biocompatible zinc MOF Zn-cpon-1 with the (3,6)-connected rtl 3D topological network was designed and synthesized via employing ClO₄^- anion as template. The optically and chemically stable Zn-cpon-1 could be verified as a pH-responsive dual-emission platform and excellent drug delivery carrier with higher 5-fluorouracil (5-FU) (44.75 wt %) loading behavior than 6-mercaptopurine (6-MP) (4.79 wt %) ascribed to the influence of size and shape matching. The multiple interactions between Zn-cpon-1 and 5-FU drug molecules have been discussed and evidenced, which could be quantitatively estimated via the rate constant related to the topological structure. Specially, the gust release behavior of 5-FU@Zn-cpon-1 microcrystal was described and programmed via the Weibull distribution model and could be dual-triggered by the temperature and pH stimulus. This study illustrates that the Zn-cpon-1 without any postmodification performs a favorable potential of being used as biomedical drug delivery alternative carriers in effective drug payload, flexible release administration, and superior dual-stimuli responsiveness.