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.