Effective loading of cisplatin into a nanoscale UiO-66 metal-organic framework with preformed defects

Defects within the nanoscale UiO-66 metal-organic framework (MOF) are created to lock a hybrid phosphonoacetate ligand through Zr-O-P linkages, leaving the carboxyl group free to anchor cisplatin prodrug cis, cis, trans-[Pt(NH3)(2)Cl-2(OH)(2)]. A drug loading of 256.5 mg g(-1) (25.7 wt% based on cisplatin) was achieved with a Zr-6:Pt:P ratio of 1.5:1:1, which surpasses defect-free UiO-66 and several other MOF carriers. This framework exhibited a burst release of its payload in PBS solution in the first 2 h, releasing 71% of the drug, including a 50% payload release in less than 1 h. This work demonstrates that MOF defects can be intentionally engineered to achieve a high drug loading, and serves as an alternative to drug encapsulation using the pore void and through the association of the functionalized ligand.