A Large Capacity Cationic Metal-Organic Framework Nanocarrier for Physiological pH Responsive Drug Delivery.

A nanoscale cationic porous drug carrier ZJU-101 (ZJU = Zhejiang University), synthesized by the solvothermal method to get the crystal size of ∼300 nm, was used to load diclofenac sodium, an anionic drug. This positively charged host materials showed a large loading capacity of diclofenac sodium (∼0.546 g/g) through ion exchange and penetration procedures. The drug delivery in the inflamed tissues (pH = 5.4) exhibited a more effective release in comparison with that in the normal tissues (pH = 7.4), demonstrating a physiological pH responsive drug release. This discriminating drug release process was controlled by anion exchange between anions in phosphate buttered saline (PBS) and coordinated/free diclofenac anions.