MOF × Biopolymer: Collaborative Combination of Metal–Organic Framework and Biopolymer for Advanced Anticancer Therapy

Metal–organic framework (MOF) nanoparticles with high porosity and greater tunability have emerged as new drug delivery vehicles. However, premature drug release still remains a challenge in the MOF delivery system. Here, we report an enzyme-responsive, polymer-coated MOF gatekeeper system using hyaluronic acid (HA) and PCN-224 nanoMOF. The external surface of nanoMOF can be stably covered by HA through multivalent coordination bonding between the Zr cluster and carboxylic acid of HA, which acts as a gatekeeper. HA allows selective accumulation of drug carriers in CD44 overexpressed cancer cells and enzyme-responsive drug release in the cancer cell environment. In particular, inherent characteristics of PCN-224, which is used as a drug carrier, facilitates the transfer of the drug to cancer cells more stably and allows photodynamic therapy. This HA-PCN system enables a dual chemo and photodynamic therapy to enhance the cancer therapy effect.