Metallic Oxide-Induced Self-Assembly of Block Copolymers to Form Polymeric Hybrid Micelles with Tunable Stability for Tumor Microenvironment-Responsive Drug Delivery

Since block copolymers are able to self-assemble into various polymeric architectures, it is intriguing to explore a unique self-assembly strategy for polymers. Two different metallic oxides [manganese dioxide (MnO2) and zinc oxide (ZnO)] are displayed herein to demonstrate this self-assembly mechanism of polymers. In situ generation of metallic oxides induces self-assembly of block copolymers to form polymeric hybrid micelles with tunable stability in aqueous solutions. These final ZnO-cross-linked polymeric micelles exhibited a high drug loading capacity of 0.41 mg mg(-1) toward doxorubicin (DOX), whereas DOX-loaded ZnO-cross-linked polymeric micelles could be broken down into Zn2+ and polymer scraps, which facilitated drug release in tumor microenvironments. Both in vitro and in vivo investigations showed that the drug-loaded ZnO-cross-linked polymeric micelles effectively suppressed tumor growth. Accordingly, the present study demonstrates a novel strategy of polymer self-assembly for fabricating polymeric architectures that can potentially provide insight for developing other polymeric architectures.

Automated summary

This study demonstrates a unique self-assembly strategy for polymers by utilizing different metallic oxides to induce the self-assembly of block copolymers into polymeric hybrid micelles with tunable stability. The final ZnO-cross-linked polymeric micelles show a high drug loading capacity and efficient drug release in tumor microenvironments, effectively suppressing tumor growth in both in vitro and in vivo investigations. The findings provide insights for developing other polymeric architectures for various applications.