Hierarchically porous MOF-based microneedles for glucose-responsive infected diabetic wound treatment

Abstract

Elaborately designed stimuli-responsive antibacterial systems are highly desirable for infected diabetic wound treatment. Herein, hierarchically porous metal–organic framework (MOF)-based glucose-responsive microneedles (MNs) were designed for painless transdermal wound treatment. For the first time, a hierarchically porous MOF was applied for consuming the surplus glucose to protect infected diabetic wounds from bacterial infection. Through one-pot synthesis, glucose oxidase (GOx) was firstly encapsulated into a Fe-doped zeolitic imidazolate framework (ZIF), and based on a properly controlled tannic acid (TA) etching process, the hierarchically porous MOF (GOx@Fe-ZIF-TA) was constructed afterwards. GOx encapsulated in GOx@Fe-ZIF-TA could consume surplus glucose in infected diabetic wounds to yield gluconic acid and H₂O₂. The latter could be catalyzed by Fe(II) to generate antibacterial ˙OH, which would not result in antimicrobial resistance. The as-obtained hierarchically porous MOF revealed satisfactory glucose-responsive antibacterial activity, and the hierarchically porous MOF-based MNs showed enough stiffness for penetration. This study offers a new strategy, using hierarchically porous enzyme-loaded MOFs as depots to integrate with MNs, for designing stimuli-responsive transdermal systems for the treatment of infected diabetic wounds and other diseases.