Enhancing Microwave Dynamic Effects via Surface States of Ultrasmall 2D MOF Triggered by Interface Confinement for Antibiotics-Free Therapy

Microwave (MV)-trigged dynamic therapy based on MV-responsive materials is promising for treating deep infection diseases that cannot be effectively treated by antibiotics, like life-threatening osteomyelitis. Surface states of materials affect the generation of free charges under the excitation source with energy less than the band gap, consequently influencing the MV dynamic effects. Herein, an MV responsive system with interface confined 2D metal-organic framework (2D MOF) on oxidized carbon nanotube (CNT) is prepared, in which the ultrasmall Cu-based 2D MOF possesses sufficient surface/interface defects, endowing the system a large number of surface states. Under MV irradiation, the synthesized CNT-2D MOF not only efficiently absorbs and converts the microwave into heat for microwaveocaloric therapy (MCT) via enhanced hetero-interfacial polarization, but also generates excited electrons via surface state for microwave dynamic therapy (MDT). This biocompatible CNT-2D MOF exhibits highly effective broad-spectrum antimicrobial activity against seven pathogenic bacteria, including Gram-negative and Gram-positive pathogens, under 7 min MV irradiation. And this system is proven to efficiently eradicate Staphylococcus aureus infected rabbit tibia osteomyelitis. Significantly, MV-excited MCT and MDT of CNT-CuHHTP developed in this study makes a major step forward in antibiotic-free MV therapy in deep tissue bacterial infection diseases.

Automated summary

Microwave (MV)-trigged dynamic therapy using MV-responsive materials shows promise for treating deep infection diseases, including life-threatening osteomyelitis, that are not effectively treated by antibiotics. Surface states of materials play a key role in the generation of free charges and the MV dynamic effects. A new MV responsive system, consisting of a 2D metal-organic framework (2D MOF) on oxidized carbon nanotube (CNT), is developed, which exhibits highly effective antimicrobial activity and eradicates Staphylococcus aureus infected rabbit tibia osteomyelitis under MV irradiation. This study represents a major advancement in antibiotic-free MV therapy for deep tissue bacterial infection.