An antibacterial microneedle with chemodynamic therapy triggered by microwave thermal effect for diabetic infected...

Microwave-assisted therapy possesses a good prospect of clinical application in bacterial infections treatment owing to the excellent tissue penetration. However, the weak energy of microwave limits the catalytic performance of sensitizers to generate enough reactive oxygen species to kill bacteria. The Fe₃O₄@AIPH microneedle patch offers the potential to achieve effectively antibacterial and anti-inflammatory effects solely through microwave thermal effects, thereby accelerating wound healing in diabetic patients.

The objective of the study is to develop a microneedle patch utilizing microwave-responsive therapy to effectively eliminate bacterial infections and suppress inflammation, thereby accelerating the healing of diabetic infectious wounds.

Fe₃O₄@AIPH nanoparticles were constructed using a layer-by-layer self-assembly method and then loaded onto hyaluronic acid microneedle patches. The antibacterial capability of the microneedle patch was evaluated using S.aureus/E.coli, and the antibacterial mechanism was analyzed using RNA sequencing technology and molecular dynamics simulation. The biocompatibility and anti-inflammatory capability of the microneedle patch were evaluated using fibroblasts/macrophages. Finally, an animal model was constructed to evaluate the ability of the microneedle patch to promote the healing of diabetic infected wounds.

The microneedle inhibited the amino acid biosynthesis process and GSH transferase homolog activity in bacteria, achieving antibacterial rates of 98.72 % (S. aureus) and 99.99 % (E. coli) at mild temperature within 10 min irradiation, respectively. Additionally, microneedle patches can suppress inflammatory responses near diabetic infection wounds.

Fe₃O₄@AIPH microneedle patch exhibit excellent antibacterial and anti-inflammatory properties under microwave irradiation, effectively accelerating the healing process of diabetic infected wounds. Additionally, both ferrite and microwave therapy devices have received FDA approval for medical purposes, offering potential for the clinical application of microwave-responsive Fe₃O₄@AIPH microneedle patches. Long-term microwave-assisted therapy may carry the potential risk of excessive skin temperatures, capable of alleviation through improvement in material microwave absorption efficiency or adoption of a segmented treatment strategy.