A Magnetic Cloud Bomb for Effective Biofilm Eradication

Skin and soft tissue infection (SSTI) is an inflammatory condition caused by bacteria, and the eradication of biofilms is an important problem when treating such infections. Because of the low dispersibility and biofilm permeability of magnetic antibacterial materials, biofilm removal is difficult and infection persists. To solve these problems, inspired by conventional cloud bombs, a magnetic “nano-cloud bomb” by adjusting the synthesis ratio to alter the shape of an assembled zeolitic imidazolate framework (ZIF), namely ZIF-L-Fe, is synthesized simply and rapidly. ZIF-L-Fe has a flower-like clustered structure with sharp edges, which prevents the stacking of 2D ZIF nanoleaves, thereby enhancing the dispersion of Fe nanoparticles and increasing biofilm penetration under the action of magnetism. Additionally, ZIF-L-Fe retains the photothermal and catalytic properties of nanoparticles, which can kill methicillin-resistant Staphylococcus aureus (MRSA) at low temperature and efficiently catalyze hydrogen peroxide (H₂O₂). Because of its magnetic effect, ZIF-L-Fe can rapidly penetrate biofilm, thus forming craters and destroying the local biofilm structure. Accordingly, the proposed strategy of clustered ZIF-loaded delivery of Fe provides a novel concept that requires further development for clinical application to the treatment of biofilm infections.