Polydopamine Nanoplatform for Synergistic Photothermal and Antibiotic Treatment of Catheter-Associated Urinary Tract Infection

Catheter-associated urinary tract infection (CAUTI), resulting from the formation of uropathogenic Escherichia coli (UPEC) biofilm, is one of the most common hospital infections, which increases patient morbidity. The biofilm’s extracellular polymeric substances form a physical barrier restraining deeper penetration of antibiotics, resulting in the failure of treatments. Photothermal therapy (PTT), which is capable of deactivating the active substance through the photothermal effect, can disrupt the extracellular polymer substances of the biofilm and improve the bactericidal effect of antibiotics. However, the high local temperature related to PTT inevitably causes thermal damage to the surrounding healthy tissue. Herein, a bioinspired polydopamine nanoplatform for the low-temperature photothermal and antibiotic combined treatment of CAUTI is developed. The nanoplatform was modified with the target ligand, Man, making photothermal energy of the nanoplatform predominantly transferred to the proximate bacterial and thus eradicating the biofilm at a lower temperature. Notably, 4-carboxy-3-fluorophenylboronic acid was introduced into polydopamine which endows the material with pH 5.5 stimuli-responsive drug release. The release amount can be up to ∼ 100%. Moreover, it can avoid biofilm reformation by inhibiting quorum sensing, greatly reducing the potential for recurrent infections. Overall, this bioinspired polydopamine nanoplatform provides a viable strategy in eradicating the biofilm formed by UPEC.