A sequential treatment strategy by copper ion-doped nanofiber dressing for highly efficient biofilm combating and rapid wound healing.

• It is a great challenge to exhibit good antibiofilm activity of copper ions while minimize cell toxicity. • A metal-polyphenol-based catalytic system was designed to catalyze nitric oxide (NO) in combination with moderate photothermal/copper ions to systematically eradicate biofilms and promote wound healing process. • Subsequent treatments with moderate temperature (∼47℃) significantly enhanced bactericidal effect of low dose copper ions (∼1.2 μ g/mL) by deconstructing bacteria membrane. • The biofilm infection was successfully eradicated in only 250 min, significantly more effective than existing treatment methods. Copper ions are considered as a promising alternative to combat infected wound and accelerate wound healing. However, exhibiting good antibiofilm activity meanwhile minimizing cell toxicity remains a great challenge. To address this issue, we provide a sequential treatment strategy to combat biofilm infected wound with low copper ion (Cu2+) release (as low as 1.2 μg·mL−1). Polydopamine (PDA) adherent copper ion complex is constructed on thermoplastic polyurethane (TPU) to develop the Cu2+@PTPU nanofibers. With the application of Cu2+@PTPU wound dressing, nitric oxide (NO) gas is released by catalyzing endogenous donor, thereby rapidly eliminating more than 90 % biofilm biomass. Subsequent moderate photothermal treatment (∼47℃) significantly enhanced bactericidal effect by deconstructing bacteria membrane. As a result, the biofilm infection was eradicated in only ∼ 6h, significantly more effective than existing methods (∼24 h). Additionally, Cu2+@PTPU dressing not only exhibits excellent cell compatibility, but also promotes wound healing. In vivo study demonstrates that it reduces the level of inflammatory responses by 104 % and increases angiogenesis capacity by 115 %, compared with untreated group, thereby narrowing the wound site area by 72 % at day 14 after treatment. Overall, the Cu2+@PTPU dressing and sequential treatment strategy provide quick, safe, yet efficacious biofilm combating outcomes and facilitates rapid wound healing. [ABSTRACT FROM AUTHOR]