Photothermal-responsive fiber dressing with enhanced antibacterial activity and cell manipulation towards promoting wound-healing

For chronic persistent skin injuries, functional wound dressings with improved antibacterial action and cell control are extremely appealing. In this study, we design and fabricate a composite fiber dressing with near-infrared (NIR) laser-induced hyperthermia and transformable topographies that can protect the wound from bacterial infection while also encouraging cell recruitment and tissue regeneration. Polycaprolactone/gelatin (PCL/Gel) with melting point close to photothermal temperature were electrospun as the supporting matrix. The zeolitic imidazolate framework-8 (ZIF-8)-derived nanocarbon was synthesized as NIR laser-triggered nanoagent and then electrospun within oriented PCL/Gel fibers to enable the inorganic/polymer composite fiber dressing with photo-to-thermal conversion effect and drug loading capability. The composite fiber dressing exhibits excellent photothermal performance and stage-specific transformable topographies (photothermal-triggered melting behavior of oriented PCL/Gel fibers) after multiple laser irradiations, which can generate local massive heat and abundant drug release for synergistic sterilization, as well as direct cell migration and adhesion/spreading to promote tissue regeneration. Furthermore, in vivo testing demonstrates that the photothermal-responsive fiber dressing accelerates wound closure process by synergistically improving antibacterial and cell manipulation. Overall, this composite fiber dressing offers a promising integrated wound healing strategy.