Fixed orthodontic appliances facilitate bacterial accumulation on brackets and wires, increasing the risk of enamel demineralization and periodontal inflammation. To address this challenge, near-infrared (NIR) responsive nanofibrous mats were developed for on-demand antibacterial disinfection of orthodontic brackets by incorporating cuttlefish ink-derived melanin nanoparticles (MNPs) into a poly(vinyl alcohol)/poly(ethylene oxide) (PVA/PEO) matrix. The incorporation of MNPs improved physicochemical properties, including enhanced thermal stability (∼77 °C increase in decomposition temperature), increased swelling capacity (∼2-fold compared with melanin-free fibers), and improved wettability. After thermal cross-linking, the fibrous network remained structurally stable in aqueous conditions with morphology preserved for up to 1 month and low melanin loss. Strong antioxidant performance was observed, reaching ∼60% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging after 10 h. In vitro evaluation using L929 fibroblasts confirmed good cytocompatibility, supporting adhesion, viability, and proliferation. Under NIR irradiation at 808 nm (1.5 W/cm2, 10 min), efficient photothermal heating was achieved under wet conditions (∼55–60 °C) with stable performance across repeated cycles. Antibacterial efficacy was demonstrated, reducing Escherichia coli survival to 0.55% and disinfecting bacteria-contaminated bracket surfaces, while only minor inhibition of Lactobacillus acidophilus was detected. Overall, a biocompatible, marine-derived, and sustainable nanofibrous mat are presented for on-demand orthodontic disinfection.
Bartolewska et al. (2026) studied this question.