NIR-responsive engineered colloidal polyaniline/ZnO/UiO-66-NH₂ nanoplatform: A multifunctional photothermal agent for precision therapy in breast cancer

A colloidal polyaniline/ZnO/UiO-66-NH₂ (PANI/ZnO/UiO-66-NH₂) nano-platform was constructed in two steps. The nano-platform exhibited strong optical absorption in the near-infrared (NIR) region, enabling efficient conversion of optical energy into thermal energy under 808-nm laser irradiation, thereby facilitating tumor cell ablation. Characterization was performed using FT-IR, EDX, XRD, FESEM, UV-Vis, and TG. Biological activities, including antioxidant and antibacterial properties, as well as cytotoxicity, were evaluated. The nanocomposite exhibited high photothermal efficiency, reaching 60 °C in 10 min under an 808 nm NIR laser (0.6 W/cm², 1.5 mg/mL), confirming its potential for hyperthermia-based cancer therapy. At 0.15 mg/mL, the temperature rose to 49 °C, demonstrating its concentration and laser power dependence for effective photothermal therapy (PTT). In vitro cytotoxicity analysis on MCF-7 breast cancer cells showed a significant reduction in cell viability under NIR laser irradiation. The MTT assay confirmed that combining the nanocomposite with laser treatment led to a substantial decrease in cancer cell survival, highlighting its potential as a photothermal agent. Additionally, the antioxidant activity of the colloidal PANI/ZnO/UiO-66-NH₂ nanocomposite was found to be 90.64 %, comparable to the highest observed efficiency of UiO-66-NH₂ (94.20 %), and potent antibacterial effects against Escherichia coli (E. coli) , Bacillus subtilis (B. subtilis) , Salmonella enteritidis (S. enteritidis) , and Staphylococcus aureus (S. aureus) . Inhibition zone diameters for S. enteritidis and E. coli were 15 ± 0.3 mm and 13 ± 0.1 mm, respectively, underscoring dual applicability in PTT and antibacterial therapy. The MTT assay revealed that colloidal PANI/ZnO/UiO-66-NH₂ reduced the viability of MCF-7 cells to 40 % after 48 h of exposure. The IC₅₀ value of the colloidal PANI/ZnO/UiO-66-NH₂ for inhibiting the growth of MCF-7 cells increased from 17.13 µg/mL after 24 h to 32.3 µg/mL after 48 h. Additionally, hemolysis testing demonstrated that the nano-platform exhibited a hemolysis rate of 5 % at a concentration of 100 μg/mL. These results highlight the nanocomposite’s broad biomedical potential.