Environmental innovation: polyaniline-cuttlebone nanocomposite as a potent antimicrobial agent and a synergistic barrier against doxorubicin-induced toxicity.

This work emphasizes the importance of utilizing cuttlebone waste as a sustainable solution for waste management and the development of antimicrobial materials by incorporating it as a supporting phase for polyaniline (PANI) to form a nanocomposite. The three prepared materials were fully characterized using various techniques, including FTIR, XRD, SEM, EDX for elemental analysis, Brunauer-Emmett-Teller (BET) surface area measurements, particle size distribution analysis, and zeta potential measurements. The study focuses on the development of novel molecules with potential antibacterial and antifungal activity against clinical pathogens responsible for infectious diseases. The antibacterial and antifungal activities of the polyaniline/cuttlebone (PANI/CB) composite were evaluated using methods such as minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and disk diffusion for bacterial samples, as well as MIC, minimum fungicidal concentration (MFC), antifungal percentage, and disk diffusion for fungal samples. Notably, the PANI/CB composite exhibited a distinct crystallite size and characteristic XRD pattern, along with a significant BET surface area, demonstrating strong antimicrobial properties. Cuttlebone not only serves as a bioactive agent but also acts as a sustainable support to enhance the properties of polyaniline, forming a nanocomposite with a low MIC range (8-66 μg mL) and effective action against Gram-positive bacteria such as , although it showed less susceptibility against Gram-negative bacteria like . The MTT assay results demonstrated that while PANI and CB alone exhibited minimal cytotoxicity on Huh7 cells, the combination of doxorubicin (DOX) with PANI/CB significantly enhanced the cytotoxic effect, suggesting a synergistic interaction that could improve the therapeutic efficacy of DOX. Additionally, the effectiveness of the polyaniline/cuttlebone composite in protecting against DOX-induced hepatic and renal damage in rats was evaluated. Tissue damage was assessed using serum markers such as alanine transaminase (ALT), aspartate transaminase (AST), urea, and creatinine. The results demonstrated a decrease in oxidative damage and significant improvements in liver and kidney function markers in the polyaniline/cuttlebone-treated groups compared to those treated with individual components. Specifically, ALT levels decreased from 48 ± 2.8 IU L to 21 ± 0.4 IU L, AST from 195 ± 0.7 IU L to 13 ± 1.08 IU L, urea from 86 ± 1.4 mg dL to 39 ± 0.7 mg dL, and creatinine from 1.05 ± 0.03 mg dL to 0.53 ± 0.01 mg dL. These findings highlight the potential of utilizing cuttlebone waste as a sustainable material in antimicrobial applications, offering an eco-friendly solution for waste management while contributing to the development of potent antimicrobial nanocomposites.