Fabrication of Cu(II)-porphyrin complex-conjugated chitosan nanoparticles for catalytic, oxidation, and biomedical applications.

The design of multifunctional nanomaterials that integrate catalytic, antimicrobial, antioxidant, and anticancer properties is becoming increasingly important for biomedical and environmental applications. In this study, meso-tetrakis(4-pyridyl)porphyrin (TPyP) and its copper(II) complex (Cu(II)TPyP) were successfully synthesized and conjugated with chitosan nanoparticles (CNs) to obtain Cu(II)TPyP@CNs. Comprehensive characterization using FTIR, SEM, TEM, DLS, and TGA confirmed the successful conjugation, nanoscale morphology, and high stability of the hybrid material. Catalytic studies revealed that Cu(II)TPyP@CNs efficiently catalyze the oxidation of 2-aminophenol to 2-aminophenoxazine-3-one, mimicking phenoxazinone synthase, with excellent recyclability over multiple cycles. Biological assessments demonstrated that Cu(II)TPyP@CNs exhibit enhanced antimicrobial activity against Escherichia coli, Bacillus subtilis, and Candida albicans compared to Cu(II)TPyP alone. Antioxidant evaluation using DPPH• and ABTS+ assays confirmed strong radical-scavenging activity, highlighting their potential in mitigating oxidative stress. In vitro anticancer assays showed that Cu(II)TPyP@CNs significantly inhibited the proliferation of HCT-116, HepG2, and MCF-7 cancer cells with minimal cytotoxicity toward normal WI-38 fibroblasts, contrasting with the nonspecific toxicity of doxorubicin. Molecular docking further validated the selective inhibition of Akt/ERK1/2 pathways, supporting the compounds' anticancer potential. Overall, the multifunctional profile of Cu(II)TPyP@CNs demonstrates its promise as a next-generation nanomaterial-based therapeutic, bridging catalysis, antimicrobial defense, antioxidant protection, and targeted cancer therapy.