Carboxymethyl inulin functionalized gold nanoclusters within a chitosan matrix for biocompatible photothermal and...

Cancer therapy and bioimaging require advancements that improve selectivity, efficacy, and biocompatibility. Here, we developed chitosan-conjugated, carboxymethyl inulin-modified gold nanoclusters (CMI-GNCs) containing the near-infrared dye IR-820 and Proflavine hemisulfate (PfHS), aimed at enhancing cellular uptake, fluorescence for bioimaging, and photothermal therapy efficacy. Different nanoparticle formulations were synthesized and confirmed to be stable through dynamic light scattering (DLS) and Fourier-transform infrared spectroscopy (FTIR). Carboxymethyl inulin significantly boosted fluorescence, while chitosan improved cellular uptake, making CMI-GNCs suitable for imaging applications. In vitro tests on B16 cancer cells demonstrated that ChCGPI nanoparticles achieved temperatures above 45 °C under near-infrared irradiation, effectively inducing photothermal ablation of cancer cells. Clonogenic assays showed inhibited cancer cell regrowth, and apoptosis was confirmed through mitochondrial membrane potential and nuclear fragmentation assays. Anti-migration studies indicated that ChCGPI reduced cancer cell migration, suggesting anti-metastatic potential. In a separate study, we also assessed the anti-biofilm properties of CMI-GNCs against E. coli and found that CMI-GNC exhibited superior anti-biofilm effects compared to GNC alone Additionally, zebrafish embryo assays showed that CMI conjugation reduced the toxicity of GNCs, significantly improving biocompatibility. These findings highlight the promise of CMI-GNCs, particularly ChCGPI, as multifunctional platforms for bioimaging, targeted photothermal cancer therapy, and improved biocompatibility.