Nanocarrier Incorporating Fucoidan/Chitosan for Co-Encapsulation of TMB, Glucose Oxidase and Prussian Blue: Applications in Chemotherapy, Photothermal Therapy and Glucose Starvation Treatment

Fucoidan, a naturally occurring sulfated polysaccharide derived from marine brown algae, has been explored as a promising therapeutic nanoparticle for cancer treatment. Effective strategies such as chemotherapy, photothermal therapy, and glucose starvation can create a conducive environment for successful cancer eradication. Harnessing the potential of functionalized fucoidan nanoparticles in combination with chitosan, acting as a nanocarrier, presents an opportunity for biological activation, particularly in abnormally acidic extracellular environments. In this study, we developed a fucoidan (Fu)-chitosan (CS) nanocarrier through a self-assembly technique and encapsulated it with 3,3′,5,5′-tetramethylbenzidine (TMB), prussian blue (P), and glucose oxidase (GOx) (Fu/CS@TPGOx). The synthetic multi-stimuli-responsive Fu/CS@TPGOx nanoparticles were characterized using dynamic light scattering (DLS), zeta potential, UV absorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. DLS analysis indicated an average particle size of 440 nm, consistent with the spherical morphological structures observed in TEM results. Moreover, the positive zeta potential of 22.9 mV affirmed the stability of the synthesized particles.<br/>The catalytic efficacy of Fu/CS@TPGOx nanoparticles is confirmed through UV absorption studies, revealing specific absorbance spectra at 652 nm. Additionally, a prominent peak at 810 nm signifies substantial absorption in the near-infrared (NIR) range, rendering it particularly suitable for photothermal treatment. The photothermal performance of the newly developed Fu/CS@TPGOx nanoparticles was assessed by subjecting them to an 808 nm NIR laser at concentrations of 7.7, 3.85, and 0.77 μg/mL, with a power density of 0.75 W/cm². Results indicated a proportional increase in temperature with nanoparticle concentration. Notably, at 7.7 μg/mL Fu/CS@TPGOx nanoparticles, the temperature reached 55.2 °C, providing an optimal condition for the targeted destruction of breast cancer cells (MDA-MB-231) following a continuous 10 minute exposure to an 808 nm laser with a power density of 0.75 W/cm².<br/>The WST-1 assay, a live-dead cell staining method, validates the anticancer properties of Fu/CS@TPGOx in MDA-MB-231 cancer cells. Fu/CS@TPGOx exhibited 40% cytotoxicity in MDA-MB-231 cells under chemodynamic treatment and glucose starvation conditions at a dose of 0.77 μg/mL. Furthermore, the cytotoxicity increased to 55% during photothermal effects with chemodynamic treatment and glucose starvation by exposing Fu/CS@TPGOx to an 808 nm laser at 0.75 W/cm² for 10 minutes. The live-dead cell staining experiment yielded similar results, highlighting Fu/CS@TPGOx's significant potential as a cancer therapeutic. Moreover, DCFH-DA analysis confirms that under photothermal conditions with chemodynamic therapy and glucose starvation, the generation of reactive oxygen species was higher in the 0.77 μg/mL Fu/CS@TPGOx treatment. This suggests that Fu/CS@TPGOx played a crucial role in activating OH^- in cancer cells.<br/>The flow cytometry study provides evidence supporting the cytotoxic effects of 0.77 μg/mL Fu/CS@TPGox under laser conditions, yielding the highest rate of apoptosis (84.5%) compared to glucose starvation and chemodynamic treatment (60%). The utilization of three anti-cancer strategies—chemotherapy, photothermal treatment, and glucose starvation—is evident in the findings, showcasing Fu/CS@TPGox's substantial anti-cancer impact at low concentrations. This research holds the potential to contribute to the development of more effective anticancer therapies for cancer treatment. A comprehensive investigation of these novel materials will be conducted to assess their in vivo efficacy and toxicity in comparison to other anti-cancer drugs in the future.<br/><br/><b>Keywords: </b>Fucoidan, Chitosan, Photothermal therapy, Chemodynamic therapy, Glucose starvation