Engineering stimuli-responsive carboxymethyl starch /agarose-based nanocarriers incorporating carbon nanotubes for targeted 5-fluorouracil delivery

This study introduces a pH-sensitive nanoformulation designed to enhance the targeted delivery and controlled release of 5-fluorouracil (5-FU) for cancer treatment. By incorporating carboxymethyl starch (CMS), agarose (Aga), and carbon nanotubes (CNTs), the formulation achieved a high drug loading capacity of 46.25% and an encapsulation efficiency of 88.50%, demonstrating pronounced efficacy within acidic tumor microenvironments. The successful integration of components was confirmed, and the morphological study revealed a uniform spherical morphology, which is advantageous for biomedical applications and extended systemic circulation. The nanoformulation exhibited particle sizes of approximately 44.7 nm and 29.5 nm, ensuring consistent dosing, reducing variability in drug release profiles, and enhancing intracellular delivery potential. Zeta potential measurements indicated robust colloidal stability with a value of −41 mV. Furthermore, in vitro drug release studies revealed a sustained and pH-responsive release profile, with significantly enhanced drug release under acidic conditions (pH 5.4), mimicking the tumor microenvironment. In vitro cytotoxicity studies demonstrated that the CMS/Aga/CNTs@5-FU formulation significantly reduced the viability of A549 lung cancer cells by over 40% while exhibiting minimal toxicity toward normal L929 fibroblast cells.