Synthesis of Nanocarrier Based on Chitosan/Agarose Biopolymers Containing Carbon Quantum Dot Doped Titanium Dioxide for Targeted Delivery of 5-Fluorouracil for Brain Cancer Treatment

5-Fluorouracil (5-FU) is a clinically established anticancer drug effective in treating various solid tumors, including colorectal, breast, and pancreatic cancers. However, its therapeutic efficacy is often hindered by rapid metabolism and the development of drug resistance. This study investigates a nanocomposite comprising chitosan (CS), agarose (Aga), carbon quantum dots (CQDs), and titanium dioxide (TiO2_CQDs) as a potential nanocarrier (NC) to enhance 5-FU delivery. A CS/Aga hydrogel was synthesized through physical cross-linking to improve biocompatibility. Subsequently, the drug-loaded nanocomposite (CS/Aga/TiO2_CQDs@5-FU) was prepared using a W/O/W double emulsion process. A comprehensive characterization of the NC and 5-FU incorporation was conducted. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were employed to evaluate the crystalline properties of the nanoparticles (NPs) and confirm 5-FU integration. Dynamic light scattering (DLS) and zeta potential measurements assessed the stability and particle size distribution of the drug-loaded nanocomposites, confirming the formation of stable NPs. Field emission scanning electron microscopy (FE-SEM) verified the uniform dispersion of NPs, characterized by smooth and nearly spherical structures. Drug release kinetics were evaluated under controlled conditions. The encapsulation efficiency (EE) and loading efficiency (LE) were determined to be 86% and 47.25%, respectively, indicating the nanocomposite's high drug-carrying capacity. An MTT assay on U-87 MG and L929 cell lines demonstrated the biocompatibility of the fabricated NC. Notably, the drug-loaded nanocomposite exhibited lower cytotoxicity compared to pure 5-FU. These findings suggest that the nanocomposite holds promise as a drug delivery system, particularly for overcoming challenges associated with brain cancer treatment.