oxaliplatin-loaded chitosan nanoparticles decorated with cetuximab single-chain variable fragment for human colorectal cancer treatment

Objective: colorectal cancer (crc) is the second leading cause of cancer-related deaths worldwide. engineeredbiomolecules can be used as a targeted tool to deliver drugs directly to tumors that reduce the adverse effects of conventionaltreatments. we aimed to prepare non-targeted oxaliplatin-loaded chitosan nanoparticles (oxpt-cs nps) and targetedoxpt-cs nps decorated with cetuximab single-chain variable fragment (scfv) to send both nps to epidermal growth factorreceptor (egfr) overexpressing hct 116 cells, a human colorectal carcinoma cell line, for comparing their cytotoxicity.materials and methods: in this experimental study, oxpt-cs nps were synthesized using a fluid system. encapsulationefficiency percentage (ee%) and oxaliplatin release rate were evaluated. western blot and cell-based elisa confirmed scfvproduction and its binding ability to egfr, respectively. the fourier transform infrared spectroscopy (ftir) determinedthe conjugation of scfv to oxpt-cs nps. the nps were characterized, and their toxicity against the hct 116 cells wasevaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (mtt) and flow cytometry assays.results: the ee% of oxpt-cs nps was 93%, and the average diameters were 75.85 ± 8.81 nm and 92.48 ± 9.51before and after scfv conjugation, respectively. the scfv was purified via affinity chromatography. the western blotmethod and cell-based elisa revealed successful purification of scfv and its attachment to egfr on hct 116 cells.the ftir analysis determined the interactions between the scfv and oxpt-cs nps. according to mtt and flowcytometry results, the targeted delivery system significantly reduced hct 116 cancer cell viability and increasedapoptosis induction up to 99.8%.conclusion: the scfv-oxpt-cs nps demonstrated an increased cytotoxic function due to the presence of scfv in itsformulation. this delivery system offers a promising method for delivering chemotherapy drugs to cancer cells. moreresearch is needed on the best strategies for improving treatment efficacy by targeting cancer cells.