Abstract
Background: Gastric cancer remains one of the leading causes of cancer-related deaths worldwide, and the development of effective, targeted drug delivery systems is crucial to improve therapeutic outcomes. Graphene oxide (GO)-based nanocarriers have shown promise for controlled drug release, yet their biological evaluation remains limited. Methods: We synthesized a composite nanoparticle system by electrostatic self-assembly of chitosan (CS) onto graphene oxide (GO), followed by doxorubicin (DOX) loading. The resulting GO–CS–DOX nanoparticles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, and pHresponsive release profiles. Preliminary biological performance was evaluated in gastric cancer cells (AGS), including dose–response cytotoxicity and fluorescence-based uptake studies. Results: GO–CS– DOX nanoparticles showed a clear pH-dependent DOX release behavior, with accelerated release under mildly acidic conditions. DLS and zeta potential measurements confirmed successful drug loading and changes in surface charge. In vitro, GO–CS–DOX demonstrated comparable or slightly enhanced cytotoxicity relative to free DOX at specific concentrations. Cellular uptake of DOX was observed under acidic conditions, consistent with lysosomal trafficking. However, only preliminary in vitro data were collected and no mechanistic apoptosis studies were performed. Conclusion: This study presents the design and initial evaluation of a pH-responsive GO–CS–DOX nanocarrier. While the in vitro results indicate potential for controlled drug release and tumor-targeted delivery, the biological findings are still limited and should be interpreted as preliminary. Further in-depth studies, including apoptosis assays and in vivo validation, are necessary to fully establish therapeutic efficacy.
Keywords: Gastric cancer; pH-responsive; graphene oxide; chitosan; doxorubicin; controlled release; nanocarrier