Role of HSP70 inhibition and chlorin E6 loaded microbubbles in sonodynamic therapy for stomach cancer cells

Objective: The aim of our research is to investigate the role of HSP 70 inhibition and chlorine e6 loaded microbubbles in the application of sonodynamic therapy to gastric cancer cells. Materials and Methods: After analyzing microbubble sizes using different methods, cells were treated with pifithrin-μ for 48 hours to inhibit heat shock protein 70 in MKN28 gastric cancer cells. Post pifithrin-μ treatment, cells were exposed to chlorine e6-loaded microbubbles for 12 hours, collapsed using ultrasound (1MHz, 3W/cm2, 20% pulse, 30sec). Cytotoxicity and apoptosis variations between groups were assessed through molecular techniques. Results: Microbubbles, sized 1-5 µm, showed even distribution. Ultrasound disruption of chlorin e6-loaded microbubbles led to significant cavitation increase. Spectroscopy revealed no aggregation in chlorin e6 trisodium solution, awaiting confirmation. Cytotoxicity tests favored 5µM pifithrin-μ and chlorin e6 doses. Pulsed ultrasound (1MHz, 3W/cm², 20% duty, 30s) led to significant cytotoxicity and apoptosis with disrupted chlorin e6 microbubbles, synergizing with HSP inhibition. Conclusion: As a result, it was observed that the increased cell death and apoptosis data observed in the combined groups were statistically significantly higher than the sum of the effect seen in the ultrasound, pifithrin-μ and chlorine e6 loaded microbubble groups alone.