Abstract
This study reports, for the first time, development of tyrosine kinase inhibitor-loaded, thermosensitive liposomes (TKI/TSLs) and their efficacy for treatment of renal cell carcinoma when triggered by focused ultrasound (FUS). Uptake of these nanoparticles into renal cancer cells was visualized with confocal and fluorescent imaging of rhodamine B-loaded liposomes. The combination of TKI/TSLs and focused ultrasound was tested in an in vitro tumor model of renal cell carcinoma. According to MTT cytotoxic assay and flow cytometric analysis the combined treatment led to the least viability (23.4 ± 2.49%, p<0.001), significantly lower than that observed from treatment with FUS (97.6 ± 0.67%, n.s.) or TKI/TSL (71.0 ± 3.65%, p < 0.001) at 96 hours compared to control. The importance of this unique, synergistic combination was demonstrated in viability experiments with non-thermosensitive liposomes (TKI/NTSL+FUS: 58.8 ± 1.5% vs TKI/TSL+FUS: 36.2 ± 1.4%, p<0.001) and heated water immersion (TKI/TSL+WB43°: 59.3 ± 2.91% vs TKI/TSL+FUS: 36.4 ± 1.55%, p < 0.001). Our findings coupled with the existing use of focused ultrasound in clinical practice make the proposed combination of targeted chemotherapy, nanotechnology, and focused ultrasound a promising platform for enhanced drug delivery and cancer treatment.