Enhancing gemcitabine delivery in mia-paca-2 cells using a combination of rapid short ultrasound pulse and microbubbles

Abstract

Pancreatic cancer remains one of the most lethal malignancies, with a 5-year survival rate below 10%, primarily due to late diagnosis, limited therapeutic options, and poor drug delivery. The tumor’s dense fibrotic stroma, abnormal vasculature, and elevated interstitial pressure significantly hinder the effective penetration of chemotherapeutic agents such as gemcitabine hydrochloride (dFdC HCl). Previous studies have shown that ultrasound-mediated microbubble therapy can enhance drug delivery in solid tumors, including pancreatic cancer. For example, ultrasound combined with microbubble treatment has been utilized to enhance paclitaxel uptake in breast tumor models and to enhance dFdC HCl uptake, leading to tumor regression in pancreatic cancer xenografts. However, many of these approaches involved prolonged ultrasound exposure or high acoustic pressures, often leading to microbubble destruction and tissue damage, thus limiting reproducibility and clinical translation. To address these limitations, our study evaluated the use of rapid short ultrasound pulse in combination with SonoVue microbubbles to enhance the delivery of dFdC HCl in MIA PaCa-2 pancreatic cancer cells. Cells were treated with increasing concentrations of dFdC HCl alone or in combination with ultrasound and microbubbles. Cell viability was assessed via MTT assay to find the IC50 value of dFdC HCl drug. The membrane permeability was assessed with fluorescence images to find optimal microbubble concentration and ultrasound intensity by evaluating the uptake of Ethidium Homodimer-1 (EtHD-1). An increase in EtHD-1 uptake was observed with 107 microbubbles at mid-intensity (275V) and also with high-intensity ultrasound pulses (400V) in the absence of microbubbles. dFdC HCl displayed a dose-dependent cytotoxic effect, which was significantly enhanced by ultrasound exposure. The inclusion of 10⁷ microbubble concentration further increased cytotoxicity, particularly at lower drug concentrations.