Artesunate Enhances the Cytotoxicity of 5-Aminolevulinic Acid-Based Sonodynamic Therapy against Mouse Mammary Tumor Cells In Vitro

Sonodynamic therapy (SDT) kills tumor cells through the synergistic effects of ultrasound (US) and a sonosensitizer agent. 5-Aminolevulinic acid (5-ALA) has been used as a sonodynamic sensitizer for cancer treatment. However, studies have shown that 5-ALA-based SDT has limited efficacy against malignant tumors. In this study, we examined whether artesunate (ART) could enhance the cytotoxicity of 5-ALA-based SDT against mouse mammary tumor (EMT-6) cells in vitro. In the ART, ART + US, ART + 5-ALA, and ART + 5-ALA + US groups, the cell survival rate correlated with ART concentration, and decreased with increasing concentrations of ART. Morphologically, many apoptotic and necrotic cells were observed in the ART + 5-ALA + US group. The percentage of reactive oxygen species-positive cells in the ART + 5-ALA + US group was also significantly higher than that in the 5-ALA group (p = 0.0228), and the cell death induced by ART + 5-ALA + US could be inhibited by the antioxidant N-acetylcysteine. These results show that ART offers great potential in enhancing the efficacy of 5-ALA-based SDT for the treatment of cancer. However, these results are only based on in vitro studies, and further in vivo studies are required

SiN AlGaN カイメン ノ デンシ コウゾウ ト ゲートリーク デンリュウ ノ カンケイ

AlGaN/GaN high electron mobility transistors (HEMTs) are recently applied to high-power RF devices. However, their relatively large gate leakage currents are preventing further improvement of Applications. The large gate leakage currents strongly depend on kinds of ap assivation film. In this study, in order to clarify the correlation between passivation films and gate leakage currents, we investigated the core-level electronic structure at the interface between an AlGaN barrier layer and a passivation film by using Hard X-ray Photoemission Spectroscopy (HAXPES) at BL16XU of SPring-8. At first we fabricated AlGaN/GaN HEMTs with the three kinds of SiN passivation films deposited by different N2 flow rates and measured their gate leakage currents. The gate leakage currents increased as lower N2 flow rate conditions. Then, we found the core level spectra by HAXPES shifted according to N2 flow rate conditions. These results indicate the gate leakage currents depend on the potential height at SiN/ AlGaN interface

Artesunate Enhances the Cytotoxicity of 5-Aminolevulinic Acid-Based Sonodynamic Therapy against Mouse Mammary Tumor Cells In Vitro

Sonodynamic therapy (SDT) kills tumor cells through the synergistic effects of ultrasound (US) and a sonosensitizer agent. 5-Aminolevulinic acid (5-ALA) has been used as a sonodynamic sensitizer for cancer treatment. However, studies have shown that 5-ALA-based SDT has limited efficacy against malignant tumors. In this study, we examined whether artesunate (ART) could enhance the cytotoxicity of 5-ALA-based SDT against mouse mammary tumor (EMT-6) cells in vitro. In the ART, ART + US, ART + 5-ALA, and ART + 5-ALA + US groups, the cell survival rate correlated with ART concentration, and decreased with increasing concentrations of ART. Morphologically, many apoptotic and necrotic cells were observed in the ART + 5-ALA + US group. The percentage of reactive oxygen species-positive cells in the ART + 5-ALA + US group was also significantly higher than that in the 5-ALA group (p = 0.0228), and the cell death induced by ART + 5-ALA + US could be inhibited by the antioxidant N-acetylcysteine. These results show that ART offers great potential in enhancing the efficacy of 5-ALA-based SDT for the treatment of cancer. However, these results are only based on in vitro studies, and further in vivo studies are required