Biophysical evaluation of treating adipose tissue-derived stem cells using non-thermal atmospheric pressure plasma.

Non-thermal atmospheric pressure plasma (NTAPP) is a partially ionized gas containing fast electrons and relatively slow ions. This study aims to investigate the influences of NTAPP on human adipose tissue-derived stem cells (ADSCs) and examine the feasibility of using optical spectroscopy as a non-destructive method for cell analysis. A plasma jet is used as the source of low-temperature plasma in which pure helium gas is ionized by a high voltage (8 kV) and frequency (6 kHz). ADSCs were exposed to the NTAPP for 30 s, 60 s, 90 s, and 120 s. The efficiency of the plasma treatment was investigated using flow cytometry and optical spectroscopy methods. This study compared surface markers of NTAPP treated and untreated ADSCs using CD90 and CD105 as positive markers. The result proved that NTAPP-exposed ADSCs maintain their stemming. Measuring ADSCS apoptosis by labeling Annexin V-Propidium Iodide showed that the plasma at short exposure time is relatively non-toxic. However, a longer exposure time can lead to apoptosis and necrosis. Moreover, Cell cycle analysis revealed that NTAPP accelerates the cell cycle in very low doses and can cause proliferation. In this experiment, flow cytometry measurements have been used to determine oxidative stress. The results showed that with increasing plasma dose, intracellular ROS levels reduced. This data also suggests that intracellular ROS are not responsible for the cells' viability. Furthermore, we used reflectance spectroscopy as a non-destructive method for evaluating treatment response and comparing this method with cell analysis techniques. The results indicate spectroscopy's efficiency as a method of cell analysis. This study suggests that NTAPP would be an efficient tool to improve ADSCs culture's efficiency in vitro; thus, we support the potential applications of NTAPP in the field of stem cell therapy and regenerative medicine.

Cold Atmospheric Plasma Versus Cisplatin Against Oral Squamous Cell Carcinoma: A Mitochondrial Targeting Study.

Plasma therapy and the study of the effects of cold atmospheric plasma (CAP) on tissues and living cells have been considered by scientific researchers in recent years. CAP is used in the treatment of cancer, but its anti-cancer mechanism has not been fully studied. Therefore, we studied the toxicity effect of CAP by using argon as feed gas and the synergistic effects of CAP with cisplatin on tumor cells and mitochondria isolated from tumor legions of the rat model of oral squamous cell carcinoma (OSCC). For this reason, we determined the possible toxic alterations of CAP on mitochondrial upstream events and activation of caspase-3 as the key major downstream event of apoptosis. Also, the effects of cisplatin (10 µM) as a positive control and its synergistic effects with CAP (IC50 concentration) were investigated. The results showed that CAP reduced mitochondrial dysfunction by reduction in succinate dehydrogenase (SDH) activity. Also, CAP in concentrations of 1200, 2400, and 4800 a.u. has been able to increase the level of reactive oxygen species (ROS), mitochondrial swelling, damage to the mitochondrial membrane, cytochrome c release, and activation of the final mediator of apoptosis (caspase-3) only in the OSCC group. CAP at 4800 a.u concentration had similar effects to cisplatin (10 µM). Synergistic effects between CAP (2400 a.u) and cisplatin (10 µM) have also been reported. Based on all results CAP showed positive and promising results on mitochondrial upstream parameters leading to activation of caspase-3, the final mediator of apoptosis only on OSCC cells and mitochondria without any significant effect on normal cells and mitochondria.

Role of Mitochondria and Lysosomes in the Selective Cytotoxicity of Cold Atmospheric Plasma on Retinoblastoma Cells.

Retinoblastoma (RB) is a common malignancy in childhood, with an incidence of 1 per 20,000 live births. Several approaches such as chemotherapy, laser, and radiotherapy have been used for the treatment of RB. However, the effectiveness of these methods is not sufficient and the mechanisms involved in the pathogenesis of the disease are not well understood. The disruption of the apoptotic process is considered as one of the mechanisms involved in the pathogenesis of RB. This study was designed to examine the in-vitro selective toxicity of cold atmospheric plasma (CAP) on RB cells' mitochondria and lysosomes. The results showed that CAP decreased cell viability and GSH content and also increased caspase-3 activity and lipid peroxidation (LPO) in cancerous ocular cells isolated from the rat model of RB compared to the normal rat ocular cells. Furthermore, results demonstrated that CAP significantly increased ROS generation, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, and cytochrome c release only in cancerous rat ocular mitochondria but not the normal rat ocular mitochondria. Furthermore, our results demonstrated that CAP significantly increased the lysosomal damage only in the cancer group. Altogether, the results of the study showed that CAP could selectively induce apoptosis on RB mitochondria. CAP may therefore be considered as a promising candidate for further in-vivo and clinical researches to reach a new anti- RB drug.

Synthesis of Ag/TiO2 nanocomposite via plasma liquid interactions: Improved performance as photoanode in dye-sensitized solar cell.

Ag/TiO2 nanocomposite was prepared by the atmospheric direct current plasma in aqueous solution to improve its performance in dye-sensitized solar cells (DSSCs) as the photoanode. The fabricated DSSC shows high power conversion efficiency over 6.5% and displays better long-term stability than that of referenced pure TiO2. The comparison of photoluminescence spectra of Ag/TiO2 and pure TiO2 showed that only the Ag containing samples had notable photocurrent under visible light, which was attributed to the highly dispersed Ag, according to the EDS and XRD measurements. The short-circuit current density (Jsc) and open-circuit voltage (Voc) reached 13.43 mA cm-2 and 0.72 V in Ag/TiO2, and 9.44 mA cm-2 and 0.68 V in pure TiO2, respectively. The performance improvement in Ag/TiO2 DSSC may occur due to the declined band-gap energy, retarded charge recombination and greater surface coverage of the sensitizing dye over Ag/TiO2 nanocomposite.