Ultrasound-mediated intracellular delivery of fluorescent dyes and DNA into microalgal cells

Ultrasonic stimulation of the brain to enhance the release of dopamine - A potential novel treatment for Parkinson's disease

Parkinson's disease (PD) is characterized by the decrease of dopamine (DA) production and release in the substantia nigra and striatum regions of the brain. Transcranial ultrasound has been exploited recently for neuromodulation of the brain in a number of fields. We have stimulated DA release in PC12 cells using low-intensity continuous ultrasound (0.1 W/cm² - 0.3 W/cm², 1 MHz), 12 h after exposure at 0.2 W/cm², 40 s, the amount of DA content eventually increased 78.5% (p = 0.004). After 10-day ultrasonic treatment (0.3 W/cm², 5 min/d), the DA content in the striatum of PD mice model restored to 81.07% of the control (vs 43.42% in the untreated PD mice model). In addition to this the locomotion activity was restored to the normal level after treatment. We suggest that the low intensity ultrasound-induced DA release can be attributed to a combination of neuron regeneration and improved membrane permeability produced by the mechanical force of ultrasound. Our study indicates that the application of transcranial ultrasound applied below FDA limits, could provide a candidate for relatively safe and noninvasive PD therapy through an amplification of DA levels and the stimulation of dopaminergic neuron regeneration without contrast agents.

Ultrasound-assisted coagulation for Microcystis aeruginosa removal using Fe3O4-loaded carbon nanotubes

Harmful cyanobacterial blooms are increasing environmental issues and require novel removal technology since the required doses of algaecides may cause further environmental pollution or treatment facility damage. Herein, we firstly introduce the combination of ultrasound and Fe₃O₄/CNTs as an alternative strategy to enhance coagulation for the removal of Microcystis aeruginosa cells in water. It remarkably enhanced cyanobacterial cell removal and microcystins control, compared with sonication alone (40 kHz ultrasonic bath, 4.2 mJ mL⁻¹). 94.4% cyanobacterial cells were removed using 20 second sonication with 20 mg L⁻¹ Fe₃O₄/CNTs, Al₂(SO₄)₃ coagulation (20 μM). Both sonication time and catalyst dose significantly influenced the cyanobacterial removal. Ultrasound with Fe₃O₄/CNTs only induced a slight increase of cell permeability, which may contribute to the effective control of DOC and microcystins' release in water. The enhanced settlement of the cyanobacterial cells may result from the moderate oxidation on the cell surface. This study suggested a novel ultrasound-Fe₃O₄/CNT process to promote cyanobacteria removal with efficient DOC and microcystin release control, which is a green and safe technology for drinking water treatment.

The combination of sonication and Fe₃O₄/CNTs were applied on Microcystis aeruginosa removal for the first time.

Sonochemical synthesis of Fe3O4/carbon nanotubes using low frequency ultrasonic devices and their performance for heterogeneous sono-persulfate process on inactivation of Microcystis aeruginosa

Iron oxide nanoparticles decorated on multi-wall nanotube (MWCNTs) were successfully fabricated through a facile and rapid sonochemical method without any pre-treatment on MWCNTs. Fe₃O₄/MWCNTs-20 showed a uniform and fine distribution of nanoparticles in the MWCNTs. The obtained Fe₃O₄/MWCNTs were analysed using TEM and XPS. Notably, Fe₃O₄/MWCNTs were used for persulfate activation on cyanobacterial cell removal. With 20 mg/L persulfate, Fe₃O₄/MWCNTs showed an efficient catalytic performance after 1 h treatment. In the Fe₃O₄/MWCNTs hybrid catalyst, Fe₃O₄ helps to produce sulfate radicals and hydroxyl radicals whereas the size of the Fe₃O₄ clusters could affect the electron transfer for radical generation. Moreover, using high frequency low intensity ultrasound, the combination of persulfate and Fe₃O₄/MWCNTs-20 reduced the remaining cell number to 9.4% within 30 min treatment. In conclusion, our work demonstrated that low frequency ultrasonic devices are capable of fabricating Fe₃O₄/MWCNTs via a simple and time-saving route, and the obtained catalysts showed superior catalytic performance on persulfate for harmful cyanobacteria control.

Sono-Fenton hybrid process on the inactivation of Microcystis aeruginosa: Extracellular and intracellular oxidation

For the first time, the inactivation of Microcystis aeruginosa using sono-Fenton process at low frequency high intensity (20 kHz, 0.42 W/mL) and high frequency low intensity (800 kHz, 0.07 W/mL) was investigated, respectively. 20 kHz sono-Fenton treatment successfully reduced cyanobacterial cell number from 4.19 × 10⁶ cells/mL to 0.45 × 10⁶ cells/mL within 5 min treatment. Alternatively, efficient performance of 800 kHz sono-Fenton process was observed to decrease Microcystis cell number to 2.33 × 10⁶ cells/mL after 5 min inactivation, with lower energy cost. It was found that powerful 20 kHz sonication induced pore formation on the cell wall, leading to extracellular damage, while 800 kHz irradiation with low intensity triggered intracellular uptake of chemicals, suggesting endocytosis effects. Furthermore, sono-Fenton Processes were found to be affected by the concentrations of Fenton's reagent, and pre-sonication time. Although solo Fenton treatment released microcystins in water, the degradation of microcystin-LR were achieved using 20 and 800 kHz sono-Fenton processes, respectively. The results of this work showed that severe extracellular oxidation is the vital inactivation mechanism of 20 kHz sono-Fenton process, while the internal oxidation caused by intracellularly delivered Fenton reagents is suggested to be the main cause of 800 kHz sono-Fenton inactivation, leading to much lower energy cost. This work provides alternative methods to control harmful cyanobacteria in water towards effective treatment.

5-Fluorouracil ethosomes - skin deposition and melanoma permeation synergism with microwave

This study focuses on the use of ethosome and microwave technologies to facilitate skin penetration and/or deposition of 5-fluorouracil in vitro and in vivo. Low ethanol ethosomes were designed and processed by mechanical dispersion technique and had their size, zeta potential, morphology, drug content and encapsulation efficiency characterized. The skin was pre-treated with microwave at 2450 MHz for 2.5 min with ethosomes applied topically and subjected to in vitro and in vivo skin drug permeation as well as retention evaluation. The drug and/or ethosomes cytotoxicity, uptake and intracellular trafficking by SKMEL-28 melanoma cell culture were evaluated. Pre-treatment of skin by microwave promoted significant drug deposition in skin from ethosomes in vitro while keeping the level of drug permeation unaffected. Similar observations were obtained in vivo with reduced drug permeation into blood. Combination ethosome and microwave technologies enhanced intracellular localization of ethosomes through fluidization of cell membrane lipidic components as well as facilitating endocytosis by means of clathrin, macropinocytosis and in particularly lipid rafts pathways. The synergistic use of microwave and ethosomes opens a new horizon for skin malignant melanoma treatment.