Optimization of critical parameters for coating of polymeric nanoparticles with plasma membrane vesicles by sonication

Top-down functionalization of nanoparticles with cellular membranes imparts nanoparticles with enhanced bio-interfacing capabilities. Initial methods for membrane coating involved physical co-extrusion of nanoparticles and membrane vesicles through a porous membrane; however, recent works employ sonication as the disruptive force to reform membranes around the surface of nanoparticles. Although sonication is widely used, there remains a paucity of information on the effects of sonication variables on coating efficiency, leading to inconsistent membrane coating across studies. In this work, we present a systematic analysis of the sonication parameters that influence the membrane coating. The results showed that sonication amplitude, time, temperature, membrane ratio, sample volume, and density need to be considered in order to optimize membrane coating of polymeric nanoparticles.

Process Efficiency and Energy Consumption during the Ultrasound-Assisted Extraction of Bioactive Substances from Hawthorn Berries

This study investigated the impact of sonication parameters on the efficiency of the extraction of bioactive substances from hawthorn berries. The ultrasonic treatment was performed in two modes: continuous and pulse. In the pulse mode, the samples were sonicated with the following processor settings: 1 s on-2 s off. The effective ultrasonic processor times were 5, 10, and 15 min, and the total extraction times were 15 min, 30 min, and 45 min. The content of total polyphenols and total anthocyanins was determined by a spectrophotometric method. We show that the operating mode of the processor affects extraction efficiency, energy consumption and unit energy inputs. Extraction supported by a pulsating ultrasonic field allowed saving from 20% to 51% of energy with a simultaneous higher efficiency of the process. In addition, we show that the unit energy consumption in the pulsed mode was about 40% to 68% lower than the energy consumption in the case of continuous operation.

Evaluation of sonication on stability-indicating properties of optimized pilocarpine hydrochloride-loaded niosomes in ocular drug delivery

Niosomes are increasingly explored for enhancing drug penetration and retention in ocular tissues for both posterior and anterior eye delivery. They have been employed in encapsulating both hydrophilic and hydrophobic drugs, but their use is still plagued with challenges of stability and poor entrapment efficiency particularly with hydrophilic drugs. As a result, focus is on understanding the parameters that affect their stability and their optimization for improved results. Pilocarpine hydrochloride (HCl), a hydrophilic drug is used in the management of intraocular pressure in glaucoma. We aimed at optimizing pilocarpine HCl niosomes and evaluating the effect of sonication on its stability-indicating properties such as particle size, polydispersity index (PDI), zeta potential and entrapment efficiency. Pilocarpine niosomes were prepared by ether injection method. Composition concentrations were varied and the effects of these variations on niosomal properties were evaluated. The effects of sonication on niosomes were determined by sonicating optimized drug-loaded formulations for 30 min and 60 min. Tween 60 was confirmed to be more suitable over Span 60 for encapsulating hydrophilic drugs, resulting in the highest entrapment efficiency (EE) and better polydispersity and particle size indices. Optimum sonication duration as a process variable was determined to be 30 min which increased EE from 24.5% to 42% and zeta potential from (−)14.39 ± 8.55 mV to (−)18.92 ± 7.53 mV. In addition to selecting the appropriate surfactants and varying product composition concentrations, optimizing sonication parameters can be used to fine-tune niosomal properties to those most desirable for extended eye retainment and maintenance of long term stability.

Can ultrasonic parameters affect the impact and water barrier properties of nano-clay filled glass fiber/polyester composites?

Good dispersion of the nanoparticles into the polymer is considered a critical issue, as it can provide higher strength and stiffness while poor dispersion is seen to decrease those properties. In the present work, the effect of three ultrasonic parameters (amplitude, time and cycle of sonication) on sonication technique for dispersing 1 wt.% nano-clay in polyester matrix was investigated. To disperse the nano-clay into the polyester matrix, sonication frequencies of 40% and 80%, sonication times of 0.5, 1 and 2 hours and pulse of 0.5 and 1 cycle were used. The effect of these ultrasonication parameters on water barrier and impact behavior of unfilled and filled glass fiber (GF)/polyester with nano-clay under dry, distilled and seawater conditions was studied. Results showed that, water absorption of nano-filled composites dispersed with all sonication parameters is lower than that of unfilled glass fiber/polyester composites immersed in distilled and seawater. Nano-clay filled GF/polyester composites showed an improvement in impact resistance under dry, distilled and seawater conditions with all sonication parameters. Among the used sonication parameters; time of 2 hours, amplitude of 40% and 0.5 cycle was found as the best parameter which resulted in the maximum enhancement in impact resistance, due to the addition of nano-clay to GF/polyester, of 8.2%, 14% and 19.6% under dry, distilled water and seawater conditions, respectively. Nonlinear minimization approach was exploited using MAPLE commercial software in order to find the suitable fit to the models of Fick and Langmuir. Diffusion coefficients for different sonication times were computed.

Simultaneous Oil Sono-Extraction And Sono-Transesterification (In Situ) Of Soybean And Sunflower Seeds For The Production Of Biodiesel

The cost of biodiesel production could be reduced by applying a simultaneous oil extraction and transesterification process (in situ). In situ sono-transesterification to allow direct production of biodiesel from soybean and sunflower seeds are presented in this study. All experiments were conducted using ultrasound (20kHz, 106W). In the sunflower case, the results showed a higher yield of extraction (94%) for a 1/5 (g/mL) ratio and one minute of sonication. In the soybean case, the extraction process is less efficient, reaching only 59% of the oil contained in the seed for a soybean/n-hexane ratio of 1/10 (g/mL) and one minute of sonication. Parameters such as the methanol/oil ratio, reaction time and catalyst concentration in the in situ sono-transesterification process of these vegetable seeds were also optimised in this study. In both cases, a percentage of conversion to biodiesel greater than 99% was achieved with just one minute of sonication.

Focused ultrasound ablation of solid tumors: Feasibility of planning tissue-selective treatments.

e15600 Background: Focused ultrasound (FUS) is a noninvasive, nonionizing, repeatable local ablative therapy that induces mechanical fractionation or thermal necrosis of a variety of solid tumors including hepatocellular carcinoma, prostate cancer, and desmoid fibromatosis. Recent feasibility studies in animal models have demonstrated the possibility of designing focused ultrasound treatments that are selective (e.g. spare healthy tissue, nerves, and blood vessels) due to differences in tissue and tumor mechanical properties. Given wide variation in individual tumor and patient characteristics, mechanics-based predictions of ablation zone features in different tissues under a range of FUS device settings are needed to permit personalized treatment planning. Methods: A finite difference computational method is used to simulate FUS ablation of tissues with variable mechanical properties (shear moduli of 0.6 – 200 kPa) under different FUS sonication parameters (frequency and peak pressure). The model calculates strain fields contributing to tissue ablation in FUS treatments which are used to predict ablation zone radii and boundary characteristics. Simulation predictions in model tissues are then compared to histology obtained from FUS-treated porcine tissue samples with similar mechanical properties. Results: The mechanical properties of model tissues and FUS treatment parameters have distinct effects on predicted minimum ablation zone radii. For example, smaller ablation zone radii are achieved in stiffer vessel wall than liver under given FUS sonication parameters. In each tissue, lower frequency and higher peak pressure FUS sonication predict a larger ablation zone. Combined variation of sonication frequency and peak pressure are found to achieve wider variation in ablation zone radius than previously achieved with frequency variation alone. Predicted ablation zone radii and boundary characteristics are consistent with the observed histology of FUS-treated tissues. Conclusions: Results show that simulations accounting for tissue mechanical properties and device settings can predict tissue selectivity and ablation zone characteristics observed in FUS procedures. This study demonstrates the potential of using noninvasive measurements of tissue and tumor properties obtained, for example, via shear wave elastography, in combination with micromechanical tissue ablation simulations to develop personalized, selective focused ultrasound treatments for solid tumors.