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A major concern in tissue biopsies with a needle is missing the most lethal clone of a tumor, leading to a false negative result. This concern is well justified, since needle-based biopsies gather tissue information limited to needle size. In this work, we show that molecular harvesting with electroporation, e-biopsy, could increase the sampled tissue volume in comparison to tissue sampling by a needle alone. Suggested by numerical models of electric fields distribution, the increased sampled volume is achieved by electroporation-driven permeabilization of cellular membranes in the tissue around the sampling needle. We show that proteomic profiles, sampled by e-biopsy from the brain tissue, ex vivo, at 0.5mm distance outside the visible margins of mice brain melanoma metastasis, have protein patterns similar to melanoma tumor center and different from the healthy brain tissue. In addition, we show that e-biopsy probed proteome signature differentiates between melanoma tumor center and healthy brain in mice. This study suggests that e-biopsy could provide a novel tool for a minimally invasive sampling of molecules in tissue in larger volumes than achieved with traditional needle biopsies. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) is an emerging technology for biomass processing and fractionation by electroporation of cell membrane. Nevertheless, PEF technology and devices require tailoring and adaptation for each specific type of biomass. Such an optimization requires convenient and adaptable laboratory systems, which will enable both electrical and mechanical parameters determination before process upscaling. In this work, we report on the design and development of a laboratory PEF system that allows applying for up to 4 kV, 1 kA pulses with 1–100 μ s and total power dissipation of 20 W and up to 25 kg of mechanical load. The design of an asymmetric voltage multiplying circuit allows for controlling pulse parameters for each pulse in series. Such an approach enables precise adaptation of PEF to the changing conductivity of the biomass, minimizing the total invested energy in the process. The system was tested on highly conductive marine macroalgae Ulva sp, a promising but challenging feedstock for the biorefinery. This work provides a design of an adaptable PEF device, important for biomass processing with electroporation. [ABSTRACT FROM AUTHOR]

Enhancing water diffusivity shortens meat processing time and saves energy and costs. One of the processes that can enhance water diffusivity in tissues is high-voltage, short-pulsed electric fields (PEF). However, for industrial PEF process development, there is a need in adaptable laboratory instruments. Here we report on a laboratory PEF generator, based on insulated-gate monopolar transistor switching, coupled with sliding positive electrode for the enhancement of water diffusivity in chicken breast muscle. The system generates rectangular monopolar pulses with a voltage amplitude up to 1000 V, current up to 160 A, pulse duration of 5 to 100 μs, and a frequency of pulse repetition of 1–16 Hz. The energy conversion efficiency of the developed PEF generator is 88%. We found that applying 120 pulses at 1000 V (~ 500 V mm−1), and a pulse duration of 50 μs at 1 Hz, on the chicken breast muscle, increased the effective diffusivity of water by 13–24% and reduced convective air drying time by 6.4–15.3%. These results provide new information on the design of laboratory equipment to improve and optimize meat pre-processing on a small scale. Flexible, small-scale PEF equipment is a necessary step for the industrial development of new processes which could reduce equipment size and process energy consumption in the meat industry. [ABSTRACT FROM AUTHOR]

Marine biorefineries, based on macroalgal (seaweed) feedstocks, could provide sustainable alternative sources of food, energy, and materials. Green macroalgae, with their unique chemical composition, can contribute to marine biorefinery systems associated with a wide range of potential products. This review discusses the challenge of developing industrially relevant and environmentally-friendly green seaweed biorefineries. First, we review potential products from green seaweeds and their co-production, the key element in an integrated biorefinery. Second, we discuss large-scale cultivation, hydrothermal treatments, fermentation, anaerobic digestion, and emerging green solvents, pulsed electric field, microwave, and ultrasound processing technologies. Finally, we analyse the main polysaccharides in green seaweeds: sulfated polysaccharides, starch, and cellulose, as products of a cascading biorefinery, with emphasis on applications and technological challenges. We provide a comprehensive state-of-the-art review of green seaweed as feedstock for the biorefinery, analysing opportunities and challenges in the field. [ABSTRACT FROM AUTHOR]

When high-amplitude, short-duration pulsed electric fields are applied to cells and tissues, the permeability of the cell membranes and tissue is increased. This increase in permeability is currently explained by the temporary appearance of aqueous pores within the cell membrane, a phenomenon termed electroporation. During the past four decades, advances in fundamental and experimental electroporation research have allowed for the translation of electroporation-based technologies to the clinic. In this review, we describe the theory and current applications of electroporation in medicine and then discuss current challenges in electroporation research and barriers to a more extensive spread of these clinical applications. [ABSTRACT FROM AUTHOR]

Tissue ablation is an essential procedure for the treatment of many diseases. In the last decade, a nonthermal tissue ablation using intensive pulsed electric fields, called nonthermal irreversible electroporation (NTIRE), has rapidly emerged. The exact mechanisms responsible for cell death by NTIRE, however, are currently unknown. Nevertheless, the technique's remarkable ability to ablate tissue in the proximity of larger blood vessels, to preserve tissue architecture, short procedure duration, and shortened postoperative recovery period rapidly moved NTIRE from bench to bed side. This work provides an overview on the development of NTIRE, its current state-of-the-art, challenges, and future needs. [ABSTRACT FROM PUBLISHER]

The design of effective electroporation protocols for molecular delivery applications requires the determination of transport parameters including diffusion coefficient, membrane resealing, and critical electric field strength for electroporation. The use of existing technologies to determine these parameters is time-consuming and labor-intensive, and often results in large inconsistencies in parameter estimation due to variations in the protocols and setups. In this work, we suggest using a set of concentric electrodes to screen a full range of electric field strengths in a single test to determine the electroporation-induced transmembrane transport parameters. Using Calcein as a fluorescent probe, we developed analytical methodology to determine the transport parameters based on the electroporation-induced pattern of fluorescence loss from cells. A monolayer of normal human dermal fibroblast (NHDF) cells were pre-loaded with Calcein and electroporated with an applied voltage of 750 V with 10 and 50 square pulses with 50 μs duration. Using our analytical model, the critical electric field strength for electroporation was found for the 10 and 50 pulses experiments. An inverse correlation between the field strength and the molecular transport time decay constant, and a direct correlation between field strength and the membrane permeability were observed. The results of this work can simplify the development of electroporation-assisted technologies for research and therapies. [ABSTRACT FROM AUTHOR]

Highlights • Method for selective allergens extraction with pulsed electric fields. • Protein extraction with the pulsed electric field from Ulva sp. was optimized. • Allergy assessment of proteins extracted from the seaweed Ulva sp. • Proteomic analysis of Ulva sp. Abstract Extraction of protein from macroalgae, currently defined as "novel food", is challenging and limited information about the health impacts of these proteins is available. Here, we report on a non-thermal, chemical-free green macroalgae Ulva sp. protein extraction by osmotic shock combined with pulsed electric fields (PEF) followed by hydraulic pressure. The extracted proteins were identified and annotated to allergens using sequence similarity. The allergenicity potential of PEF extracted proteins was compared to osmotic shock extracts and complete Ulva sp. proteome, extracted with the thermochemical method. The PEF extracts contained 'superoxide dismutase' (SOD), a known food allergen, osmotic shock extract contained 'troponin C', and thermochemical extract contained two additional potential food allergens 'aldolase A' and 'thioredoxin h'. This study shows an importance and the need for deep investigation of algal proteins and protein extraction technology health impacts prior to large-scale release to the market of "novel food" derived proteins. [ABSTRACT FROM AUTHOR]

Among all biomass constituents, the ashes are major hurdles for biomass processing. Ashes currently have low market value and can make a non-negligible fraction of the biomass dry weight significantly impacting its further processing by degrading equipment, lowering process yield, inhibiting reactions and decreasing products qualities. However, most of the current treatments for deashing biomass are of poor efficiency or industrial relevance. This work is the first report on the use of Pulsed Electric Field (PEF) to enhance deashing of biomass from a high ash content green marine macroalga, Ulva sp., using hydraulic pressing. By inducing cell permeabilization of the fresh biomass, PEF was able to enhance the ash extraction from 18.4% (non-treated control) to 37.4% of the total ash content in average, significantly enhancing the extraction of five of the major ash elements (K, Mg, Na, P and S) compared to pressing alone. [ABSTRACT FROM AUTHOR]

Marine macroalgae are an attractive source of alternative protein. However, protein extraction from macroalgae is challenging. In this work, we investigated a combination of enzymatic cell wall degradation and high voltage Pulsed Electric Fields (PEF), to enhance yields of water-soluble-protein extraction from the green marine macroalga Ulva sp. The combined process showed a considerably higher protein extraction yield (19.6 ± 0.33%) compared to that of PEF alone (10.8 ± 0.37%) and enzyme pretreatment alone (9.7 ± 0.42%). Moreover, the water-soluble-protein extract obtained by PEF, which followed enzymatic cell wall degradation, had significant antioxidant activity. These results indicate that PEF combined with enzymatic pretreatment could contribute to protein extraction yields from Ulva sp., as a part of sustainable seaweed biorefinery. Although several previous works reported on methods for protein extraction from seaweeds for food application, the commercialization of the seaweed proteins is challenging due to multiple challenges in the extraction process development. In this work we show that a combination of enzymes for cell wall degradation with high voltage pulsed electric fields for membrane permeabilization lead to higher yields of water-soluble proteins. Both enzyme treatment and PEF are scalable processes, which do not modify proteins chemically, potentially leading to higher quality of the extract in comparison to standard alkaline extraction with a need to treat chemical waste. • Protein extraction from macroalgae Ulva sp. is challenging. • A combination of cellulase with Pulsed Electric Fields to extract protein was investigated. • The combined process showed 19.6 ± 0.33% protein extraction yield. • The water-soluble-protein extract had significant antioxidant activity. • The specific energy consumed relative to the wet mass of Ulva sp. was 79.1 ± 1.44 kJ kg−1 [ABSTRACT FROM AUTHOR]

Macroalgae are potential feedstock for biorefineries. However, integration of macroalgae into biorefinery network requires new processing technologies that will lead to energy efficient and zero waste conversion of macroalgae biomass into food, chemicals and fuels. Here we report on the selective extraction of proteins from green macroalgae from Ulva genus by electroporation with energy efficient pulsed electric field (PEF) process. We show that application of 75 pulses with an average electric field strength of 2.964 ± 0.007 kV cm − 1 , and pulse duration 5.70 ± 0.30 μs, delivered at approximately 0.5 Hz, combined with hydraulic pressing of the treated samples for 5 min with force of 45 daN cm − 2 led to the total protein concentration of 59.13 ± 3.82 μg mL − 1 in the extracted juice. The final temperature of the extracted juice was 35.50 ± 2.02 °C. The energy consumption of the process is 251 ± 3 kWh kg − 1 of protein. We show that PEF process is selective and its extraction efficiency and damage are protein specific. [ABSTRACT FROM AUTHOR]

Carnosine (β-alanyl-L-histidine) and its methylated counterpart anserine (β-alanyl-1-methylhistidine) are important functional dipeptides found in various vertebrates' tissues. In this study, we identified the critical parameters of pulsed electric fields (PEF), coupled to mechanical pressing, followed by incubation in water up to 240 min for the extraction of these bioactive dipeptides from chicken meat. We show that PEF improves the kinetics of anserine and carnosine release to water by 7 to 53%, compared to the same water extraction process without PEF when the incubation time is below 120 min. A fractional factorial design showed that the incubation time in the water, after PEF pretreatment, had the most significant effect on dipeptides extraction. The maximum achieved total protein yield was 15.5 mg g fresh weight(FW) -1 after 120 min incubation in water. The maximum carnosine extraction yield was 7.48 mg g FW −1 with a maximum anserine extraction yield of 3.05 mg g FW −1. The specific energy yield of extraction of protein, carnosine, and anserine was 488.16 mg J−1, 39.43 mg J−1, and 131.63 mg J−1 respectively. The developed method is scalable and could be further explored to extract bioactive compounds from animal tissues. • Extraction of functional dipeptides from chicken meat by inducing electroporation. • Pulsed electric field treatments could enhance extraction yields of carnosine and anserine. • Study on the impact of process parameters revealed crucial factors to consider. • Potential for value-addition from animal tissues by low-energy scalable PEF technology [ABSTRACT FROM AUTHOR]

The present study analyses the effects of low intensity pulsed electric fields (PEFs), coupled to mechanical press dewatering on meat drying with air convection. Process parameter optimization using Taguchi design showed that the number of pulses had most significant effect on meat dewatering. A maximum effective diffusivity of 2.31 × 10−9 m2 s−1 was observed for PEF assisted drying of chicken meat at 80 °C. An overall energy saving of 933.18 ± 22 J g−1 was observed for drying at 60 °C when the meat was treated with a voltage of 75 V with initial distance between electrodes of 6.917 ± 0.38 mm, pulse length 7 ms, 300 pulses with a frequency of 2 Hz under 125.44 kPa continuous mechanical load. Our study suggests that PEF coupled to mechanical dewatering saves energy in conventional meat drying with air convection. Such a strategy could provide a scalable model for PEF assisted drying of various food products with higher energy efficiency and improved diffusivity. • Utilization of pulsed electric fields to reduce energy consumption for drying of chicken meat with maximum energy savings of 933.18 ± 22 J g−1. • Application of Taguchi methodology for optimization of process parameters. • Effect of various drying temperatures on the water diffusivity with ~40% water removal using PEF treatment. • Sustainable and energy-efficient process for manufacture of dried meat products. Industrial Relevance. Drying is an energy intensive operation that easily accounts for up to 15% of all industrial energy usage, often with relatively low thermal efficiency in the range of 25–50%. In conventional thermal drying methods, flavor, color, and nutritional loss (vitamin degradation and loss of amino acids) occur because of thermal degradation, which decreases the drying rate and rehydration ratio. For this reason, new technologies should be used to obtain better quality dried meat and dried meat products. The present study demonstrates the utility of PEF treatment for drying of food items in an energy efficient manner. The results indicated that PEF could assist in drying by reducing the water content. The process is low energy consuming thereby increasing its utility for a variety of food products. The methods used are scalable and could be used for increased shelf life of various food items. [ABSTRACT FROM AUTHOR]

Optimization of protocols is required for each specific type of biomass processed by electroporation of the cell membrane with high voltage pulsed electric fields (PEF). Such optimization requires convenient and adaptable laboratory systems, which will enable determination of both electrical and mechanical parameters for successful electroporation and fractionation. In this work, we report on a laboratory PEF system consisting of a high voltage generator with a novel asymmetric voltage multiplying architecture and a treatment chamber with sliding electrodes. The system allows applying pulses of up to 4 kV and 1 kA with a pulse duration between 1 μs and 100 μs. The allowable energy dissipated per pulse on electroporated biomass is determined by the conditions for cooling the biomass in the electroporation cell. The device was tested on highly conductive green macroalgae from Ulva sp., a promising but challenging feedstock for the biorefinery. Successful electroporation was confirmed with bioimpedance measurements. Seaweed biomass is an emerging feedstock for biorefineries with already 30 million tons per year of global industrial production. However, most of the biomass produced today is lost. Pulsed electric field (PEF) extraction could allow saving energy on biomass drying, deashing and it could allow extracting various organic compounds. However, the parameters needed to seaweed biomass treatment with PEF are not known and will differ from species to species. Furthermore, very high salt content challenges most of the available laboratory PEF devices, limiting the ability for parameters optimization in the lab. The developed laboratory scale PEF system coupled to bioimpedance measurement provides a necessary set of tools and methods for PEF parameters optimization required for process scale-up. • Pulsed electric field generator with gravitation press electrodes was developed for seaweed biomass electroporation. • Asymmetric voltage multiplying architecture allows to control the voltage of each pulse. • PEF parameters 4 kV, 1 kA, 1–100 μs duration and total power dissipation of 20 W • Macroalgae Ulva sp. was treated with 124 ± 12 V mm−1, pulse duration 50 μs, pulse number 50, frequency 3 Hz. • Electroporation of the biomass was confirmed with bioimpedance measurements. [ABSTRACT FROM AUTHOR]

• Green macroalgae Ulva sp. was cultivated 15 km offshore. • A positive growth rate of offshore cultivated Ulva sp. was measured during 7 months of cultivation. • A positive yield was measured during 7 months of cultivation. • Pulsed electric field dewatering of Ulva sp. saves energy on convective air drying. Offshore macroalgae biomass production is a promising, yet challenging, pathway to provide feedstock for biorefineries. In this work, a device and a process for dewatering offshore grown biomass of the green macroalgae Ulva sp. using high-voltage pulsed electric fields (PEF) was developed. Ulva sp. was cultivated attached to fish cages 15 km offshore. Increasing the applied voltage from 250 V to 500 V and invested PEF energy from 9.3 ± 0.4 J g−1 FW to 54.6 ± 0.2Jg−1 FW increased the extracted water from 0.033 ± 0.006 g Water g−1 FW to 0.150 ± 0.031 g Water g−1 FW. The energy consumption to achieve similar moisture content with air convection drying was lower by 78.73 ± 10.41 (JgFW−1) for 250 V and 339.31 ± 48.01 (JgFW−1) for 500 V, pulse duration 50 µs, pulse number 50, pulse repetition frequency 3 Hz. PEF leads to biomass compression of 8.45 ± 1.72% for 250 V protocol and 25.66 ± 2.53% for 500 V protocol. In addition, PEF leads to the reduction of water diffusivity of 18–19% in the treated biomass, reducing air drying kinetics. [ABSTRACT FROM AUTHOR]