Membranes In Aqueous Solutions Research Articles

Polyoxometalate Clusters Confined in Reduced Graphene Oxide Membranes for Effective Ion Sieving and Desalination.

Efficient 2D membranes play a critical role in water purification and desalination. However, most 2D membranes, such as graphene oxide (GO) membranes, tend to swell or disintegrate in liquid, making precise ionic sieving a tough challenge. Herein, the fabrication of the polyoxometalate clusters (PW12) intercalated reduced graphene oxide (rGO) membrane (rGO-PW12) is reported through a polyoxometalate-assisted in situ photoreduction strategy. The intercalated PW12 result in the interlayer spacing in the sub-nanometer scale and induce a nanoconfinement effect to repel the ions in various salt solutions. The permeation rate of rGO-PW12 membranes are about two orders of magnitude lower than those through the GO membrane. The confinement of nanochannels also generate the excellent non-swelling stability of rGO-PW12 membranes in aqueous solutions up to 400 h. Moreover, when applied in forward osmosis, the rGO-PW12 membranes with a thickness of 90nm not only exhibit a high-water permeance of up to 0.11790 L m-2 h-1 bar-1 and high NaCl rejection (98.3%), but also reveal an ultrahigh water/salt selectivity of 4740. Such significantly improved ion-exclusion ability and high-water flux benefit from the multi-interactions and nanoconfinement effect between PW12 and rGO nanosheets, which afford a well-interlinked lamellar structure via hydrogen bonding and van der Waals interactions.

Engineered nanoparticles as Selinexor drug delivery systems across the cell membrane and related signaling pathways in cancer cells

In the present work, molecular dynamics simulation is applied to evaluate the drug carrier efficiency of graphene oxide nanoflake (GONF) for loading of Selinexor (SXR) drug as well as the drug delivery by 2D material through the membrane in aqueous solution. In addition, to investigate the adsorption and penetration of drug-nanocarrier complex into the cell membrane, well-tempered metadynamics simulations and steered molecular dynamics (SMD) simulations were performed. Based on the obtained results, it is evident that intermolecular hydrogen bonds (HBs) and π-π interactions play a significant role in expediting the interaction between drug molecules and the graphene oxide (GO) nanosheet, ultimately resulting in the formation of a stable SXR-GO complex. The Lennard-Jones (L-J) energy value for the interaction of SXR with GONF is calculated to be approximately −98.85 kJ/mol. In the SXR-GONF complex system, the dominant interaction between SXR and GONF is attributed to the L-J term, resulting from the formation of a strong π−π interaction between the drug molecules and the substrate surface. Moreover, our simulations show by decreasing the distance of GONF with respect to cell membrane, the interaction energy of GONF-membrane significantly decrease to −1500 kJ/mol resulting in fast diffusion of SXR-GONF complex toward the bilayer surface that is favored opening the way to natural drug nanocapsule.

“Ion-cage” structure of graphene oxide membranes with stable interlayer spacings towards efficient desalination

Multilayered graphene oxide (GO) membrane with sub-nanometer channels is an ideal candidate for desalination. However, excluding small ions using GO-based membranes in the pressured filtration processes remains a great challenge due to the tortuous transport paths of laminates and their water-swelling characteristic. In our previous work, we developed the cation-controlled theory to precisely regulate the interlayer spacing of GO membranes in aqueous solutions. In this work, we proposed an “ion-cage” strategy to enhance the stability (anti-swelling) of the K-controlled GO (icGO-K) membrane for achieving efficient desalination. The icGO-K membrane, coated with positively charged polyethyleneimine (PEI) on its upper and lower surfaces, immobilized intercalated cation K+ between the laminates by electrostatic repulsion to maintain the stability of the confined interlayer spacing. The icGO-K membrane demonstrated superior rejection of 95.3 %, 83.2 %, 81.8 %, and 70.7 % for MgCl2, MgSO4, NaCl, and Na2SO4 while maintaining competitive permeance of ∼ 3.5 L m-2h−1 bar−1 in the desalination process. More importantly, the icGO-K membrane exhibited ultra-long desalination stability up to 720 h. The enhanced performance can be attributed to the synergistic effect of the confined interlayer spacing and surface electrostatic repulsion. Overall, this work provides attractive strategy to fabricate fine-tuning 2D laminate nanochannels for high efficiency of desalination application.

Removing the trace organic compounds using graphene oxide nanocomposite membrane cross-linked by melamine

In this study graphene oxide (GO) based active layer was formed on microfiltration substrate to prepared thin file composite forward osmosis (TFC-FO) membrane with high rejection to pesticides. The ideal GO-based membrane should have high stability, durability, and selectivity. To improve the stability of GO based TFC membrane in aqueous solution the GO nanosheets were cross-linked with melamine monomer. An anchoring carbon-nitrogen covalent bond between the GO nanosheets and melamine molecules is thought to supplement to form the nanocomposite structure. As a result of the configuration of melamine molecules within the channel region, a nanocomposite structure has been formed which provides an optimal condition for resisting the flow of hydrated salt ions but creating a pathway for water molecules to flow. According to the FO tests with different draw solutions against DI water feed, the prepared GOM membranes (GO based active layer crosslinked with melamine) showed best performance with trisodium citrate (TSC) draw solution. In the FO model, a water flux of 18.1 LMH was obtained using TSC, which was 970% higher than the NaCl, while the reverse solute diffusion was reduced by 1100%. The effect of GO thickness on FO performance was also studied, by changing GO solution volume during active layer coating (10, 15 and 20 mL GO solution with concentration of 0.1 mg/mL). Result showed that by increasing the GO thickness the water flux increased from 13.7 LMH in GOM.10 to 18.1 in GOM.15. In addition, the nanocomposite membrane shows high rejection against of both diazinon (99.4%) and atrazine (97.3%). In relation to these results, it can be concluded that GO-based membranes can provide clean water in the FO process as an alternative to polymer-based TFC membranes.

Interaction of Macromolecular Chain with Phospholipid Membranes in Solutions: A Dissipative Particle Dynamics Simulation Study.

The interaction between macromolecular chains and phospholipid membranes in aqueous solution was investigated using dissipative particle dynamics simulations. Two cases were considered, one in which the macromolecular chains were pulled along parallel to the membrane surfaces and another in which they were pulled vertical to the membrane surfaces. Several parameters, including the radius of gyration, shape factor, particle number, and order parameter, were used to investigate the interaction mechanisms during the dynamics processes by adjusting the pulling force strength of the chains. In both cases, the results showed that the macromolecular chains undergo conformational transitions from a coiled to a rod-like structure. Furthermore, the simulations revealed that the membranes can be damaged and repaired during the dynamic processes. The role of the pulling forces and the adsorption interactions between the chains and membranes differed in the parallel and perpendicular pulling cases. These findings contribute to our understanding of the interaction mechanisms between macromolecules and membranes, and they may have potential applications in biology and medicine.

Shaping membrane interfaces in lipid vesicles mimicking the cytoplasmic leaflet of myelin through variation of cholesterol and myelin basic protein contents

Myelin basic protein (MBP) is an intrinsically disordered protein and in the central nervous system (CNS) mainly responsible for connecting the cytoplasmic surfaces of the multilamellar, compact myelin. Increased posttranslational modification of MBP is linked to both, the natural development (from adolescent to adult brains) of myelin, and features of multiple sclerosis. Here, we study how a combination of this intrinsically disordered myelin protein with varying the natural cholesterol content may alter the characteristics of myelin-like membranes and interactions between these membranes. Large unilamellar vesicles (LUVs) with a composition mimicking the cytoplasmic leaflet of myelin were chosen as the model system, in which different parameters contributing to the interactions between the lipid membrane and MBP were investigated. While we use cryo-transmission electron microscopy (TEM) for imaging, dynamic light scattering (DLS) and electrophoretic measurements through continuously-monitored phase-analysis light scattering (cmPALS) were used for a more global overview of particle size and charge, and electron paramagnetic resonance (EPR) spectroscopy was utilized for local behavior of lipids in the vesicles' membranes in aqueous solution. The cholesterol content was varied from 060 % in these LUVs and measurements were performed in the presence and absence of MBP. We find that the composition of the lipid layers is relevant to the interaction with MBP. Not only the size, the shape and the aggregation behavior of the vesicles depend on the cholesterol content, but also within each membrane, cholesterol's freedom of movement, its environmental polarity and its distribution were found to depend on the content using the EPR-active spin-labeled cholesterol (CSOSL). In addition, DLS and EPR measurements probing the transition temperatures of the lipid phases allow a correlation of specific behavior with the human body temperature of 37 °C. Overall, our results aid in understanding the importance of the native cholesterol content in the healthy myelin membrane, which serves as the basis for stable and optimum protein-bilayer interactions. Although studied in this specific myelin-like system, from a more general and materials science-oriented point of view, we could establish how membrane and vesicle properties depend on cholesterol and/or MBP content, which might be useful generally when specific membrane and vesicle characteristics are sought for.

Coarse-grained molecular dynamics simulation of cation distribution profiles on negatively charged lipid membranes during phase separation.

Revealing the ion distributions on a charged lipid membrane in aqueous solution under the influence of long-range interactions is essential for understanding the origin of the stability of the bilayer structure and the interaction between biomembranes and various electrolytes. However, the ion distributions and their dynamics associated with the phase separation process of the lipid bilayer membrane are still unclear. We perform coarse-grained molecular dynamics simulations to reveal the Na+ and Cl- distributions on charged phospholipid bilayer membranes during phase separation. During the phase separation, cations closely follow the position of negatively charged lipids on a microsecond timescale and are rapidly redistributed parallel to the lipid bilayer. In the homogenous mixture of zwitterionic and negatively charged lipids, cations weakly follow negatively charged lipids, indicating the strong interaction between cations and negatively charged lipids. We also compare cation concentrations as a function of surface charge density obtained by our simulation with those obtained by a modified Poisson-Boltzmann theory. Including the ion finite size makes the statistical results consistent, suggesting the importance of the ion-ion interactions in aqueous solution. Our simulation results advance our understanding of ion distribution during phase separation.

Nanocellulose-intercalated MXene NF membrane with enhanced swelling resistance for highly efficient antibiotics separation

Two-dimensional (2D) nanomaterial-based membranes display attractive properties in molecular separation and transport, which holds their great promise for a host of applications. However, notorious swelling problem of 2D membranes result in unsatisfactory molecular/ions sieving performance, and the enhancement of structural stability for 2D membranes in aqueous solution is still challenging. Herein, we demonstrate how to efficiently stabilize the Ti3C2Tx MXene laminar architecture by the insertion of flexible and hydrophilic carboxylated cellulose nanofibers (CNFs). The importing of CNFs not only acted as a bridge to combine the adjacent 2D Ti3C2Tx sheets and enhance mechanical strength, but also assumed the role of pillar to fix the interlayer distance effectively and improve the anti-swelling properties of Ti3C2Tx membrane. Moreover, the intercalation of nanocelluloses into the interlayer of delaminated Ti3C2Tx is able to distinctly increase the interlayer spacing and create more open gaps for fast and selective molecular transport. When applied in antibiotics separative filtration process, the resultant membrane exhibits outperformed anti-swelling properties in water environment up to 76 h and simultaneously possesses satisfactorily high selectivity of antibiotics (∼99.0 % for azithromycin) with unprecedentedly high pure water permeance (∼26.0 L m−2h−1bar−1). Such 2D membranes can be easily fabricated by a facile and patternable vacuum-assisted filtration and nanocellulose induced self-assembly strategy, which holds great potential for their scalability that are applicable to many applications such as seawater desalination, industrial wastewater treatment and remediation of aquatic environment.

Highly Selective Potentiometric Sensing of Biologically Relevant Pyrophosphate and Lysophosphatidic Acid Using N-Alkyl/Aryl Ammonium Resorcinarenes/Extended-Resorcinarenes as Ionophores.

The ionophore properties of four kinds of N-alkyl/aryl ammonium resorcinarenes and extended-resorcinarenes were inspected for the first time to fabricate polymeric membrane electrodes for determination of biologically relevant pyrophosphate (PPi) and lysophosphatidic acid (LPA). The proposed ion selective electrodes (ISEs) showed significant preference for PPi and LPA with significant selectivity pattern differences from the Hofmeister series. To gain further insight into the performances of the developed ISEs, the binding constants of ionophore-anion complexes in the plasticized membrane phase were investigated, along with the optimized geometries and calculated electrostatic potential. Nernstian potential responses with good reversibility to target anions can be observed when shifting the optimized membranes in aqueous solutions in the concentration range from 10-6.5 to 10-2.3/10-2.2 M. Moreover, potentiometric sensings of PPi and LPA in mineral water and artificial serum were achieved in low μM concentration range, demonstrating their promising real-world applications. These results provide a promising avenue for the development of polymeric membrane electrodes for biological relevant anions and will broaden the scope of potentiometric sensing.

Highly stable and permeable graphene oxide membrane modified by carbohydrazide for efficient dyes separation

As natural resources become more and more limited, it is exceptionally essential to decrease energy consumption in membrane separation processes, which makes membranes with ultra-high water permeance increasingly expected. Graphene oxide (GO) membranes have exhibited an unsurpassed future for wastewater purification. However, it is two key challenges to greatly increase the water permeance while retaining the removal efficiency of contaminants and improve the enduring stability of membranes in aqueous solution. In this work, the membranes with ultrafast water permeability were prepared by self-assembly vacuum filtration method using carbohydrazide (CHZ) as reducing and cross-linking agent. The obtained lamellar rGO/CHZ nanofiltration membranes exhibited water permeance bigger than 1600 L m-2h−1 bar−1, and outstanding separation efficiency, e.g., Congo Red (CR), Malachite Green (MG), and Crystal Violet (CV) removal rate of 99%. More importantly, the composite membrane exhibited efficiently selective separation of various mixed dyes. Such as binary mixed dyes of MG/MO, the removal rate of MG is 99%, while the removal rate of MO is merely 23%. In addition, the membrane still showed excellent stability after long-term immersion in solutions of various pH values. The separation performance in terms of complete rejection of single dyes and selective filtration of mixed dyes makes them one of the promising materials for dye separation, purification, and reuse.

Biomimetic nanobubbles for triple-negative breast cancer targeted ultrasound molecular imaging

Triple-negative breast cancer (TNBC) is a highly heterogeneous breast cancer subtype with poor prognosis. Although anatomical imaging figures prominently for breast lesion screening, TNBC is often misdiagnosed, thus hindering early medical care. Ultrasound (US) molecular imaging using nanobubbles (NBs) capable of targeting tumor cells holds great promise for improved diagnosis and therapy. However, the lack of conventional biomarkers in TNBC impairs the development of current targeted agents. Here, we exploited the homotypic recognition of cancer cells to synthesize the first NBs based on TNBC cancer cell membrane (i.e., NBCCM) as a targeted diagnostic agent. We developed a microfluidic technology to synthesize NBCCM based on the self-assembly property of cell membranes in aqueous solutions. In vitro, optimal NBCCM had a hydrodynamic diameter of 683 ± 162 nm, showed long-lasting US contrast enhancements and homotypic affinity. In vivo, we demonstrated that NBCCM showed increased extravasation and retention in a TNBC mouse model compared to non-targeted NBs by US molecular imaging. Peak intensities and areas under the curves from time-intensity plots showed a significantly enhanced signal from NBCCM compared to non-targeted NBs (2.1-fold, P = 0.004, and, 3.6-fold, P = 0.0009, respectively). Immunofluorescence analysis further validated the presence of NBCCM in the tumor microenvironment. Circumventing the challenge for universal cancer biomarker identification, our approach could enable TNBC targeting regardless of tumor tissue heterogeneity, thus improving diagnosis and potentially gene/drug targeted delivery. Ultimately, our approach could be used to image many cancer types using biomimetic NBs prepared from their respective cancer cell membranes.

Sandwich layered double hydroxides with graphene oxide for enhanced water desalination

Layered double hydroxides (LDHs) are a class of two-dimensional (2D) clay compounds that consist of positively charged host layers and exchangeable interlayer anions. The stability of their assemblies in aqueous environment is a challenge due to the extremely high hydrophilicity, which limits their use in membrane-based technologies. Here, we propose a graphene oxide (GO) armour protection strategy to substantially improve the stability of LDH membranes in aqueous solution. The sandwich structured GO/LDH/GO membranes (GLGMs) possess a negative-positive-negative charge heterojunction in the vertical direction that effectively blocks the transport of both cations and anions, i.e., NaCl, but allows the permeation of water molecules. Following this mechanism, the GLGMs are used for desalination in a forward osmosis mode. A high rejection rate of over 95.2% for NaCl and water flux of over 2.1 L m−2 h−1 are achieved with simulated seawater.

Preparation of Stable Hydrophilic Polyethyleneimine Cross-Linked Graphene Oxide/Titanium Dioxide Membranes for Dye Separation

An excellent novel laminar and hierarchical polyethyleneimine cross-linked graphene oxide/titanium dioxide (GO–TiO2–PEI) membrane was successfully prepared by vacuum filtration technology using polyethyleneimine (PEI) as the cross-linking agent and a GO–TiO2 nanocomposite as the substrate. The resultant membrane (GO–TiO2–PEI) displayed a favorable antifouling performance with bovine serum albumin (BSA) and showed good hydrophilicity and wettability, with a static water contact angle of 13.2∘. The stability of the GO–TiO2–PEI membrane in aqueous solution obviously improved with the cross-linking of PEI compared with that of the GO and GO–TiO2 membranes. The GO–TiO2–PEI membrane also exhibited a satisfactory water flux of 48.6[Formula: see text]L m[Formula: see text] h[Formula: see text] bar[Formula: see text]. The GO–TiO2–PEI membrane exhibited a good performance for effectively separating different dyes including methylene blue (MB), rhodamine B (RB), methyl orange (MO), sunset yellow (SY), new coccine (NC) and amaranth. All the above results suggested that the GO–TiO2–PEI membrane could be used as an excellent stable hydrophilic membrane for efficiently separating dyes from aqueous solution.

A Novel Strategy to Fabricate Cation-Cross-linked Graphene Oxide Membrane with High Aqueous Stability and High Separation Performance.

Graphene oxide (GO) membranes have shown enormous promise in desalination and molecular/ionic sieving. However, the instability of GO membranes in aqueous solutions seriously hinders their practical applications. Herein, we report a novel and simple strategy to fabricate stable GO membranes in water-based environments through the insertion of various metal cations from metal foils (e.g., copper (Cu), iron (Fe), nickel (Ni), and zinc (Zn) foils) and natural deposition. Based on the cation-π, coordination, and electrostatic interaction between metal cations and GO nanosheets, the aqueous stability and mechanical strength of the membranes are significantly improved. The permeation rates for acetone, toluene, and p-xylene molecules across the GO membrane cross-linked by copper ions with a deposition time of 24 h are 0.966, 0.074, and 0.100 mol m-2 h-1, respectively. Moreover, this membrane displays excellent separation performance, and the separation factor of K+/Mg2+ is up to 68.8 in mono-/multivalent metal cation sieving, which indicate the effective molecular/ionic sieving performance. Meanwhile, the ionic sieving of the GO membrane cross-linked by copper ions has excellent repeatability and long-term stability. The versatility of this natural deposition strategy to fabricate GO membranes cross-linked by metal cations is investigated by using Fe foil, Zn foil, and Ni foil as well as other porous substrates such as polyvinylidene fluoride (PVDF), polyethersulfone (PES), and nylon membranes and filter paper. This fabrication strategy also enables low-cost preparation of large-area GO membranes. Therefore, GO membranes cross-linked by metal cations and prepared by this simple metal cation incorporation strategy have large potential application for molecular/ionic sieving in various solution systems.

Current–Voltage Characteristics of SiN Membranes in Solution

Recently, the dielectric breakdown of insulating membranes in aqueous solution has been utilized to fabricate nanopore sensors for various molecular detection applications. Generally, the breakdown...

Effect of cations on stabilizing graphene oxide membranes in aqueous solutions

Owing to the unique layer structures and efficient water transport, graphene oxide membranes (GOMs) have shown great promise in molecular and ion separation. In the above application fields, the stability of GOMs in aqueous solutions is the most essential requirement. In this paper, vortex shaking experiments and XRD characterization were carried out to test and illustrate the stability of GOMs in different solutions. Normally, when dry GOMs were immersed in aqueous solutions, the water molecules could rapidly enter layer space and enlarge the interlayer spacings (d-spacings), thus reducing the stability of GOMs in aqueous solutions. However, it was also found that the ions in aqueous solutions could play a positive role in restraining the d-spacings and stabilizing the GOMs. For monovalent cations (for example, H+ and Na+), high concentrations were required to guarantee the good stability of GOMs, which could be explained by the theory of electrostatic double layer. In contrast, low concentrations of divalent or trivalent cations (for example, Sr2+, UO22+ and Eu3+) could also efficiently crosslink the graphene oxide sheets, thus enhancing the stability of GOMs. Based on these results, to ensure the stability in practical application, a method of modifying original GOMs by 1 mM Eu3+ was proposed and verified by sucrose and metal ions permeation experiments. The results indicated that the modified GOMs could keep stable and be qualified to achieve selective separation.

Nanocrystalline Cellulose/Polyvinylpyrrolidone Fibrous Composites Prepared by Electrospinning and Thermal Crosslinking

Nanocellulose/polyvinylpyrrolidone (nCel/PVP) fibrous composite materials containing rod-like nanocrystalline cellulose particles with the lengths varying in the range from 100 to 2000 nm were prepared by using DC electrospinning. The particle size had a strong effect on the precursor viscosity, process efficiency, and resulting fiber diameter. The thermal crosslinking of nCel/PVP composite nanofibers with up to 1.0 : 8.0 nCel/PVP weight ratio resulted in fibrous membranes with textural, air transport, and mass swelling properties varying significantly with the size of cellulose particles. The presence of nCel particles increased the oxidation resistance of PVP during the crosslinking and affected the morphological changes of nCel/PVP fibrous membranes in aqueous solutions. Particles with the smallest size improved the strength of the membrane but decreased its mass swelling capacity, whereas the larger particles led to a more porous and flexible, but mechanically weaker, membrane structure with a higher swelling ability. Thus, by using the nCel particles of different size and shape, the properties of nCel/PVP composite fibrous membranes can be tailored to a specific application.

Photolysis Mechanism of p-Nitrophenol by Nitrocellulose Membrane in Aqueous Solution

To investigate the potential application of nitrocellulose membrane (NCM) in water treatment, this study examined the photolysis of p-nitrophenol, with NCM as the source of reactive oxygen species. Effects of solution pH, light conditions, and water dissolved substances on p-nitrophenol photolysis were investigated, and possible mechanisms were discussed. The results demonstrated that the quantum yield for hydroxyl radicals from the NCM was 1.30×10-4, which is approximately 1.86 times higher than that from TiO2. The photolysis rate of p-nitrophenol in the presence of NCM was 0.0055 min-1, which is much higher than that in pure water (9.52×10-4 min-1). This promotion was mainly caused by photo-induced generation of ·OH on NCM surface under light, in which UVA plays an important role in photolysis. The photolysis rate of p-nitrophenol increased with the increase of light intensity and membrane area. Acidic solution (pH=2.0) was preferred for the degradation of p-nitrophenol, with a photolysis rate of 0.0165 min-1; the corresponding degradation of p-nitrophenol exceeded 90% in 120 min. The effects of dissolved substances on photolysis were significantly different. NO3- promoted photolysis by generation of ·OH, and dissolved organic matter decreased photolysis through light attenuation. The intermediate products of gas chromatography-mass spectrometry analysis mainly included phenol, hydroquinone, malonic acid, and oxalic acid, and the possible photolysis pathway was given accordingly.

Ultra-facile aqueous synthesis of nanoporous zeolitic imidazolate framework membranes for hydrogen purification and olefin/paraffin separation

An ultra-facile one-step method is discovered to synthesize defect-free ZIF-8 molecular sieve membranes in aqueous solution at room temperature for exceptional gas separation.

Tracking Lysosome Migration within Chinese Hamster Ovary (CHO) Cells Following Exposure to Nanosecond Pulsed Electric Fields.

Above a threshold electric field strength, 600 ns-duration pulsed electric field (nsPEF) exposure substantially porates and permeabilizes cellular plasma membranes in aqueous solution to many small ions. Repetitive exposures increase permeabilization to calcium ions (Ca2+) in a dosage-dependent manner. Such exposure conditions can create relatively long-lived pores that reseal after passive lateral diffusion of lipids should have closed the pores. One explanation for eventual pore resealing is active membrane repair, and an ubiquitous repair mechanism in mammalian cells is lysosome exocytosis. A previous study shows that intracellular lysosome movement halts upon a 16.2 kV/cm, 600-ns PEF exposure of a single train of 20 pulses at 5 Hz. In that study, lysosome stagnation qualitatively correlates with the presence of Ca2+ in the extracellular solution and with microtubule collapse. The present study tests the hypothesis that limitation of nsPEF-induced Ca2+ influx and colloid osmotic cell swelling permits unabated lysosome translocation in exposed cells. The results indicate that the efforts used herein to preclude Ca2+ influx and colloid osmotic swelling following nsPEF exposure did not prevent attenuation of lysosome translocation. Intracellular lysosome movement is inhibited by nsPEF exposure(s) in the presence of PEG 300-containing solution or by 20 pulses of nsPEF in the presence of extracellular calcium. The only cases with no significant decreases in lysosome movement are the sham and exposure to a single nsPEF in Ca2+-free solution.