Vesicle System Research Articles

Extracellular Vesicles Tropism: A Comparative Study between Passive Innate Tropism and the Active Engineered Targeting Capability of Lymphocyte-Derived EVs.

Cellular communications take place thanks to a well-connected network of chemical–physical signals, biomolecules, growth factors, and vesicular messengers that travel inside or between cells. A deep knowledge of the extracellular vesicle (EV) system allows for a better understanding of the whole series of phenomena responsible for cell proliferation and death. To this purpose, here, a thorough immuno-phenotypic characterization of B-cell EV membranes is presented. Furthermore, the cellular membrane of B lymphocytes, Burkitt lymphoma, and human myeloid leukemic cells were characterized through cytofluorimetry assays and fluorescent microscopy analysis. Through cytotoxicity and internalization tests, the tropism of B lymphocyte-derived EVs was investigated toward the parental cell line and two different cancer cell lines. In this study, an innate capability of passive targeting of the native EVs was distinguished from the active targeting capability of monoclonal antibody-engineered EVs, able to selectively drive the vesicles, enhancing their internalization into the target cancer cells. In particular, the specific targeting ability of anti-CD20 engineered EVs towards Daudi cells, highly expressing CD20 marker on their cell membrane, was proved, while almost no internalization events were observed in HL60 cells, since they did not express an appreciable amount of the CD20 marker on their plasma membranes.

Hybrid Vesicles Based on Autologous Tumor Cell Membrane and Bacterial Outer Membrane To Enhance Innate Immune Response and Personalized Tumor Immunotherapy.

Tumor heterogeneity, often leading to metastasis, limits the development of tumor therapy. Personalized therapy is promising to address tumor heterogeneity. Here, a vesicle system was designed to enhance innate immune response and amplify personalized immunotherapy. Briefly, the bacterial outer membrane vesicle (OMV) was hybridized with the cell membrane originated from the tumor (mT) to form new functional vesicles (mTOMV). In vitro experiments revealed that the mTOMV strengthened the activation of innate immune cells and increased the specific lysis ability of T cells in homogeneous tumors. In vivo experiments showed that the mTOMV effectively accumulated in inguinal lymph nodes, then inhibited lung metastasis. Besides, the mTOMV evoked adaptive immune response in homologous tumor rather than the heterogeneous tumor, reversibly demonstrating the effects of personalized immunotherapy. The functions to inhibit tumor growth and metastasis accompanying good biocompatibility and simple preparation procedure of mTOMV provide their great potential for clinical applications.

Combination of multifunctional ursolic acid with kinase inhibitors for anti-cancer drug carrier vesicles

A sterically stabilized unilamellar nanocarrier vesicle (SSV) system containing dipalmitoylphosphatidylcholine, cholesterol, ursolic acid and PEGylated phospholipid has been developed by exploiting the structural advantages of ursolic acid: by spontaneously attaching to the lipid head groups, it induces curvature at the outer side of the bilayers, allowing the preparation of size-limited vesicles without extrusion. Ursolic acid (UA) also interacts with the PEG chains, supporting steric stabilization even when the amount of PEGylated phospholipid is reduced. Using fluorescence immunohistochemistry, vesicles containing ursolic acid (UA-SSVs) were found to accumulate in the tumor in 3 h on xenografted mouse, suggesting the potential use of these vesicles for passive tumor targeting.Further on, mono- and combination therapy with UA and six different kinase inhibitors (crizotinib, erlotinib, foretinib, gefitinib, refametinib, trametinib) was tested on seven cancer cell-lines. In most combinations synergism was observed, in the case of trametinib even at very low concentration (0.001 μM), which targets the MAPK pathway most often activated in human cancers. The coupled intercalation of UA and trametinib (2:1 molar ratio) into vesicles causes further structural advantageous molecular interactions, promoting the formation of small vesicles. The high drug:lipid molar ratio (~0.5) in the novel type of co-delivery vesicles enables their direct medical application, possibly also overcoming the multidrug resistance effect.

Solvent effect ofD2Oon the thermochromic sensitivity of polydiacetylene vesicle systems

AbstractThe solvent effect of D2O on the thermochromic sensitivity of a polydiacetylene (PDA) vesicle system was characterized and estimated numerically in this study. Three types of diacetylene compounds (10,12‐pentacosadiynoic acid,N‐[2‐(2‐hydroxyethoxy)ethyl]pentacosa‐10,12‐diynamide, andN‐(4‐aminophenyl)pentacosa‐10,12‐diynamide) were used to form the vesicle solution by sonication in H2O and D2O. This was followed by polymerization using UV irradiation to form a PDA vesicle system. The solvent effect of D2O on the physical properties of the PDA vesicles was estimated. The physical properties investigated herein were PDA vesicle size, critical vesicle concentration, and thermochromic change rate. The thermochromic change rate was measured using the relative degree of blue color (RBC), which was obtained from the UV spectrum data. The rate constants (kHand kD) of the thermochromic change were measured by plotting RBC against temperature. The solvent effect of D2O was estimated via the ratio kD/kH. Finally, the solvent effect of D2O on three physical properties of the PDA vesicles (vesicle size, critical vesicle concentration, and thermochromic change rate) was characterized numerically.

Nonionic surfactant vesicles as a novel drug delivery system for increasing the oral bioavailability of Ginsenoside Rb1

In the present study, a novel nonionic surfactant vesicles (NSVs) system consisting of cholesterol, Tween 80 and Span 80 was developed for the delivery of Ginsenoside Rb1 with an improved oral bioavailability. The prepared vesicles were hollow and spherically shaped with acceptable diameter (264.68 ± 4.17 nm), zeta potential (−11.58 ± 0.87 mV) and encapsulation efficiency (69.034 ± 0.045%). XRD analysis provided affirmed the encapsulation of Rb1 in the vesicles. The in vitro release profile of Rb1 from the vesicles in the two different media (double distilled water, pH 7.0, phosphate buffer solution, pH 7.4) showed statistical insignificant difference when compared with the free Ginsenoside Rb1. Notably, the pharmacokinetic analysis of optimized Ginsenoside Rb1-NSVs exhibited a higher Cmax (9.55 ± 0.5 μg/mL versus 6.22 ± 0.53 μg/mL) with 1.82-fold increase in relative oral bioavailability. Collectively, these findings revealed that the developed vesicles could be a novel alternative in improving the oral bioavailability of Ginsenoside Rb1 and extending its application in the clinical setting.

Relationship of color change to permeation of target compound in polydiacetylene vesicle system

AbstractPolydiacetylene (PDA) systems, which showed color changes due to the permeation of target molecules, were reported previously by our research group. To use the systems for controlled drug delivery systems, the relationship of the color change to the permeation time of the PDA vesicle must be characterized precisely. Therefore, this relationship was investigated and characterized in this study. Methotrexate (MTX) was used as the target compound and the detection of MTX is an important process in anticancer study. N‐(2‐aminoethyl)pentacosa‐10,12‐diynamide (AEPCDA) was used as the diacetylene surfactant. Dimethyldioctadecylammonium bromide (DOAB) was used as an assistant surfactant. The color change occurred when the mixed surfactant vesicles, with DOAB, were used. When a lower ratio of DOAB was added to the AEPCDA vesicle, the color change rate was slower than that when using the higher ratio of DOAB. The color change rate constants were estimated for several different ratios (AEPCDA:DOAB). Surfactants with different carbon numbers to DOAB were used as the assistant surfactants in this study. The results showed that the color change rate constant decreased with the increasing carbon number of the assistant surfactant. This means that the color change rate can be controlled by changing the assistant surfactant.

Synthesis of a near infrared-actuated phthalocyanine-lipid vesicle system for augmented photodynamic therapy

The efficacy of photodynamic therapy (PDT) is often limited by the poor bio-distributive properties of conventional photosensitizers and the local hypoxic microenvironment that characterises most solid tumours. Herein, a novel in situ oxygenic lipid formulation for photodynamic therapy (PDT) is reported. Such a hybrid was synthesized by adsorbing bimetallic nanozyme, MnO2@PtNPs (NPs = nanoparticles) onto graphene quantum dots (GQDs) – zinc (II) phthalocyanine conjugates, followed by liposomal encapsulation, affording it enhanced water solubility. The MnO2@PtNPs, which are is shown to possess excellent catalase-like properties surpassing that of MnO2 or PtNPs alone, serves to catalyze H2O2 to O2, while the zinc (II) phthalocyanine (1) serves to transform the formed oxygen to generate cytotoxic singlet oxygen immediately. We show that by combining each function of the respective building blocks, the as-synthesized 1-GQDs-MnO2@PtNPs-liposomes not only maintains the properties of oxygen supplementation through H2O2 catalysis but also displays cooperative properties for enhanced singlet oxygen production. Consequently, a remarkably improved PDT efficacy was observed for 1-GQDs-MnO2@PtNPs-liposomes in both normoxia and hypoxia. These results demonstrate the potential applicability of such nanozyme constituted 1-GQDs-MnO2@PtNPs-liposomes for achieving tumour treatment in hypoxic conditions by PDT.

Cholesterol-phospholipid interactions resist the detergent effect of bovine bile

Sphingomyelin (SM) and cholesterol complexation gives rise to detergent-resistant liquid-ordered domains. The persistence of these domains and subsequent mixed micelle formation was examined in the presence of bile under physiological digestive in vitro conditions for vesicles comprising either SM/cholesterol, porcine brain phosphatidylcholine (BPC)/cholesterol, or soy phosphatidylcholine (SPC)/cholesterol bilayers, the latter two systems having no liquid-ordered domains. Micellization of these digested phospholipid multilamellar vesicle systems was confirmed by transmission electron microscopy. Bovine bile was found to consist of large multilamellar sheets which subsumed phospholipid vesicles to form aggregated superstructures. Budding off from these superstructures were vesicle-to-micelle transition intermediates: unilamellar vesicles and cylindrical micelles. The presence of cholesterol (60/40 phospholipid/cholesterol mol/mol) delayed the initial rapid onset of digestion, but not for BPC and SPC vesicle systems. Acyl chain order/disorder before and after vesicle-to-micelle transition of all three phospholipid/cholesterol systems was examined using Raman spectroscopy. The addition of bovine bile to both PC/cholesterol vesicle systems reduced the overall ratio of acyl chain disorder to order. In SM/cholesterol vesicles with ≤ 20% mol cholesterol, only the lateral inter-acyl chain packing was reduced, whereas for SM/cholesterol vesicles with ≥ 30% mol cholesterol, a higher proportion of gauche-to-trans isomerization was apparent, demonstrating that SM/cholesterol complexes modify the acyl chain structure of micelles.

Galactose-Modified PH-Sensitive Niosomes for Controlled Release and Hepatocellular Carcinoma Target Delivery of Tanshinone IIA

Increasing the drug tumor-specific accumulation and controlling their release is considered one of the most effective ways to increase the efficacy of drugs. Here, we developed a vesicle system that can target hepatoma and release drugs rapidly within tumor cells. This non-ionic surfactant vesicle is biodegradable. Galactosylated stearate has been used to glycosylate the vesicles to achieve liver targeting; replacement of a portion (Chol:CHEMS = 1:1) of cholesterol by cholesteryl hemisuccinate (CHEMS) allows for a rapid release of drugs in an acidic environment. In vitro release experiments confirmed that galactose-modified pH-sensitive niosomes loaded with tanshinone IIA had excellent drug release performance in acid medium. In vitro experiments using ovarian cancer cells (A2780), colon cancer cells (HCT8), and hepatoma cell (Huh7, HepG2) confirmed that the preparation had specific targeting ability to hepatoma cells compared with free drugs, and this ability was dependent on the galactose content. Furthermore, the preparation also had a more substantial inhibitory effect on tumor cells, and subsequent apoptosis assays and cell cycle analyses further confirmed its enhanced anti-tumor effect. Results of pharmacokinetic experiments confirmed that the vesicle system could significantly extend the blood circulation time of tanshinone IIA, and the larger area under the curve indicated that the preparation had a better drug effect. Thus, the results of biodistribution experiments confirmed the in vivo liver targeting ability of this preparation. Niosomes designed in this manner are expected to be a safe and effective drug delivery system for liver cancer therapy.

Dermal and Transdermal Drug Delivery through Vesicles and Particles: Preparation and Applications.

Transdermal delivery over the past decade has become the field of interest for drug delivery due to its various advantages such as no first-pass metabolism, increased drug bioavailability, and easy administration. Different vesicle systems like ethosomes, liposomes, niosomes, and transferosomes along with particle systems like lipid nanoparticles, polymeric nanoparticles, carbon nanotubes, and fullerenes have been developed. These vesicles and particle systems have been developed using various easy and effective methods like cold injection method, rotary film evaporation, thin film hydration, high shear homogenization, solvent extraction method, and many more. These drug delivery systems are a very effective and feasible option for transdermal drug delivery and further developments can be made to increase their use. This article explains in detail the preparation methods and applications for these drug delivery systems.

It's Better To Be Lucky Than Smart.

Bacterial cytoplasmic membrane vesicles provide a unique experimental system for studying active transport. Vesicles are prepared by lysis of osmotically sensitized cells (i.e., protoplasts or spheroplasts) and comprise osmotically intact, unit-membrane-bound sacs that are approximately 0.5-1.0 μm in diameter and devoid of internal structure. Their metabolic activities are restricted to those provided by the enzymes of the membrane itself, and each vesicle is functional. The energy source for accumulation of a particular substrate can be determined by studying which compounds or experimental conditions drive solute accumulation, and metabolic conversion of the transported substrate or the energy source is minimal. These properties of the vesicle system constitute a considerable advantage over intact cells, as the system provides clear definition of the reactions involved in the transport process. This discussion is not intended as a general review but is concerned with respiration-dependent active transport in membrane vesicles from Escherichia coli. Emphasis is placed on experimental observations demonstrating that respiratory energy is converted primarily into work in the form of a solute concentration gradient that is driven by a proton electrochemical gradient, as postulated by the chemiosmotic theory of Peter Mitchell.

Photoresponsive chiral vesicles as a light harvesting matrix with tunable chiroptical properties.

A chiral vesicle system with photo-regulated chiroptical properties including Cotton effects and circularly polarized luminescence (CPL) was reported. Photoresponsive cyanostilbene was conjugated to the cholesteryl group, which provides chiral centers and lipophilic domain for the flexible vesicle membrane formation. The building block self-assembled into vesicles with exciton Cotton effects and CPL. The high dissymmetry g-factor of CPL at 10-2 order of magnitude was achieved. Upon UV light irradiation, Cotton effects were enhanced with an elevated g-factor by 3-fold, while the CPL dissymmetry factor showed a light irradiation resistance. A hydrophobic fluorescent dye (Nile Red) was loaded into vesicle membranes to allow energy transfer and chirality transfer to give red color CPL with retained high g-factor, while resistance to the UV light irradiation of vesicles was enhanced after loading the fluorescent dye. This study highlights the fabrication of the chiral vesicle system with noninvasively stimulus-responsive chiroptical properties, which may provide new thoughts for the fabrication of smart chiroptical materials in aqueous media.

Hybrid lipopolymer vesicle drug delivery and release systems.

Hybrid lipopolymer vesicles are membrane vesicles that can be self-assembled on both the micro- and nano-scale. On the nanoscale, they are potential novel smart materials for drug delivery systems that could combine the relative strengths of liposome and polymersome drug delivery systems without their respective weaknesses. However, little is known about their properties and how they could be tailored. Currently, most methods of investigation are limited to the microscale. Here we provide a brief review on hybrid vesicle systems with a specific focus on recent developments demonstrating that nanoscale hybrid vesicles have different properties from their macroscale counterparts.

Numerical approximations of the Navier–Stokes equation coupled with volume-conserved multi-phase-field vesicles system: Fully-decoupled, linear, unconditionally energy stable and second-order time-accurate numerical scheme

We consider the numerical approximation of the flow-coupled multi-phase-field elastic bending energy model of lipid vesicles. Based on the classical model with approximate volume conservation only, this paper first establishes a new model that can accurately conserve volume by adding some nonlocal terms to the model equation. Then, for the system coupled with the incompressible flow, we propose a novel numerical method to construct an effective scheme that is fully-decoupled, linear, unconditionally energy stable, and second-order time-accurate. The key idea to achieve the full decoupling nature is to introduce an ordinary differential equation to deal with the nonlinear coupling term that satisfies the so-called “zero-energy-contribution” property. Thus, in actual calculations, this scheme only needs to solve several independent linear equations with constant coefficients at each time step. We strictly prove the solvability and unconditional energy stability, and perform numerical simulations in 2D and 3D to verify the accuracy and stability of the scheme numerically.

Comparison of morphogenesis and anatomy between hairy roots and adventitious roots of Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.)

In this study, morphogenesis and anatomy of adventitious roots and hairy roots of Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) were compared. Adventitious roots were derived from four different samples (leaf, petiole, root and callus) in vitro cultured on medium SH supplemented with 5 mg/L IBA. Hairy roots were derived from callus infected with Agrobacterium rhizogenes strain ATCC 15834. The results showed that there were significant differences in morphogenesis and anatomy, the pathway of secondary roots formation, culture medium between adventitous roots and hairy roots. The hairy roots strongly grew and branched on the free-plant growth regulator medium. The secondary root of the hairy root was formed in two pathways: (1) The secondary root formation began at the vesicles system of main root; (2) The secondary root formation was independent of the vesicles system of main root; it kept developing in length and connected to the vesicles system of main root. On the other hand, growing adventitous roots only grew on the environment with exogenous auxin supplementation; also their branching ability were low. The secondary root formation of the adventitous root was started at the vesicles of the main roots and there was only one secondary root that was formed at an location of adventitous root. The results that obtained in this study will be the reference to identify two types of root.

Supramolecular assembly of ionic liquid induced by UO2 2+: a strategy for selective extraction-precipitation

Abstract In this work, a novel task specific ionic liquid (TSIL) [tributyl(hexyl)phosphonium]2[diglycolic acetate] ([P6,4,4,4]2[DGA]) was prepared and used to construct a vesicle system. The addition of UO2 2+, La3+ or Th4+ exhibited different effects on the system. It was found that small amount of UO2 2+ could induce large-sized aggregation of vesicles and make the precipitation happen, while La3+ and Th4+ did not have such capacity. The whole process was characterized by dynamic light scattering and freeze-fracture transmission electron microscopy. An extraction-precipitation strategy was then developed for the selective recovery of UO2 2+. Different factors were further studied to optimize the separation efficiency of the extraction-precipitation process.

Interaction of human serum albumin with diclofenac incorporated in catanionic vesicles

In this study, we have prepared a cationic SDS/CTAB vesicle membrane and a non-steroidal anti-inflammatory (NSAID) drug, diclofenac sodium was incorporated in it. Further, the interaction of human serum albumin with diclofenac and diclofenac incorporated cationic vesicle was studied by different techniques such as, scanning electron microscopy (SEM), dynamic light scattering (DLS), FTIR, UV–visible and fluorescence spectroscopy. The dynamic light scattering interprets that the particle size of the HSA-vesicle system is greater as related to their pure vesicle system. The CD data clearly suggests that cationic vesicles do not have any denaturising effect on HSA (human serum albumin). The fluorescence results show the strong quenching with the formation of complex between HSA and diclofenac vesicle with static quenching. The binding constant, Kb of HSA with DIC incorporated catanionic vesicle is less than the binding constant of HSA-DIC interaction, this shows the slow release of drug from the vesicle. The UV–visible results suggest that DIC in presence of vesicles connects with HSA and shows no apparent effect on the micro-environment of the fluorophore residues of HSA.

A tandem ionic liquid‐based dispersive microextraction method using in‐syringe air‐assisted vesicle system for rapid determination of lead and cadmium in artificial sweat extract of facial cosmetic products

In the present study an innovative tandem ionic liquid‐based dispersive microextraction method using an in‐syringe air‐assisted vesicle system was developed to determine the ultra‐trace levels of lead (PbII) and cadmium (CdII) ions in synthetic sweat extract of branded and nonbranded facial cosmetic products. This method is based on injecting 2‐amino‐3‐sulfhydrylpropanoic acid (l‐cysteine) (as an eco‐friendly chelating agent), hexafluorophosphate ion [PF6−] (as an ion pair agent) and 1‐hexyl‐3‐methylimidazolium hexafluorophosphate [HMIM] [PF6] (as an acceptor phase) into the synthetic sweat extract of facial cosmetic products (branded and nonbranded). The acceleration of the dispersion process was carried out by rapid pressure in the syringe through the back‐and‐forth movement of plunger. The sediment phase was removed following centrifugation, and then hydrophobic complexes of analyte were back‐extracted into HNO3 and finally injected into a flame atomic absorption spectrometer. Several factors were systematically optimized. The validity of the methodology was tested by analyzing spiked known standards of both metals in a real sample. The proposed method was applied to the artificial sweat extracts of face makeup products, indicating how much toxic metals from different cosmetics are directly absorbed into skin.

Biophysical analysis of lipidic nanoparticles.

Biological nanoparticles include liposomes, extracellular vesicle and lipid-based discoidal systems. When studying such particles, there are several key parameters of interest, including particle size and concentration. Measuring these characteristics can be of particular importance in the research laboratory or when producing such particles as biotherapeutics. This article briefly describes the major types of lipid-containing nanoparticles and the techniques that can be used to study them. Such methodologies include electron microscopy, atomic force microscopy, dynamic light scattering, nanoparticle tracking analysis, flow cytometry, tunable resistive pulse sensing and microfluidic resistive pulse sensing. Whilst no technique is perfect for the analysis of all nanoparticles, this article provides advantages and disadvantages of each, highlighting the latest developments in the field. Finally, we demonstrate the use of microfluidic resistive pulse sensing for the analysis of biological nanoparticles.

Chromatic response of cationic polydiacetylene vesicles induced by permeation of target compound

AbstractA polydiacetylene vesicle was formed by sonication and UV irradiation of the diacetylene DPAI‐bis‐PCDA, which has quaternary ammonium head group. A color‐changeable detection system during permeation of the target compound from inside to outside the vesicle was prepared using this vesicle. A mixed vesicle system with DPAI‐bis‐PCDA and dioctadecyldimethylammonium chloride (DODMAC) was used in this study. DODMAC was necessary to exhibit sufficient color change. Methotrexate and neomycin were used as target compounds, and the optimum ratio of DPAI‐bis‐PCDA to DODMAC for sufficient color change was determined. When MTX was used as the target compound, 6:4 was the optimum ratio, whereas it was 7:3 for neomycin.