Unveiling microwave and Roasting-Steam heating mechanisms in regulating fat changes in pork using cell membrane simulation

Fat reduction due to heating or cooking is an important issue in a healthy diet. In the current study, pork subcutaneous back fat was treated via microwave heating (MH) within 10-90 s and roasting - steam heating (RSH) within 2-30 min and their dynamic changes of individual adipocytes were explored by using vesicles as a bio-membrane model. The result showed that MH and RSH significantly increased fat loss (P < 0.05), with the maximum losses being 74.1 % and 65.6 %, respectively. The mechanical strength of connective tissue decreased and then increased slightly. The microstructure demonstrated that MH and RSH treatments facilitated a large outflow of fat, showing that the particle size of the vesicle and individual adipocytes increased and then decreased. It is thus feasible to study the dynamic changes of individual adipocytes in regulating fat reduction using cell membrane simulation.

Comparative analysis of whole cell-derived vesicular delivery systems for photodynamic therapy of extrahepatic cholangiocarcinoma

This first-in-its-class proof-of-concept study explored the use of bionanovesicles for the delivery of photosensitizer into cultured cholangiocarcinoma cells and subsequent treatment by photodynamic therapy (PDT). Two types of bionanovesicles were prepared: cellular vesicles (CVs) were fabricated by sonication-mediated nanosizing of cholangiocarcinoma (TFK-1) cells, whereas cell membrane vesicles (CMVs) were produced by TFK-1 cell and organelle membrane isolation and subsequent nanovesicularization by sonication. The bionanovesicles were loaded with zinc phthalocyanine (ZnPC). The CVs and CMVs were characterized (size, polydispersity index, zeta potential, stability, ZnPC encapsulation efficiency, spectral properties) and assayed for tumor (TFK-1) cell association and uptake (flow cytometry, confocal microscopy), intracellular ZnPC distribution (confocal microscopy), dark toxicity (MTS assay), and PDT efficacy (MTS assay). The mean ± SD diameter, polydispersity index, and zeta potential were 134 ± 1 nm, -16.1 ± 0.9, and 0.220 ± 0.013, respectively, for CVs and 172 ± 3 nm, -16.4 ± 1.1, and 0.167 ± 0.022, respectively, for CMVs. Cold storage for 1 wk and incorporation of ZnPC increased bionanovesicular diameter slightly but size remained within the recommended range for in vivo application (136-220 nm). ZnPC was incorporated into CVs and CMVs at an optimal photosensitizer:lipid molar ratio of 0.006 and 0.01, respectively. Both bionanovesicles were avidly taken up by TFK-1 cells, resulting in homogenous intracellular ZnPC dispersion. Photosensitization of TFK-1 cells did not cause dark toxicity, while illumination at 671 nm (35.3 J/cm2) produced LC50 values of 1.11 μM (CVs) and 0.51 μM (CMVs) at 24 h post-PDT, which is superior to most LC50 values generated in tumor cells photosensitized with liposomal ZnPC. In conclusion, CVs and CMVs constitute a potent photosensitizer platform with no inherent cytotoxicity and high PDT efficacy in vitro.

Impact of formulation parameters on self-assembled liposomes (LeciPlex® III): A detailed investigation

The present study investigated the feasibility of fabricating self-assembled liposomes, LeciPlex®, a phospholipid-based vesicular nanocarrier using cationic, anionic, and nonionic stabilizers. The phospholipid investigated was soy phosphatidylcholine and the nano-precipitation method based on solvent diffusion was applied as the fabrication technique of liposomes in this study. The effects of various formulation variables, such as lipid and stabilizer concentration, total solid concentration, and solvent type on the self-assembly of vesicles were studied for physical characterization including particle size analysis, differential scanning calorimetry, viscosity, optical transmittance, transmission electron microscopy, and small angle neutron scattering. All three LeciPlex® systems exhibited a direct relationship between particle size and phospholipid concentration. The two categoric variables, solvent, and stabilizer used to prepare LeciPlex® demonstrated a significant effect on particle size for all three LeciPlex® systems. Small angle neutron scattering, and optical transmittance confirmed the formation of micellar systems at a phospholipid: stabilizer ratio of 1:2 and vesicular systems at a ratio of 2:1 for the systems stabilized with anionic and nonionic surfactants. In contrast to this, the LeciPlex® formed with the cationic stabilizer Dioctadecyldimethylammonium bromide (DODAB), formed vesicles at both ratios. From these investigations, it was clear that the formulation space for LeciPlex® was diversified by the addition of cationic, anionic, and non-ionic stabilizers.

Role of Shape in Particle-Lipid Membrane Interactions: From Surfing to Full Engulfment

Understanding and manipulating the interactions between foreign bodies and cell membranes during endo- and phagocytosis is of paramount importance, not only for the fate of living cells but also for numerous biomedical applications. This study aims to elucidate the role of variables such as anisotropic particle shape, curvature, orientation, membrane tension, and adhesive strength in this essential process using a minimal experimental biomimetic system comprising giant unilamellar vesicles and rod-like particles with different curvatures and aspect ratios. We find that the particle wrapping process is dictated by the balance between the elastic free energy penalty and adhesion free energy gain, leading to two distinct engulfment pathways, tip-first and side-first, emphasizing the significance of the particle orientation in determining the pathway. Moreover, our experimental results are consistent with theoretical predictions in a state diagram, showcasing how to control the wrapping pathway from surfing to partial to complete wrapping by the interplay between membrane tension and adhesive strength. At moderate particle concentrations, we observed the formation of rod clusters, which exhibited cooperative and sequential wrapping. Our study contributes to a comprehensive understanding of the mechanistic intricacies of endocytosis by highlighting how the interplay between the anisotropic particle shape, curvature, orientation, membrane tension, and adhesive strength can influence the engulfment pathway.

Recent advances of droplet-based microfluidics for engineering artificial cells

Artificial cells, synthetic cells, or minimal cells are microengineered cell-like structures that mimic the biological functions of cells. Artificial cells are typically biological or polymeric membranes where biologically active components, including proteins, genes, and enzymes, are encapsulated. The goal of engineering artificial cells is to build a living cell with the least amount of parts and complexity. Artificial cells hold great potential for several applications, including membrane protein interactions, gene expression, biomaterials, and drug development. It is critical to generate robust, stable artificial cells using high throughput, easy-to-control, and flexible techniques. Recently, droplet-based microfluidic techniques have shown great potential for the synthesis of vesicles and artificial cells. Here, we summarized the recent advances in droplet-based microfluidic techniques for the fabrication of vesicles and artificial cells. We first reviewed the different types of droplet-based microfluidic devices, including flow-focusing, T-junction, and coflowing. Next, we discussed the formation of multi-compartmental vesicles and artificial cells based on droplet-based microfluidics. The applications of artificial cells for studying gene expression dynamics, artificial cell-cell communications, and mechanobiology are highlighted and discussed. Finally, the current challenges and future outlook of droplet-based microfluidic methods for engineering artificial cells are discussed. This review will provide insights into scientific research in synthetic biology, microfluidic devices, membrane interactions, and mechanobiology.

Poly (vinyl alcohol)-gelatin-sericin copolymerized film fortified with vesicle-entrapped demethoxycurcumin/bisdemethoxycurcumin for improved stability, antibacterial, anti-inflammatory, and skin tissue regeneration

Vesicle delivery carriers, used to stabilize hydrophobic drugs, are characterized by the propensity to aggregate, and fuse, limiting its applications. Fortifying vesicle-entrapped drugs within a biodegradable polymeric film constitutes a promising solution. In this study, biodegradable poly (vinyl alcohol) copolymerized with gelatin-sericin film and integrated alongside vesicle-entrapped demethoxycurcumin (DMC) or bisdemethoxycurcumin (BDMC) was developed, extensively characterized for improve efficacy, and compared. Vesicle-entrapped DMC or BDMC was spherical in shape with no changes in size, zeta-potential, and morphology after storing at 4 °C for 30 days. Antibacterial activity of vesicle-entrapped DMC formulations against Acinetobacter baumannii and Staphylococcus epidermidis was more effective than that of its free form. DMC and BDMC demonstrated dose dependent reduction in lipopolysaccharides (LPS)-induced nitric oxide (NO) levels either in free or in entrapped form. Moreover, vesicle-entrapped DMC/BDMC suppressed NO production at lower concentrations, compared with that of their free form and significantly improved the viability of RAW264.7 and HaCaT cells. Furthermore, functionalized film with vesicle-entrapped DMC/BDMC demonstrated excellent radical scavenging, biocompatibility, and cell migration efficacy. Thus, incorporating vesicle, entrapped DMC/BDMC within biodegradable polymeric film may comprised a promising strategy for improving stability, wound healing, and inflammation attenuation efficacy.

Hybrid Vesicles Enable Mechano-Responsive Hydrogel Degradation

Stimuli-responsive hydrogels are intriguing biomimetic materials. Previous efforts to develop mechano-responsive hydrogels have mostly relied on chemical modifications of the hydrogel structures. Here, we present a simple, generalizable strategy that confers mechano-responsive behavior on hydrogels. Our approach involves embedding hybrid vesicles, composed of phospholipids and amphiphilic block copolymers, within the hydrogel matrix to act as signal transducers. Under mechanical stress, these vesicles undergo deformation and rupture, releasing encapsulated compounds that can control the hydrogel network. To demonstrate this concept, we embedded vesicles containing ethylene glycol tetraacetic acid (EGTA), a calcium chelator, into a calcium-crosslinked alginate hydrogel. When compressed, the released EGTA sequesters calcium ions and degrades the hydrogel. This study provides a novel method for engineering mechano-responsive hydrogels that may be useful in various biomedical applications.

Relaxing Wrinkles in Jammed Interfacial Assemblies

Dynamic covalent bonding has emerged as a mean by which stresses in a network can be relaxed. Here, the strength of the bonding of ligands to nanoparticles at the interface between two immiscible liquids affect the same results in jammed assemblies of nanoparticle surfactants. Beyond a critical degree of overcrowding induced by the compression of jammed interfacial assemblies, the bonding of ligands to nanoparticles (NPs) can be broken, resulting in a desorption of the NPs from the interface. This reduces the areal density of nanoparticle surfactants at the interface, allowing the assemblies to relax, not to a fluid state but rather another jammed state. The relaxation of the wrinkles caused by the compression reflects the tendency of these assemblies to eliminate areas of high curvature, favoring a more planar geometry. This enabled the generation of giant vesicular and multivesicular structures from these assemblies.

Migrasome, a novel organelle, differs from exosomes

Migrasomes, a newly discovered organelle produced by migrating cells, are vesicles with membranous structure that form on the tips and intersections of retraction fibers (RFs). These structures are released into the extracellular environment or taken up by surrounding cells, mediating the release of cytoplasmic contents and intercellular communication. Retractosomes, a new type of small extracellular vesicles generated from broken-off RFs, are closely related to migrasomes in their physical location and origin, but were defined later. Despite their widespread existence in cells and biological organisms, little is known about the regulatory mechanisms underlying their formation and potential function. In this review, we provide an overview of the discovery, biogenesis, distribution, and functions of migrasomes and retractosomes, as well as their differences from exosomes.

Kingella kingae RtxA toxin interacts with sialylated gangliosides

The membrane-damaging RTX family cytotoxin RtxA is a key virulence factor of the emerging pediatric pathogen Kingella kingae, but little is known about the mechanism of RtxA binding to host cells. While we have previously shown that RtxA binds cell surface glycoproteins, here we demonstrate that the toxin also binds different types of gangliosides. The recognition of gangliosides by RtxA depended on sialic acid side groups of ganglioside glycans. Moreover, binding of RtxA to epithelial cells was significantly decreased in the presence of free sialylated gangliosides, which inhibited cytotoxic activity of the toxin. These results suggest that RtxA utilizes sialylated gangliosides as ubiquitous cell membrane receptor molecules on host cells to exert its cytotoxic action and support K. kingae infection.

Extracellular vesicles as a strategy for cadmium secretion in bacteria SH225

Cadmium (Cd), as one of the most carcinogenic substances, poses a great threat to human health. With the development of microbial remediation technology, the necessity for urgent research into the mechanism of Cd toxicity to bacteria has arisen. In this study, a highly Cd-tolerant strain (up to 225 mg/L) was isolated and purified from Cd-contaminated soil, which was identified by 16S rRNA as a strain of Stenotrophomonas sp., thus manually designated as SH225. By testing OD₆₀₀ of the strain, we indicated that Cd concentrations below 100 mg/L had no discernible impact on the biomass of SH225. When the Cd concentration was over 100 mg/L, the cell growth was significantly inhibited, while the number of extracellular vesicles (EVs) was greatly elevated. After extraction, cell-secreted EVs were confirmed to contain large amounts of Cd cations, highlighting the crucial function of EVs in the Cd detoxification of SH225. Meanwhile, the TCA cycle was vastly enhanced, suggesting that the cells provided adequate energy supply for EVs transport. Thus, these findings emphasized the crucial role played by vesicles and TCA cycle in Cd detoxification.

Encapsulation and release of hydrocortisone from proliposomes govern vaginal delivery

Topical preparations of hydrocortisone can be used for the anti-inflammatory treatment of the female genital area. Although the drug is a low-strength corticosteroid, systemic absorption and distribution of the drug are the most common safety risks associated with this therapy. In the current investigation, we elucidate the physicochemical properties of lipid-based drug carrier systems that govern the local bioavailability of hydrocortisone for intravaginal administration. For this purpose, we compared various proliposome formulations with a commercial cream. Depending on the availability of physiological acceptors, encapsulation and drug release from the lipid phase were found to be the most important drivers of drug bioavailability. The high permeability of hydrocortisone leads to rapid transport of the drug across the mucosal cell layer as indicated by experiments using HEC-1-A and CaSki cell monolayer models. Under sink conditions, differences in the release from the liposomes as determined in the Dispersion Releaser were almost negligible. However, under non-sink conditions, the drug release plateaued at levels corresponding to the encapsulation efficiency. After redispersion, all liposomal formulations performed better than the commercial drug product indicating that the encapsulation into the lipid phase is the main driver sustaining the release.

Effects of Biliary Phospholipids on Cholesterol Crystallization and Growth in Gallstone Formation

The prevalence of cholesterol gallstone disease is increasing, primarily due to the global epidemic of obesity associated with insulin resistance, and this trend leads to a considerable healthcare, financial, and social burden worldwide. Although phospholipids play an essential role in maintaining cholesterol solubility in bile through both mixed micelles and vesicles, little attention has been paid to the impact of biliary phospholipids on the pathogenesis of cholesterol gallstone formation. A reduction or deficiency of biliary phospholipids results in a distinctly abnormal metastable physical-chemical state of bile predisposing to supersaturation with cholesterol. Changes in biliary phospholipid concentrations influence cholesterol crystallization by yielding both liquid crystalline and "anhydrous" crystalline metastable intermediates, evolving into classical parallelogram-shaped cholesterol monohydrate crystals in supersaturated bile. As a result, five distinct crystallization pathways, A-E, have been defined, mainly based on the prime habits of liquid and solid crystals in the physiological or pathophysiological cholesterol saturation of gallbladder and hepatic bile. This review concisely summarizes the chemical structures and physical-chemical properties of biliary phospholipids and their physiological functions in bile formation and cholesterol solubility in bile, as well as comprehensively discusses the latest advances in the role of biliary phospholipids in cholesterol crystallization and growth in gallstone formation, largely based on the findings from clinical and animal studies and in vitro experiments. The insights gleaned from uncovering the cholelithogenic mechanisms are expected to form a fundamental framework for investigating the hitherto elusive events in the earliest stage of cholesterol nucleation and crystallization. This may help to identify better measures for early diagnosis and prevention in susceptible subjects and effective treatment of patients with gallstones.

Preparation of Giant Vesicles with Mixed Single-Tailed and Double-Tailed Lipids

Giant vesicles are model membrane systems that can be characterized with microscopy. Whereas most giant synthetic vesicles are created with a single phospholipid species, vesicles with mixed membrane compositions, including single-tailed and double-tailed lipids, serve as more accurate models of biological membranes and also have applications in the origins of life and drug delivery fields. Here we describe several approaches that can be used to create giant vesicles with mixed lipid compositions.

Scalable Liposome Synthesis by High Aspect Ratio Microfluidic Flow Focusing

Microfluidic flow focusing provides an efficient approach to the generation of nanoscale lipid vesicles of tunable size and low size variance. Scalable nanoliposome synthesis over a wide range of production rates can be readily achieved using a high aspect ratio flow focusing device fabricated by widely available additive manufacturing methods. Here we detail methods for the manufacture and operation of a 3D-printed microfluidic flow focusing technology enabling the synthesis of liposomes with modal diameters ranging from ca. 50-200 nm at production rates up to several hundred milligrams lipid per hour.

Visualization and Characterization of Liposomes by Atomic Force Microscopy

Atomic force microscopy is a high-resolution and nonoptical technique used to visualize and characterize biological samples and surfaces. In pharmaceutical research and development (R&D) and quality control (QC), drug delivery systems, like liposomes with sizes in a nanometer range, are preferred samples to be studied through atomic force microscopy. The instrument can determine the sample's topography (e.g., height), morphology, and material properties (e.g., hardness, adhesiveness). Various measuring modes, e.g., intermittent contact (AC mode), can generate height (measured), lock-in amplitude, and lock-in phase data, revealing interesting details about the drug delivery system.In this study, empty and drug-loaded liposomes with various lipid compositions and sizes (50-800 nm) were visualized and characterized with state-of-the-art atomic force microscope (AFM). The main focus here was the preparation methods of the samples, instrumental settings, and pitfalls that can occur during the whole imaging process. Moreover, troubleshooting and postdata processing are essential for a high-quality outcome.

Unimer Exchange Is not Necessary for Morphological Transitions in Polymerization-Induced Self-Assembly

Polymerization-induced self-assembly (PISA) has established itself as a powerful and straightforward method to produce polymeric nano-objects of various morphologies in (aqueous) solution. Generally, spheres are formed in the early stages of polymerization that may evolve to higher order morphologies (worms or vesicles), as the solvophobic block grows during polymerization. Hitherto, the mechanisms involved in these morphological transitions during PISA are still not well understood. Combining a systematic study of a representative PISA system with rheological measurements, we demonstrate that-unexpectedly-unimer exchange is not necessary to form higher order morphologies during radical RAFT-mediated PISA. Instead, in the investigated aqueous PISA, the monomer present in the polymerization medium is responsible for the morphological transitions, even though it slows down unimer exchange.

High-Precision Mapping of Membrane Proteins on Synaptic Vesicles using Spectrally Encoded Super-Resolution Imaging

The spatial resolution of single-molecule localization microscopy is limited by the photon number of a single switching event because of the difficulty of correlating switching events dispersed in time. Here we overcome this limitation by developing a new class of photoswitching semiconducting polymer dots (Pdots) with structured and highly dispersed single-particle spectra. We imaged the Pdots at the first and the second vibronic emission peaks and used the ratio of peak intensities as a spectral coding. By correlating switching events using the spectral coding and performing 4-9 frame binning, we achieved a 2-3 fold experimental resolution improvement versus conventional superresolution imaging. We applied this method to count and map SV2 and proton ATPase proteins on synaptic vesicles (SVs). The results reveal that these proteins are trafficked and organized with high precision, showing unprecedented level of detail about the composition and structure of SVs.

Spatiotemporal Propagation of a Minimal Catalytic RNA Network in GUV Protocells by Temperature Cycling and Phase Separation

Compartmentalization is key to many cellular processes and a critical bottleneck of any minimal life approach. In cells, a complex chemistry is responsible for bringing together or separating biomolecules at the right place at the right time. Lipids, nucleic acids and proteins self-organize, thereby creating boundaries, interfaces and specialized microenvironments. Exploiting reversible RNA-based liquid-liquid phase separation (LLPS) inside giant unilamellar vesicles (GUVs), we present an efficient system capable of propagating an RNA-based enzymatic reaction across a population of GUVs upon freezing-thawing (FT) temperature cycles. We report that compartmentalization in the condensed RNA-rich phase can accelerate such an enzymatic reaction. In the decondensed state, RNA substrates become homogeneously dispersed, enabling content exchange between vesicles during freeze-thawing. This work explores how a minimal reversible phase separation system in lipid vesicles could help to implement spatiotemporal control in cyclic processes, as required for minimal cells.

A Mini-review Based on Multivesicular Liposomes: Composition, Design, Preparation, Characteristics, and Therapeutic Importance as DEPOFOAM® Technology

Vesicular delivery systems are a kind of drug delivery system that is gaining popularity due to its sustained release nature. This article was designed to understand the characteristics of a drug carrier called multivesicular liposomes, which have the potential to be the future of sustained-release drug delivery systems. Multivesicular liposomes have a honeycomb-like structure made up of non-concentric aqueous polyhedral compartments separated by continuous lipid membranes. Because of their unusual structure, they can encapsulate both hydrophilic and lipophilic pharmaceuticals and release them in a prolonged and controlled manner. They also have high encapsulation efficiency, bioavailability, biocompatibility, and stability, and are biodegradable by nature, making them suitable for treating chronic disorders. Encapsulating drugs into multivesicular liposomes is called DepoFoam® technology, which has the capability to release them in a timely manner, lowering the drug administration frequency. As a result, the FDA has approved several various approaches for this technology to treat chronic conditions. Multivesicular liposomes in the form of DepoFoam® technology hold a promising future as a novel drug delivery system. Much research needs to be done to extend their use across various aspects of the therapeutic field.

GEARBOCS: An Adeno Associated Virus Tool for In Vivo Gene Editing in Astrocytes

In the mammalian central nervous system (CNS), astrocytes are indispensable for brain development, function, and health. However, non-invasive tools to study astrocyte biology and function in vivo have been limited to genetically modified mice. CRISPR/Cas9-based genome engineering enables rapid and precise gene manipulations in the CNS. Here, we developed a non-invasive astrocyte-specific method utilizing a single AAV vector, GEARBOCS (Gene Editing in AstRocytes Based On CRISPR/Cas9 System). We verified GEARBOCS' specificity to mouse cortical astrocytes and demonstrated its utility for three types of gene manipulations: knockout (KO); tagging (TagIN); and reporter gene knock-in (Gene-TRAP) strategies. We deployed GEARBOCS to determine whether cortical astrocytes express Vamp2 protein. The presence of Vamp2-positive vesicles in cultured astrocytes is well-established, however, Vamp2 protein expression in astrocytes in vivo has proven difficult to ascertain due to its overwhelming abundance in neurons. Using GEARBOCS, we delineated the in vivo astrocytic Vamp2 expression and found that it is required for maintaining excitatory and inhibitory synapse numbers in the visual cortex. GEARBOCS strategy provides fast and efficient means to study astrocyte biology in vivo.

Vesicle Collision Protocols for the Study of Quantum Size and Exocytotic Fraction Released

We review the methods of vesicle impact electrochemical cytometry, intracellular impact electrochemical cytometry, and single cell amperometry and their application to measuring the storage of neurotransmitters in cellular vesicles. We provide protocols to measure vesicle content, the release of catecholamines, and from there the fraction of transmitter released in each exocytosis event. The focus here has been a combination of methods to evaluate factors related to neuronal function at the cellular level and implications in, for example, cognition.

Suprasomes Based on Host-Guest Molecular Recognition: An Excellent Alternative to Liposomes in Cancer Theranostics

Liposomes and polymersomes, typical vesicular drug delivery systems (DDSs), have faced some limitations in cancer theranostics. Suprasomes, supramolecular vesicles assembled from amphiphiles linked by noncovalent interactions, show potential as new generation of vesicular DDSs. We construct suprasomes based on host-guest recognition, by which the desired functions can be integrated into carriers without tedious synthesis. Photothermally active host-guest complex is formed between a functional guest and pillar[5]arene, which further self-assembles into hollow suprasomes. A supramolecular nanomedicine is developed by encapsulating cisplatin in the suprasomes. The obtained cisplatin@Suprasomes achieve excellent anticancer efficacy and anti-metastasis combining chemotherapy and photothermal therapy, which ablate the tumors without relapse and metastasis. This work demonstrates the facile functionalization of suprasomes, holding promise as alternatives to liposomes and polymersomes.

An Electron Tomographic Analysis of Giantin-Deficient Golgi Proposes a New Function of the Golgin Protein Family

The Golgi apparatus is an organelle that mediates modifications, sorting, and transport of proteins and lipids. Golgins are a group of proteins with coiled-coil structures that localize to the Golgi and are thought to function as tethers to facilitate the docking of vesicles, Rab GTPases, and cytoskeleton components to the Golgi stack. Giantin is the longest golgin and has been thought to function as a tether for COPI vesicles along with other golgins, such as p115 and GM130. Contrary to our expectation that the loss of the tether will result in an increase in untethered COPI vesicles in the cytoplasm, our electron microscopy observations showed that the fenestrae normally present in Golgi cisternae were reduced upon Giantin knockdown. We also found that this structural change is accompanied by altered secretion of cargo proteins and cell surface glycosylation. These results indicate that there exists a correlation between Golgi structural changes caused by the loss of Giantin and Golgi function. Here, we describe electron tomography methods for the detection of structural changes in the Golgi.

The role of the transmembrane domain of silicanin-1: Reconstitution of the full-length protein in artificial membranes

Biosilica formation in diatoms is a membrane-confined process that occurs in so-called silica deposition vesicles (SDVs). As SDVs have as yet not been successfully isolated, the impact of the SDV membrane on silica morphogenesis is not well understood. However, recently the first SDV transmembrane protein, silicanin-1 (Sin1) has been identified that appears to be involved in biosilica formation. In this study, we recombinantly expressed and isolated full-length Sin1 from E. coli and investigated its reconstitution behavior in artificial membranes. A reconstitution efficiency in vesicles of up to 80% was achieved by a co-micellization method. By using a chymotrypsin digest, the orientation of Sin1 in unilamellar vesicles was analyzed indicating a positioning of the large N-terminal domain to the outside of the vesicles. These proteoliposomes were capable of precipitating silica in the presence of long-chain polyamines. Supported lipid bilayers were produced by proteoliposome spreading on lipid monolayers to form continuous lipid bilayers with Sin1 confined to the membrane. Successful Sin1 reconstitution into these planar membranes was shown by means of immunostaining with purified primary anti-Sin1 and secondary fluorescent antibodies. The established planar model membrane system, amenable for surface sensitive and microscopy techniques, will pave the way to investigate SDV-membrane interactions with other SDV associated biomolecules and its role in silica biogenesis.

Amphiphilic Ionic Liquids Capable to Formulate Organized Systems in an Aqueous Solution, Designed by a Combination of Traditional Surfactants and Commercial Drugs

The present review describes the state of the art in the conversion of pharmaceutically active ingredients (API) in amphiphilic Ionic Liquids (ILs) as alternative drug delivery systems. In particular, we focus our attention on the compounds generated by ionic exchange and without original counterions which generate different systems in comparison with the simple mixtures. In water, these new amphiphiles show similar or even better properties as surfactants in comparison with their precursors. Cations such as 1-alkyl-3-methyl-imidazolium and anions such as dioctyl sulfosuccinate or sodium dodecyl sulfate appear as the amphiphilic components most studied. In conclusion, this work shows interesting information on several promissory compounds and they appear as an interesting challenge to extend the application of ILs in the medical field.

Designer peptides as versatile building blocks for functional materials

Peptides and pseudopeptides show distinct self-assembled nanostructures such as fibers, nanotubes, vesicles, micelles, toroids, helices and rods. The formation of such molecular communities through the collective behavior of molecules is not fully understood at a molecular level. All these self-assembled nanostructured materials have a wide range of applications such as drug delivery, gene delivery, biosensing, bioimaging, catalysis, tissue engineering, nano-electronics and sensing. Self-assembly is one of the most efficient and a simple strategy to generate complex functional materials. Owing to its significance, the last few decades witnessed a remarkable advancement in the field of self-assembling peptides with a plethora of new designer synthetic systems being discovered. These systems range from amphiphilic, cyclic, linear and polymeric peptides. This article presents only selected examples of such self-assembling peptides and pseudopeptides.

Glutathione Depletion-Induced Activation of Dimersomes for Potentiating the Ferroptosis and Immunotherapy of "Cold" Tumor

The abundant glutathione (GSH) in "cold" tumors weakens ferroptosis therapy and the immune response. Inspired by lipids, we fabricated cinnamaldehyde dimers (CDC) into lipid-like materials to form dimersomes capable of depleting GSH and delivering therapeutics to potentiate the ferroptosis and immunotherapy of breast cancer. The dimersomes exhibited superior storage stability for over one year. After reaching the tumor, they quickly underwent breakage in the cytosol owing to the conjugation of hydrophilic GSH on CDC by Michael addition, which not only triggered the drug release and fluorescence switch "ON", but also led to the depletion of intracellular GSH. Ferroptosis was significantly enhanced after combination with sorafenib (SRF) and elicited a robust immune response in vivo by promoting the maturation of dendritic cells and the priming of CD8⁺ T cells. As a result, the CDC@SRF dimersomes cured breast cancer in all the mice after four doses of administration.

Probing the Link between Pancratistatin and Mitochondrial Apoptosis through Changes in the Membrane Dynamics on the Nanoscale

Pancratistatin (PST) is a natural antiviral alkaloid that has demonstrated specificity toward cancerous cells and explicitly targets the mitochondria. PST initiates apoptosis while leaving healthy, noncancerous cells unscathed. However, the manner by which PST induces apoptosis remains elusive and impedes the advancement of PST as a natural anticancer therapeutic agent. Herein, we use neutron spin-echo (NSE) spectroscopy, molecular dynamics (MD) simulations, and supporting small angle scattering techniques to study PST's effect on membrane dynamics using biologically representative model membranes. Our data suggests that PST stiffens the inner mitochondrial membrane (IMM) by being preferentially associated with cardiolipin, which would lead to the relocation and release of cytochrome c. Second, PST has an ordering effect on the lipids and disrupts their distribution within the IMM, which would interfere with the maintenance and functionality of the active forms of proteins in the electron transport chain. These previously unreported findings implicate PST's effect on mitochondrial apoptosis.

Gemini Surfactant Mediated Catansomes for Enhanced Singlet Oxygen Generation of Rose Bengal and Their Phototoxicity against Cancer Cells

Photodynamic therapy (PDT) is an innovative technique for cancer treatment with minimal side effects, based on the use of a photosensitizer, oxygen, and light. Photosensitizers (PSs) have several limitations, that may limit their clinical use, like poor solubilization, self-aggregation, and lack of specific targeting, which can be addressed with the use of nanomaterials. Herein, a unique type of catansomes (CaSs) was prepared using a gemini imidazolium-based surfactant (1,3-bis[(3-octadecyl-1-imidazolio)methyl]benzene dibromide (GBIB) and a double chain surfactant, diaoctyl sodium sulfosuccinate or Aerosol OT (AOT). The formation of CaS GBIB/AOT was optimized in various ethanol/water (E/W) solvent ratios by employing a facile, quick, and most reliable solution-solution mixing method. The CaS was characterized by dynamic light scattering (DLS) and field emission gun scanning electron microscopy (FEG-SEM) techniques. The experimental results reveal that stable CaSs with a spherical shape were obtained at lower concentration (100 μM). Rose Bengal (RB), a PS of the xanthene family, was incorporated into these prepared CaSs, as proven by fluorescence spectroscopy, UV-visible absorption spectroscopy, and confocal laser scanning microscopy. Singlet oxygen (¹O₂) generation studies revealed the relevant role of the E/W solvent ratio as there was a 4-fold boost in the ¹O₂ production for GBIB/AOT in E/W = 50:50 and around 3-fold in E/W = 30:70. Also, the GBIB-rich 80:20 fraction was more efficient in increasing the ¹O₂ generation as compared to the AOT rich fraction (20:80). Further, their phototoxicity was tested in a water-rich solvent ratio (E/W = 30:70) against MCF-7 cells. Upon irradiation with a 532 nm laser (50 mW) for 5 min, RB@GBIB/AOT(20:80) fraction caused 50% decrease in the metabolic activity of MCF-7 cells, and RB@GBIB/AOT(80:20) fraction produced a maximum 85% decrease in cell viability. Furthermore, the enhancement in intracellular ¹O₂ generation by RB@GBIB/AOT, as compared to pure RB, was confirmed with singlet oxygen sensor green (SOSG). This new type of CaS based on gemini surfactants exhibiting a large amount of ¹O₂ generation, holds great interest for several applications, such as use in photomedicine in future.

Immunoisolation of Endosomal Recycling Vesicles from Saccharomyces cerevisiae

Endosomal recycling is essential for the appropriate function of the endosome. During this process, endosomal coat complexes (i.e., retromer, and Mvp1) are recruited to the endosome, and deform its membrane to form recycling vesicles. To further analyze this, we developed a protocol for the immunoisolation of recycling vesicles from budding yeast. This method is a powerful way to characterize endosomal recycling pathways.

Changes in xylem morphology and activity of defense-related enzymes are associated with bean resistance during Fusarium oxysporum colonization

Genetic resistance is the main strategy to control Fusarium wilt in common bean. Despite this, few studies have focused on defense mechanisms involved in bean resistance to Fusarium oxysporum f. sp. phaseoli (Fop). Thus, the present study aimed to investigate the changes in xylem morphology and involvement of phenylpropanoid compounds and their biosynthetic enzymes in bean resistance against Fop. Uirapuru and UFSC-01 genotypes characterized, respectively, as susceptible and resistant were used. In roots and hypocotyls, guaiacol peroxidase (GPX), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO) activities were determined at 0, 1, 2, 3, 4, 5, and 6 days after inoculation (dai), and flavonoids, total phenolics, and lignin content were quantified at 0, 3, and 6 dai. Cross sections of taproots and hypocotyls were examined under epifluorescence (at 1, 3, and 6 dai) and transmission electron (at 6 dai) microscopic to analyze the morphology of xylem cell walls. Overall, there was an increase in the activity of all studied enzymes in resistant bean plants, mainly during advanced colonization stages. Modifications in xylem morphology were more intense in roots of resistant genotype resulting in an increase of occluded cells, organelles, and cell wall strengthening. This study provides evidence that bean resistance is associated with increased phenylpropanoid enzymatic activity and cell wall reinforcement of some xylem cells.

Aspects of Biological Replication and Evolution Independent of the Central Dogma: Insights from Protein-Free Vesicular Transformations and Protein-Mediated Membrane Remodeling

Biological membrane remodeling is central to living systems. In spite of serving as “containers” of whole-living systems and functioning as dynamic compartments within living systems, biological membranes still find a “blue collar” treatment compared to the “white collar” nucleic acids and proteins in biology. This may be attributable to the fact that scientific literature on biological membrane remodeling is only 50 years old compared to ~ 150 years of literature on proteins and a little less than 100 years on nucleic acids. However, recently, evidence for symbiotic origins of eukaryotic cells from data only on biological membranes was reported. This, coupled with appreciation of reproducible amphiphilic self-assemblies in aqueous environments (mimicking replication), has already initiated discussions on origins of life beyond nucleic acids and proteins. This work presents a comprehensive compilation and meta-analyses of data on self-assembly and vesicular transformations in biological membranes—starting from model membranes to establishment of Influenza Hemagglutinin-mediated membrane fusion as a prototypical remodeling system to a thorough comparison between enveloped mammalian viruses and cellular vesicles. We show that viral membrane fusion proteins, in addition to obeying “stoichiometry-driven protein folding”, have tighter compositional constraints on their amino acid occurrences than general-structured proteins, regardless of type/class. From the perspective of vesicular assemblies and biological membrane remodeling (with and without proteins) we find that cellular vesicles are quite different from viruses. Finally, we propose that in addition to pre-existing thermodynamic frameworks, kinetic considerations in de novo formation of metastable membrane structures with available “third-party” constituents (including proteins) were not only crucial for origins of life but also continue to offer morphological replication and/or functional mechanisms in modern life forms, independent of the central dogma.

Macrophage membrane-functionalized nanofibrous mats and their immunomodulatory effects on macrophage polarization

Immunomodulation is an important phenomenon in the normal mammalian host response toward an injury, and plays a critical role in tissue regeneration and regenerative medicine. Different phenotypes of macrophages show an array of activation states compassing pro-inflammatory to pro-alleviating cells, which are the critical players to modulate immune response and tissue regeneration. In this study, macrophage membranes of different phenotypes (macrophages (M0), classically activated macrophages (M1) and alternatively activated macrophages (M2)) were coated onto poly-ε-caprolactone (PCL) nanofibers to acquire exterior surface proteins and similar functions of the natural membranes. In vitro results unveiled that these nanofibers, especially the M2-PCL nanofibers, can suppress the activities of inflammatory markers such as TNF-α and IL-1β, and stimulate anti-inflammatory markers such as Arg-1, IL-10 and TGF-β. In a C57BL/6 mouse model, the macrophage membrane-coated nanofibers, especially the M2-PCL nanofibers, displayed minimal cellular infiltration and low collagen deposition, increased anti-inflammatory CD206 and decreased inflammatory CD86 levels. The M2-PCL nanofibers most effectively neutralized inflammatory chemokines, regulated the expression of inflammation-associated genes as well as anti-inflammatory genes, and showed strong immunomodulatory effects than the PCL, M0-PCL and M1-PCL nanofibers. STATEMENT OF SIGNIFICANCE: Different types of macrophage membrane-functionalized PCL nanofibers were successfully prepared and well characterized. They inherited the surface proteins imitating the source macrophages, and played an important role in limiting cellular infiltration and collagen deposition. These different macrophages and their membrane-coated nanofibers (M0-PCL, M1-PCL and M2-PCL) behaved like their respective source cells. The M2 mimicking M2-PCL nanofibers effectively polarized macrophages to M2 phenotype and decreased the expression of inflammation-associated chemokines and promoted the anti-inflammation in vitro and in vivo, which is critical for tissue regeneration. The mice implanted with the bio-mimicking M2-PCL nanofibers effectively inhibited toll like receptors signaling induced NF-kB and IRF-5 and their target genes such as Edn-1, IL-6, iNOS, TNF-α, etc. compared to the PCL, and M0-PCL and M1-PCL macrophage membrane-coated nanofibers.

On the effects of organic-acids isomers on temperature-responsiveness in wormlike micelles (WLMs) systems

Responsive wormlike micelles (WLMs) consisted of cationic surfactants and organic-acids are fascinating due to their reversible molecular recognition properties. However, it is unknown how the structure of organic-acids alters the stimuli-responsiveness of WLMs systems. Herein, the peculiar nature of temperature-responsive behaviors in three WLMs systems were systematically investigated. These were manufactured by combining N-erucamidopropyl-N,N-dimethylamine (UC₂₂AMPM) with isomers of organic-acids: o-phthalic acid (o-PA), m-phthalic acid (m-PA) and p-phthalic acid (p-PA) at molar ratio of 2:1 (named as o-EAPA, m-EAPA and p-EAPA respectively). The phase behaviors, macro- and micro-rheology, as well as the mechanism of temperature-responsiveness were explored by visual inspection, rheological and optical methods. The results showed that the three systems exhibited different responsiveness with increase of temperature. Among them, the viscosity and viscoelasticity of o-EAPA were gradually decreased with temperature increase from 30 °C to 90 °C. On the other hand, those of p-EAPA were firstly increased and subsequently decreased, exhibiting the highest viscosity during the heating process. This peculiar phenomenon was attributed to the hydrophilic difference of organic-acids isomers, leading to variations of micelle transitions upon temperature increase. This study is the first report of aromatic-acids isomers inducing different on temperature-responsiveness, and finding beneficial for the development of responsive WLMs for different applications.

Antioxidant-containing monoolein aqueous dispersions: a preliminary study

The present study describes a preliminary study on the use of monoolein aqueous dispersions (MADs) as delivery systems for antioxidant molecules, namely, ascorbyl palmitate (AP) and alpha-tocopherol (AT). MAD, produced by emulsifying monoolein (4.5% w/w) in water and poloxamer 407 (0.5% w/w) as emulsifier, was characterized in terms of size, morphology, and antioxidant activity by mean of PCS, cryo-TEM, and (2,2-diphenyl-1-picrylhydrazyl) assay. MAD-AP or MAD-AT gave rise to a bimodal size distribution with mean size around 200 nm. All the preparations stored at 25 °C showed quite stable size at least up to 90 days. Cryo-TEM images confirmed MAD size distribution and indicated different MAD morphologies as a function of the loaded antioxidant molecule. Indeed, in the case of MAD-AP, vesicles and cubosomes with the typical inner cubic structure were observed, while vesicles and hexosomes were shown for MAD-AT. The encapsulation efficiency of both antioxidants reached more than 90% with respect to the total amount of drug used for MAD preparation. Moreover, AP and AT antioxidant activity was retained after encapsulation, and in vitro Franz cell experiments showed that the MAD enabled to better control the drug release. These preliminary results suggest that MAD formulations could be further investigated as a potential delivery system for antioxidant supplementation in dietary or cosmetic fields.

Ferrihydrite nanoparticles entrapped in shear-induced multilamellar vesicles

HYPOTHESIS

Ferrihydrite (Fh) nanoparticles are receiving considerable scientific interest due to their large reactive surface areas, crystalline structures, and nanoparticle morphology. They are of great importance in biogeochemical processes and have the ability to sequester hazardous and toxic substances. Here, the working hypothesis was to entrap fractal-like Fh nanoparticles, with a radius of gyration of 6.2 nm and a primary building block of polydisperse spheres with a radius of 0.8 nm, in a shear-induced multilamellar vesicle (MLV) state using a 40 wt% polyethylene glycol dodecyl ether surfactant.

EXPERIMENTS

Small- and Wide- Angle X-ray scattering revealed the equilibrium state of the non-ionic planar lamellar phase, the Fh dispersion, and their mixture. The MLV state was induced by using a shear flow in a Taylor-Couette geometry of a rheometer.

FINDINGS

The nonionic surfactant initially exhibited a lamellar gel phase with two distinct d-spacings of 11.0 and 9.7 nm, which collapsed into the MLV state under shear flow. The Fh nanoparticles induced bilayer attraction by suppressing lamellar layer undulations, decreasing the d-spacing. These results are helpful in the understanding of the relationship between nanoparticle size and nanoparticle-bilayers interactions and provides insight on Fh encapsulations in a kinetically stable MLVs state.

Self-assembly of miktoarm palm tree-like star copolymers in a selective solvent

Amphiphilic miktoarm star copolymers with one long solvophobic arm (a "stem") and several short solvophilic arms (the "leaves") were studied in a selective solvent using mesoscopic computer simulations. The conventional morphologies (spherical, cylindrical and vesicular) as well as the mixed ones were obtained. However, the resulting diagram of states appeared to be different from the diagram of the linear diblock copolymer with the analogous composition. Namely, the increase of the number of leaves at fixed solvophobic-solvophilic ratio leads to the transition from the vesicles to the cylinders, while the latter ones eventually transform into spherical micelles in the case of highly branched copolymers. The observed effect appears due to the increase of the interfacial area between the collapsed and swollen blocks per single macromolecule. In turn, the increase of the solvent selectivity shifts the stability region of the cylindrical micelles to the region of more symmetric copolymer composition. Meanwhile, the compatibility between the blocks has a weak effect on the resulting morphology. Finally, it was found that the increase in the number of leaves and the simultaneous decrease in their length results in the localization of higher amount of solvophilic segments near the core-solvent interface, which in the case of cylindrical micelles significantly affects the shape of the aggregates making them thinner and longer.

Agonist-induced extracellular vesicles contribute to the transfer of functional bombesin receptor-subtype 3 to recipient cells

Extracellular vesicles (EVs) are important carriers for biomolecules in the microenvironment that greatly promote intercellular and extracellular communications. However, it is unclear whether bombesin receptor-subtype 3 (BRS-3), an orphan G-protein coupled receptor, can be packed into EVs and functionally transferred to recipient cells. In this study, we applied the synthetic agonist and antagonist to activate and inhibit the BRS-3 in HEK293-BRS-3 cells, whose EVs release was BRS-3 activation dependent. The presence of BRS-3 in harvested EVs was further confirmed by an enhanced green fluorescent protein tag. After recipient cells were co-cultured with these EVs, the presence of BRS-3 in the recipient cells was discovered, whose function was experimentally validated. Quantitative proteomics approach was utilized to decipher the proteome of the EVs derived from HEK293-BRS-3 cells after different stimulations. More than 900 proteins were identified, including 51 systematically dysregulated EVs proteins. The Ingenuity Pathway Analysis (IPA) revealed that RhoA signaling pathway was as an essential player for the secretion of EVs. Selective inhibition of RhoA signaling pathway after BRS-3 activation dramatically reversed the increased secretion of EVs. Our data, collectively, demonstrated that EVs contributed to the transfer of functional BRS-3 to the recipient cells, whose secretion was partially regulated by RhoA signaling pathway.

There and back again: Intracellular trafficking, release and recycling of matrix metalloproteinases

Matrix metalloproteinases are a family of zinc-dependent endopeptidases that are involved in a large variety of proteolytic processes in physiological and pathological scenarios, including immune cell surveillance, tissue homeostasis, or tumor cell metastasis. This is based on their ability to cleave a plethora of substrates that include components of the extracellular matrix, but also cell surface-associated and intracellular proteins. Accordingly, a tight regulatory web has evolved that closely regulates spatiotemporal activity of specific MMPs. An often underappreciated mechanism of MMP regulation involves their trafficking to and from specific subcellular sites that require MMP activity only for a certain period. In this review, we focus on the current knowledge of MMP intracellular trafficking, their secretion or surface exposure, as well as their recycling back from the cell surface. We discuss molecular mechanisms that enable these steps, in particular microtubule-dependent motility of vesicles that is driven by molecular motors and directed by vesicle regulatory proteins. Finally, we also point out open questions in the field of MMP motility that may become important in the future.

Preparation and Fluorescent Labeling of Cell-Derived Micelles and Profiling on Glycan Microarrays

Mammalian cell surface lectins mediate many important biological interactions which regulate physiological processes and therefore profiling mammalian cells on glycan microarray is of interest. However, many whole mammalian cells are not compatible with glycomics microarray formats and instead cell-derived micelles are prepared and profiled instead of whole cells as they can accurately represent the parental cell glycome. In this chapter, we describe the preparation of cell-derived micelles from mammalian cells, their labeling using a membrane-incorporating dye, and their profiling on a glycan microarray platform.

Isolation of Synaptic Vesicles from Mammalian Brain

Synaptic vesicles (SVs) store neurotransmitters and undergo a fine-tuned regulatory and dynamic cycle of exo- and endocytosis, which is essential for neurotransmission at chemical synapses. The development of protocols for isolating SVs from biological extracts was a fundamental accomplishment since it allowed for characterizing the molecular properties of SVs using biochemical methods. In this chapter, we describe a modified procedure for isolating SVs from a few g of rodent brain and that can be completed within ~12 h. The protocol involves the preparation of isolated nerve terminals from which SVs are released by osmotic shock and then enriched via various centrifugation steps, followed by size exclusion chromatography as final purification step. The final vesicle fraction is 22-fold enriched in SVs over the starting material, and the final yield of SVs obtained using this protocol is approximately 20 μg of protein per gram of mouse brain. The degree of contamination by other organelles and particles monitored by morphology and immunolabeling compares well with that of the classical protocols.

Cell-Free Membrane Protein Expression into Hybrid Lipid/Polymer Vesicles

Hybrid membranes comprised of diblock copolymers, and phospholipids have gained interest due to their unique properties that result from blending natural and synthetic components. The integration of membrane proteins into these synthetic membranes is an important step towards creating biomembrane systems for uses such as artificial cellular systems, biosensors, and drug delivery vehicles. Here, we outline a technique to create hybrid membranes composed of phospholipids and diblock copolymers. Next, we describe how membrane proteins can be co-translationally integrated into hybrid lipid/polymer membranes using a cell-free reaction. We then outline a method to monitor insertion and folding of a membrane-embedded channel protein into the hybrid membrane using a fluorescent-protein reporter and dye release assay, respectively. This method is expected to be applicable for a wide range of membrane proteins that do not require chaperones for co-translational integration into vesicles and provides a generalized protocol for expressing a membrane protein into a membrane mimetic.

Inspiring biomimetic system based on red blood cell membrane vesicles for effective curcumin loading and release

The aim of this study is to introduce an inspiring biomimetic system based on the red blood cell membrane (RBCM) vesicles for improved encapsulation efficiency and release of curcumin (Cur). Here, the role of the sonication time (0.5, 1.5, 3 and 5 min) on the properties of RBCM-CUR vesicles is investigated. It is determined that the hydrodynamic vesicle size, zeta potential, and release behavior are tunable by changing the sonication time. Noticeably, the average size of vesicles decreased from 163.0 ± 21 nm to 116.3 ± 16 nm by increasing the sonication time from 0.5 to 5 min. Moreover, the drug release value, after 24 h incubation, enhances from 57 to 99% with the expansion of sonication from 0.5 to 5 min. Additionally, the entrapment efficiency of Cur as a model drug is high in whole sonication time, owing to the amphiphilic nature of RBCM. Finally, the RBCM-CUR vesicles are not only cytocompatible, but also could support the attachment and proliferation of fibroblast cells in vitro. The RBCM based system for delivery of Cur could be a promising system for the wound healing applications.

Mechanisms of membrane traffic in plant cells

The organelles of the secretory pathway are characterized by specific organization and function but they communicate in different ways with intense functional crosstalk. The best known membrane-bound transport carriers are known as protein-coated vesicles. Other traffic mechanisms, despite the intense investigations, still show incongruences. The review intends to provide a general view of the mechanisms involved in membrane traffic. We evidence that organelles' biogenesis involves mechanisms that actively operate during the entire cell cycle and the persistent interconnections between the Endoplasmic reticulum (ER), Golgi apparatus, trans-Golgi network (TGN) and endosomes, the vacuolar complex and the plasma membrane (PM) may be seen as a very dynamic membrane network in which vesicular traffic is part of a general maturation process.

Transformable vesicles for cancer immunotherapy

Immunotherapy that utilizes the human immune system to fight cancer represents a revolutionary method for cancer treatment. Immunotherapeutic agents that trigger the immune response should be carefully delivered to the desired site to maximize immunotherapy effectiveness and minimize side effects. Vesicles offer the possibility of encapsulating both hydrophilic and hydrophobic drugs and thus serve as a promising delivery tool. As multiple irreconcilable requirements exist at different transport stages, developing vesicles transformable in response to given stimuli is of great significance. In this review, we first introduced various vesicle types used for immunotherapy. Furthermore, the typical stimuli that trigger vesicle transformation and the usually generated transformation styles were described. Focusing on three aspects of antigen-presenting cell (APC)/T cell activation, tumor microenvironment (TME) amelioration, and immunogenic cell death (ICD)-induced immunotherapy, we reviewed recently reported transformable vesicles for tumor treatment. Finally, we put forward possible directions for future research and clinical translation.

Transition kinetics of mixed lipid:photosurfactant assemblies studied by time-resolved small angle X-ray scattering

HYPOTHESIS

Photoswitchable surfactants are used in the design of many light-responsive colloids and/or self-assemblies. Photo-isomerization enables to control molecular equilibrium, and triggers transient reorganizations with possibly out-of-equilibrium intermediate states that have been overlooked. Here, we address this question by an in depth structural investigation of intermediate lipid-surfactant assemblies that occur during fast isothermal photo-triggered transition in lipid:surfactant mixtures.

EXPERIMENTS

The structural parameters of mixed assemblies of azobenzene-containing cationic surfactant (AzoTMA) and dioleoylphosphatidylcholine (DOPC) lipids were studied by light scattering and time-resolved small angle X-ray scattering. Structural and compositional information about the assemblies and unimers in bulk were determined at the photostationary states, as well as at intermediate kinetic states formed during UV or blue light illumination.

FINDINGS

DOPC:AzoTMA systems form mixed assemblies representative of phospholipid:cationic surfactant mixtures, that evolve from spheroid, to rod-like micelles, and vesicles with increasing DOPC fraction. Transient assemblies detected during the photo-triggered kinetics are similar to the ones found in stationary states. But changes of AzoTMA unimers in bulk can be considerably faster than mass reorganizations of the mixed assemblies, suggesting that out-of-equilibrium conditions are transiently reached. Mass reorganization of the surfactant-enriched assemblies is much faster than in the lipid enriched ones, providing insight into the role of lipids in a slow reorganization of the assemblies.

Ectoine Effect on Mechanical Properties of Vesicles in Aqueous Solution

The mechanical properties of the vesicles incorporated with ectoine were studied using atomic force microscope (AFM). The vesicles were prepared with dipalmitoylphosphatidylcholine (DPPC) by changing only the ratio of the ectoine to DPPC. After the vesicles were adsorbed on the mica substrate and their morphology were characterized, the plot of an AFM tip displacement versus the tip deflection was acquired by monitoring the behavior of the tip into the vesicle. The breakthrough of the tip into the vesicle was observed to occur twice. Each breakthrough represented a penetration of the tip into the top and bottom portions of the vesicle, respectively. The force data between the pre-contact and the first breakthrough were comparable with the Hertzian model to estimate Young's modulus and the bending modulus of the vesicles. Both moduli decreased proportionally with the increase in the ratio of ectoine to lipid up to 0.5. However, above 0.5, the moduli were slightly changed with the increase. These results of the mechanical properties appear to be due to the osmotic and volumetric effect on the headgroup packing disruption.