Cell-derived Membrane Research Articles

Cell membrane fusion composite lipid nanocarrier: preparation and evaluation of anti-tumor effects.

With the advancements in nanotechnology and biomaterials science, the development of nanodrug delivery systems (Nano-DDSs) has provided opportunities for the realization of precise targeted treatment of malignant tumors. Liposomes have become a type of DDS with early clinical application and mature development due to their excellent tissue-targeting capacity and outstanding biocompatibility. However, several obstacles remain, such as recognition and clearance by the immune system, a short half-life, and poor tumor targeting. To address these problems, we propose a new method to transform liposomes, using fusion to reassemble the extracted natural cell membranes and artificial phospholipids to form a composite nanolipid carrier (recombined lipid nanocarriers (RLNs)). We evaluated the different types of cell membrane composite lipid nanocarriers based on parameters such as particle size, stability, drug loading and release capabilities, in vitro and in vivo tumor-targeting efficacy, and safety. The results indicated that these novel tumor cell-derived membrane fusion lipid nanocarriers exhibited promising antitumor effects and safety profiles, offering insights for precision cancer treatment.

Monitoring concentration and lipid signature of plasma extracellular vesicles from HR+ metastatic breast cancer patients under CDK4/6 inhibitors treatment.

Extracellular vesicles (EVs) are cell-derived small membrane structures that transport various molecules. They have emerged as potential circulating biomarkers for monitoring responses to cancer therapies. This study aimed to comprehensively characterize plasma-carried EVs in hormone receptor-positive (HR+) metastatic breast cancer (MBC) patients treated with first-line CDK4/6 inhibitors (iCDK4/6) combined with endocrine therapy. MBC patients were classified into three groups based on their response to therapy: resistant, intermediate or sensitive. In a prospective cohort, we monitored the concentration of circulating EVs, analyzed their lipid signature and correlated these factors with treatment response. To facilitate the translation of EV research to clinical practice, we established a three-step procedure: (1) EVs were isolated from plasma using semi-automatized size exclusion chromatography (SEC); (2) EV concentration, termed vesiclemia, was determined by drop counting via interferometric light microscopy (ILM); and (3) EV lipid composition was analyzed by mass spectrometry. ILM-based vesiclemia values were highly fluctuating upon iCDK4/6 treatment, while early increase associated with accelerated progression. Of note, vesiclemia remained a steady parameter over a 1-year period in age-matched healthy women. Additionally, analysis of the EV cargo unveiled a distinct sphingolipid profile, characterized by increased levels of ceramides and sphingomyelins in resistant patients within the first 2 months of treatment. Based on 16 sphingolipid species, sensitive and resistant patients were correctly classified with an overall accuracy of 82%. This specific sphingolipid pattern was exclusively discernible within EVs, and not in plasma, highlighting the significance of EVs in the early prediction of individual responses to iCDK4/6 and disease progression. Overall, this study provides insights of the longitudinal characterization of plasma-borne EVs in both a healthy group and HR+ MBC patients under iCDK4/6 therapies. Combined vesiclemia and EV sphingolipid profile emphasize the promising potential of EVs as non-invasive biomarkers for monitoring early treatment response.

Multiplex analysis of cancer cells treated with induced mesenchymal stem cell membrane vesicles

BACKGROUND: Extracellular vesicles (EVs) are membrane-derived vesicles released by cells into the extracellular space, playing a crucial role in intercellular communication and regulating a range of biological processes. These vesicles are found in tumor tissue, where they serve as mediators in signal transduction between tumor cells and the cells of the microenvironment. Similar to their parent mesenchymal stem cells (MSCs), extracellular vesicles demonstrate contradictory effects on tumor development. Studies have shown that MSC-derived EVs promote tumor growth; however, some research has also demonstrated their inhibitory role. AIM: The aim is to assess the effect of mesenchymal stem cell-derived membrane vesicles on the molecular composition of cancer cells. METHODS: Induced membrane vesicles were obtained from mesenchymal stem cells through treatment with cytochalasin B. Mesenchymal stem cells were initially sourced from adipose tissue. To simulate intercellular communication between tumor cells and MSCs, induced membrane vesicles were applied at varying protein concentrations to recipient cells (SH-SY5Y, PC3, MCF7). The bicinchoninic acid method was used to measure the total protein concentration isolated from human cells/induced membrane vesicles. Subsequently, the molecular composition of the recipient cells after the application of induced membrane vesicles was analyzed using multiplex assays. RESULTS: We determined that after the application of MSC-derived membrane vesicles to cancer cells, significant alterations occur in the expression of numerous biologically active molecules, including cytokines, chemokines, and growth factors. Specifically, increased concentrations of growth factor FGF-2, cytokines G-CSF, Fractalkine, IL-12p40, IL-9, IL-4, IL-6, IL-8, and chemokines IP-10, MCP-1, among others, were observed. The analysis also revealed that most of these molecules are associated with cell proliferation, migration, and immune response. CONCLUSION: Mesenchymal stem cell-derived membrane vesicles are capable of altering the molecular profile of cancer cells, increasing the concentration of molecules linked to cell survival and migration.

P-040 The characteristic of human seminal plasma extracellular vesicle (SPEVs) profiles with different sperm features in a large cohort of 309 Taiwanese men

Abstract Study question To investigate human seminal plasma extracellular vesicle profiles in different sperm characteristics and their potential clinical application. Summary answer Normozoospermic semen has significantly higher SPEV concentration than asthenozoospermic or oligozoospermic samples. Moreover, SPEV concentration was highly correlated with total motile sperm count. What is known already Seminal plasma extracellular vesicles (SPEVs) are cell-derived membrane structures that carry proteins, nucleic acid, and lipids, which can modify the constitution and biological function of sperm. However, the characteristics of SPEVs in different sperm features remained unclear. Study design, size, duration From January 2021 to September 2023, 309 men who visited the NCKUH andrology clinic agreed to collect semen samples for this study, which the Institutional Review Board has approved. Participants/materials, setting, methods Semen parameters were measured by the X1 CASA system (Bonraybio, Taiwan). SPEVs were isolated by size exclusion chromatography column and ExoQuick™. Next, the SPEVs’ concentration and size distribution were performed with nanoparticle tracking analysis. The Kruskal-Wallis test calculated comparison in multiple groups, and Dunn’s multiple comparison tests accessed group-group comparison. The Pearson correlation coefficient r of exosome concentration with individual sperm parameters was calculated. A p-value less than 0.05 was set as statistical significance. Main results and the role of chance Among them, 59 semen samples were presented with normozoospermia, 36 were oligozoospermia, 73 were asthenozoospermia, and 141 samples had no sperm in semen. Among these 141 azoospermic men, 89 men are characterized by non-obstructive azoospermia (NOA), while the other 52 men had a vasectomy. Our data showed that normozoospermic semen has significantly higher SPEV concentration than asthenozoospermic or oligozoospermic semen samples (26 x109 [IQR 17.25 x109-56.25 x109] versus 12 x109 [IQR 5.6 x109-19.5 x109] versus 15.5 x109 [IQR 8.575 x109-26.75 x109], p = 0.0001). Nevertheless, azoospermic semen has the lowest SPEV concentrations. The concentration of SPEVs from infertile men diagnosed with NOA is slightly lower than vasectomized men (3.9 x109 [IQR 1.875 x109-7.675 x109] versus 5.4 x109 [IQR 2.9 x109-8 x109], p = 0.0001). The Pearson r coefficient of SPEV concentration with sperm concentration, progressive motility, and total motile sperm count was 0.238, 0.303, and 0.451, respectively. (P < 0.0001) Limitations, reasons for caution Because our data were collected from Taiwanese men, it is not yet known whether SPEV profiles differ among races. Wider implications of the findings Human SPEV concentration and its bio-content may be a potential non-invasive biomarker to predict the male reproductive outcome. Trial registration number not applicable

Numerical model for electrogenic transport by the ATP-dependent potassium pump KdpFABC

In vitro assays of ion transport are an essential tool for understanding molecular mechanisms associated with ATP-dependent pumps. Because ion transport is generally electrogenic, principles of electrophysiology are applicable, but conventional tools like patch-clamp are ineffective due to relatively low turnover rates of the pumps. Instead, assays have been developed to measure either voltage or current generated by transport activity of a population of molecules either in cell-derived membrane fragments or after reconstituting purified protein into proteoliposomes. In order to understand the nuances of these assays and to characterize effects of various operational parameters, we have developed a numerical model to simulate data produced by two relevant assays: fluorescence from voltage-sensitive dyes and current recorded by capacitive coupling on solid supported membranes. Parameters of the model, which has been implemented in Python, are described along with underlying principles of the computational algorithm. Experimental data from KdpFABC, a K+ pump associated with P-type ATPases, are presented, and model parameters have been adjusted to mimic these data. In addition, effects of key parameters such as nonselective leak conductance and turnover rate are demonstrated. Finally, simulated data are used to illustrate the effects of capacitive coupling on measured current and to compare alternative methods for quantification of raw data.

Role of exosomes in exacerbations of asthma and COPD: a systematic review.

Asthma and chronic obstructive pulmonary disease are chronic respiratory disorders characterized by airways obstruction and chronic inflammation. Exacerbations lead to worsening of symptoms and increased airflow obstruction in both airways diseases, and they are associated with increase in local and systemic inflammation. Exosomes are cell-derived membrane vesicles containing proteins, lipids, and nucleic acids that reflect their cellular origin. Through the transfer of these molecules, exosomes act as mediators of intercellular communication. Via selective delivery of their contents to target cells, exosomes have been proved to be involved in regulation of immunity and inflammation. Although, exosomes have been extensively investigated in different diseases, little is currently known about their role in asthma and COPD pathogenesis, and particularly in exacerbations. This review aims to systemically assess the potential role of exosomes in asthma and COPD exacerbations.

Transforming tumor immune microenvironments with a novel systemic enveloped oncolytic virotherapy targeting all tumor sites.

2559 Background: Systemic oncolytic virotherapy offers a promising solution for treating both local and metastatic diseases. However, the rapid inactivation of virotherapeutics by the immune system has resulted in disappointing clinical efficacy. To address this challenge, we have built a new program (ImmunoNova) to develop a cellular-based technology that protects oncolytic virotherapy, allowing for successful targeting of the therapy to tumor sites and effectively overcoming clinical challenges. This approach involves utilizing a newly selected and engineered, tumor-selective strain of vaccinia virus (RT-01). This strain produces high levels of extracellular enveloped virions (EEVs) that contain a second human cell-derived membrane, providing augmented protection against elimination by the immune system when administered systemically. The process requires specific manufacturing methods to preserve this crucial second human cellular membrane. Methods: The resistance of the manufactured enveloped RT-01 (envRT-01) virus against human humoral immunity and its rapid spread were assessed ex-vivo using a plaque assay. EnvRT-01 was administered in various xenograft and syngeneic models to evaluate its specificity in targeting tumors and its therapeutic efficacy, either alone or in combination with cell therapies. The amplification of virus-encoded RFP was monitored using an imaging system. Additionally, flow cytometry and immunohistochemistry (IHC) were employed to analyze immune infiltration in both treated and untreated tumors. Results: EnvRT-01 particles exhibited an approximately 80% survival rate in the presence of active complement. In animal studies, a single systemic dose of envRT-01 selectively targeted three distinct human cancer indications (lung, melanoma, head & neck), leading to the suppression of tumor growth in all three cases. Similarly, in an immunocompetent syngeneic lung tumor model, envRT-01 effectively targeted and reduced multiple murine lung tumors with just a low single dose of treatment. EnvRT-01 was capable of targeting and expressing viral-encoded proteins in all tumor sites and drastically modifying the tumor immune microenvironment, favoring an anti-tumor immune phenotype and facilitating other cell therapies such as innate-based cell therapies. Conclusions: The development of this innovative enveloped oncolytic virotherapeutic, coupled with advancements in its manufacturing methods, opens up new possibilities in the realm of cancer therapy. It addresses the limitations posed by untargetable and untreatable metastatic diseases, presenting a transformative solution with broad implications for the field.

Free-Standing DNA Origami Superlattice to Facilitate Cryo-EM Visualization of Membrane Vesicles.

Technological breakthroughs in cryo-electron microscopy (cryo-EM) methods open new perspectives for highly detailed structural characterizations of extracellular vesicles (EVs) and synthetic liposome-protein assemblies. Structural characterizations of these vesicles in solution under a nearly native hydrated state are of great importance to decipher cell-to-cell communication and to improve EVs' application as markers in diagnosis and as drug carriers in disease therapy. However, difficulties in preparing holey carbon cryo-EM grids with low vesicle heterogeneities, at low concentration and with kinetic control of the chemical reactions or assembly processes, have limited cryo-EM use in the EV study. We report a straightforward membrane vesicle cryo-EM sample preparation method that assists in circumventing these limitations by using a free-standing DNA-affinity superlattice for covering holey carbon cryo-EM grids. Our approach uses DNA origami to self-assemble to a solution-stable and micrometer-sized ordered molecular template in which structure and functional properties can be rationally controlled. We engineered the template with cholesterol-binding sites to specifically trap membrane vesicles. The advantages of this DNA-cholesterol-affinity lattice (DCAL) include (1) local enrichment of artificial and biological vesicles at low concentration and (2) isolation of heterogeneous cell-derived membrane vesicles (exosomes) from a prepurified pellet of cell culture conditioned medium on the grid.

Establishing Salvia miltiorrhiza-Derived Exosome-like Nanoparticles and Elucidating Their Role in Angiogenesis.

Exosomes are multifunctional, cell-derived nanoscale membrane vesicles. Exosomes derived from certain mammalian cells have been developed as angiogenesis promoters for the treatment of myocardial ischemia-reperfusion injury, as they possess the capability to enhance endothelial cell proliferation, migration, and angiogenesis. However, the low yield of exosomes derived from mammalian cells limits their clinical applications. Therefore, we chose to extract exosome-like nanoparticles from the traditional Chinese medicine Salvia miltiorrhiza, which has been shown to promote angiogenesis. Salvia miltiorrhiza-derived exosome-like nanoparticles offer advantages, such as being economical, easily obtainable, and high-yielding, and have an ideal particle size, Zeta potential, exosome-like morphology, and stability. Salvia miltiorrhiza-derived exosome-like nanoparticles can enhance the cell viability of Human Umbilical Vein Endothelial Cells and can promote cell migration and improve the neovascularization of the cardiac tissues of myocardial ischemia-reperfusion injury, indicating their potential as angiogenesis promoters for the treatment of myocardial ischemia-reperfusion injury.

Cutting-Edge HEK293T Protein-Integrated Lipid Nanostructures: Boosting Biocompatibility and Efficacy.

Recently, artificial exosomes have been developed to overcome the challenges of natural exosomes, such as production scalability and stability. In the production of artificial exosomes, the incorporation of membrane proteins into lipid nanostructures is emerging as a notable approach for enhancing biocompatibility and treatment efficacy. This study focuses on incorporating HEK293T cell-derived membrane proteins into liposomes to create membrane-protein-bound liposomes (MPLCs), with the goal of improving their effectiveness as anticancer therapeutics. MPLCs were generated by combining two key elements: lipid components that are identical to those in conventional liposomes (CLs) and membrane protein components uniquely derived from HEK293T cells. An extensive comparison of CLs and MPLCs was conducted across multiple in vitro and in vivo cancer models, employing advanced techniques such as cryo-TEM (tramsmission electron microscopy) imaging and FT-IR (fourier transform infrared spectroscopy). MPLCs displayed superior membrane fusion capabilities in cancer cell lines, with significantly higher cellular uptake. Additionally, MPLCs maintained their morphology and size better than CLs when exposed to FBS (fetal bovine serum), suggesting enhanced serum stability. In a xenograft mouse model using HeLa and ASPC cancer cells, intravenous administration of MPLCs MPLCs accumulated more in tumor tissues, highlighting their potential for targeted cancer therapy. Overall, these results indicate that MPLCs have superior tumor-targeting properties, possibly attributable to their membrane protein composition, offering promising prospects for enhancing drug delivery efficiency in cancer treatments. This research could offer new clinical application opportunities, as it uses MPLCs with membrane proteins from HEK293T cells, which are known for their efficient production and compatibility with GMP (good manufacturing practice) standards.

T lymphocyte-derived immunogenic hybrid nanovesicles for immunosuppression reversion and boosted photothermal immunotherapy

Photothermal therapy (PTT) can mediate the immunogenic cell death (ICD) of tumors through photothermal transformation, thus releasing tumor-associated antigens (TAAs) and damage-associated molecular patterns (DAMPs) to stimulate the maturation of dendritic cells (DCs) and elicit the immune response against tumors. However, PTT-mediated upregulation of the immune checkpoint molecule programmed cell death ligand 1 (PD-L1) will cause the immune evasion of tumor cells and thus increases the immunosuppression of cytotoxic T lymphocytes (CTLs), resulting in restricted photothermal immune activation. Taking advantage of the high expression of programmed cell death protein 1 (PD-1) in T lymphocytes, we develop an immunogenic photothermal hybrid nanovesicle to reverse immunosuppression and enhance PTT-induced ICD. The hybrid vesicle (TMVL-I) is constructed by phospholipid bilayer fusion of T cell-derived membrane vesicle (TMV) with high PD-1 expression and the indocyanine green (ICG)-loaded thermosensitive liposome (L-I). TMVL-Is bind to the tumor cells with PTT-induced upregulation of PD-L1, effectively blocking the PD-1/PD-L1 pathway between CTLs and tumor cells, thus reversing PD-L1-mediated tumor immunosuppression and intensifying photothermal-induced ICD effects. These processes significantly induce the maturation of DCs and enhance the infiltration of CTLs into both primary and distal tumors and the activation of spleen CTLs, strongly inhibiting the growth of B16 xenograft tumors and greatly improving the survival rate of B16 xenograft mice. This work provides a feasible strategy for immunosuppressive microenvironment reprogramming-based combination therapy.

Lipid Peroxidation Drives Liquid-Liquid Phase Separation and Disrupts Raft Protein Partitioning in Biological Membranes.

The peroxidation of membrane lipids by free radicals contributes to aging, numerous diseases, and ferroptosis, an iron-dependent form of cell death. Peroxidation changes the structure and physicochemical properties of lipids, leading to bilayer thinning, altered fluidity, and increased permeability of membranes in model systems. Whether and how lipid peroxidation impacts the lateral organization of proteins and lipids in biological membranes, however, remains poorly understood. Here, we employ cell-derived giant plasma membrane vesicles (GPMVs) as a model to investigate the impact of lipid peroxidation on ordered membrane domains, often termed membrane rafts. We show that lipid peroxidation induced by the Fenton reaction dramatically enhances the phase separation propensity of GPMVs into coexisting liquid-ordered (Lo) and liquid-disordered (Ld) domains and increases the relative abundance of the disordered phase. Peroxidation also leads to preferential accumulation of peroxidized lipids and 4-hydroxynonenal (4-HNE) adducts in the disordered phase, decreased lipid packing in both Lo and Ld domains, and translocation of multiple classes of raft proteins out of ordered domains. These findings indicate that the peroxidation of plasma membrane lipids disturbs many aspects of membrane rafts, including their stability, abundance, packing, and protein and lipid composition. We propose that these disruptions contribute to the pathological consequences of lipid peroxidation during aging and disease and thus serve as potential targets for therapeutic intervention.

Novel Cancer Immunotherapy Using Cell-Derived Membrane Vesicles Orchestrates Multimodal Antitumor Immunity

Cancer immunotherapy has emerged as a promising therapy for hematological malignancies. Although multiple immunotherapeutics are currently available in the clinic such as chimeric antigen receptor-engineered T-cell therapy (CAR-T cell therapy) and bispecific T-cell engager (BiTE), their long-term efficacy is still insufficient in most of the cases. Simultaneous inputs of multiple signals may provide more optimal T-cell activation and overcome the immunosuppressive tumor microenvironment (TME), which results in a durable therapeutic effect. However, integrating multifaceted immunomodulatory signals into a single drug or cell is technically difficult. To overcome these limitations, we developed nanosized cell-derived membrane vesicles (MVs) that orchestrate multimodal antigen-specific antitumor immunity in endogenous T cells. We isolated MVs with 100-150 nm in size and intact membrane-bound proteins from the HLA-negative leukemia cell line K562 by mechanical homogenization followed by isolation of the plasma membrane fraction using magnetic beads and ultracentrifugation. MVs can be loaded with a desired combination of immunomodulatory molecules on the surface by preparing cells stably transduced with those proteins. First, K562 cells were genetically engineered with a membrane-bound form of the anti-CD3/CD19 BiTE and homogenized to form BiTE-expressing MVs. When co-cultured with T cells and CD19-positive leukemia cell line NALM-6, MVs loaded with anti-CD3/CD19 BiTE induced potent cytotoxic activity in nonspecific T cells in a dose-dependent manner. To provide optimal T-cell activation, we further loaded MVs with a variety of immunostimulatory molecules including costimulatory ligands (CD80 and 4-1BBL) and cytokines (IL-7 and IL-15) on the surface. The generated antitumor MVs simultaneously induced multiple immunostimulatory signals in T cells, resulting in superior proliferation, cytokine production, and cytolytic functions compared with MVs loaded with BiTE alone. Intriguingly, MVs activated T cells only in the presence of target tumor cells, which is considered to provide a safety advantage in clinical settings. Changing the antitumor mAb sequences of the BiTE enabled to generate MVs against any type of antigen including B cell maturation antigen (BCMA), EGFR, and mesothelin. To test functions of our MVs in vivo, NSG mice were transplanted with NALM-6 and then infused with human peripheral blood T cells. While infusion of T cells alone did not contribute to controlling leukemia progression, infusion of anti-CD19 MVs with CD80, 4-1BBL, IL-7, and Il-15 induced potent antitumor response. Repeated infusion of MVs further augmented their therapeutic efficacy. To overcome the immunosuppressive TME, we additionally loaded MVs with immune checkpoint inhibitors (anti-PD-1 and anti-CTLA-4 antibody), TGF-b receptors to trap TGF-b, and inflammatory cytokines (IL-12 and IL-18) that activate both T cells and myeloid cells in the TME. Immunocompetent Balb/c mice were subcutaneously inoculated with colon carcinoma cell line CT26 ectopically expressed with CD19 and treated with MVs targeting CD19. The injected MVs converted tumor-associated M2-type macrophages into an inflammatory phenotype and promoted CD8+ T cell infiltration within the TME, resulting in better control of tumor progression in in vivo solid tumor mouse models. K562 cells are highly sensitive to NK cells because they endogenously express several ligands for NK cell activation receptors such as MIC-A and MIC-B, and lack the expression of HLA class I that represses NK cell activation. K562-derived MVs induced potent cytotoxic activity in NK cells against NK-cell-resistant myeloma cell line MM1S in an antigen-specific manner. In summary, this novel technology enables to deliver desired combinations of antitumor immune signals to not only T cells but also NK cells and other types of immune cells, which can transmit superior therapeutic efficacy against the tumor cells that are resistant to the present immunotherapeutics.

Neural cell membrane-coated DNA nanogels as a potential target-specific drug delivery tool for the central nervous system

A major bottleneck in drug/gene delivery to enhance tissue regeneration after injuries is to achieve targeted delivery to the cells of interest. Unfortunately, we have not been able to attain effective targeted drug delivery in tissues due to the lack of efficient delivery platforms. Since specific cell-cell interactions exist to impart the unique structure and functionality of tissues and organs, we hypothesize that such specific cellular interactions may also be harnessed for drug delivery applications in the form of cell membrane coatings. Here, we employed neural cell-derived membrane coating technique on DNA nanogels to improve target specificity. The efficacy of neural cell membrane-coated DNA nanogels (NCM-nanogels) was demonstrated by using four types of cell membranes derived from the central nervous system (CNS), namely, astrocytes, microglia, cortical neurons, and oligodendrocyte progenitor cells (OPCs). A successful coating of NCMs over DNA nanogels was confirmed by dynamic light scattering, zeta potential measurements and transmission electron microscopy. Subsequently, an overall improvement in cellular uptake of NCM-nanogels over uncoated DNA nanogels (p < 0.005) was seen. Additionally, we observed a selective uptake of OPC membrane-coated DNA nanogels (NCM-O mem) by oligodendrocytes over other cell types both in vitro and in vivo. Our quantitative polymerase chain reaction (qPCR) results also showed selective and effective gene knockdown capacity of NCM-O mem for OPC transfection. The findings in this work may be beneficial for future drug delivery applications targeted at the CNS.

Kappa-carrageenan based hybrid hydrogel for soft tissue engineering applications.

Biological materials such as cell-derived membrane vesicles have emerged as alternative sources for molecular delivery systems, owing to multicomponent features, the inherent functionalities and signaling networks, and easy-to-carry therapeutic agents with various properties. Herein, red blood cell membrane (RBCM) vesicle-laden methacrylate kappa-carrageenan (KaMA) composite hydrogel is introduced for soft tissue engineering. Results revealed that the characteristics of hybrid hydrogels were significantly modulated by changing the RBCM vesicle content. For instance, the incorporation of 20% (v/v) RBCM significantly enhanced compressive strength from 103 ± 26 kPa to 257 ± 18 kPa and improved toughness under the cyclic loading from 1.0 ± 0.4 kJ m-3to 4.0 ± 0.5 kJ m-3after the 5thcycle. RBCM vesicles were also used for the encapsulation of curcumin (CUR) as a hydrophobic drug molecule. Results showed a controlled release of CUR over three days of immersion in PBS solution. The RBCM vesicles laden KaMA hydrogels also supportedin vitrofibroblast cell growth and proliferation. In summary, this research sheds light on KaMA/RBCM hydrogels, that could reveal fine-tuned properties and hydrophobic drug release in a controlled manner.

Pravastatin reduces plasma levels of extracellular vesicles in pregnancies at high risk of term preeclampsia.

Introduction: Elevated plasma levels of extracellular vesicles have been associated with impaired placentation, angiogenesis imbalance, intravascular inflammation, and endothelial dysfunction in women with preeclampsia, thus suggesting that circulating vesicles may be a good therapeutic target for the treatment of the disease. Recently, statins have been considered a potential treatment for the prevention of preeclampsia because of their pleiotropic effects, including the improvement of endothelial dysfunction and inhibition of inflammatory responses. However, the effects of these drugs on circulating vesicles concentration in women at risk of preeclampsia have not been established. Herein, we aimed to assess the effects of pravastatin on circulating extracellular vesicle generation in women at high risk of term preeclampsia. Methods: In a sample of 68 singleton pregnant women participating in the multicenter, double-blind, placebo-controlled STATIN trial (Nº EducraCT 2016-005206-19 ISRCTN), 35 women received a placebo and 33 women received a 20mg/day dose of pravastatin for approximately 3weeks (from 35 to 37weeks of gestation until delivery). Large extracellular vesicles were characterized and quantified by flow cytometry using annexin V and cell-specific antibodies directed against platelet, endothelial, leukocyte, and syncytiotrophoblast cell surface markers. Results: In women who received the placebo, a significant increase in the plasma levels of large extracellular vesicles from platelets (34%, p < 0.01), leukocytes (33%, p < 0.01), monocytes (60%, p < 0.01), endothelial cells (40%, p < 0.05), and syncytiotrophoblast cells (22%, p < 0.05) were observed. However, treatment with pravastatin significantly reduced the plasma levels of large extracellular vesicles from platelets (42%, p < 0.001), leukocytes (25%, p < 0.001), monocytes (61%, p < 0.001), endothelial cells (69%, p < 0.001), activated endothelial cells (55%, p < 0.001), and syncytiotrophoblast cells (44%, p < 0.001). Discussion: These results indicate that pravastatin reduces the levels of activated cell-derived membrane vesicles from the maternal vasculature, blood, and placental syncytiotrophoblast of women at high risk of term preeclampsia, suggesting that this statin may be beneficial in reducing endothelial dysfunction and pro-inflammatory and pro-coagulatory state characteristics of the disease.

Development of an Effective Functional Lipid Anchor for Membranes (FLAME) for the Bioorthogonal Modification of the Lipid Bilayer of Mesenchymal Stromal Cells.

The glycosylation of cellular membranes is crucial for the survival and communication of cells. As our target is the engineering of the glycocalyx, we designed a functionalized lipid anchor for the introduction into cellular membranes called Functional Lipid Anchor for MEmbranes (FLAME). Since cholesterol incorporates very effectively into membranes, we developed a twice cholesterol-substituted anchor in a total synthesis by applying protecting group chemistry. We labeled the compound with a fluorescent dye, which allows cell visualization. FLAME was successfully incorporated in the membranes of living human mesenchymal stromal cells (hMSC), acting as a temporary, nontoxic marker. The availability of an azido function─a bioorthogonal reacting group within the compound─enables the convenient coupling of alkyne-functionalized molecules, such as fluorophores or saccharides. After the incorporation of FLAME into the plasma membrane of living hMSC, we were able to successfully couple our molecule with an alkyne-tagged fluorophore via click reaction. This suggests that FLAME is useful for the modification of the membrane surface. Coupling FLAME with a galactosamine derivative yielded FLAME-GalNAc, which was incorporated into U2OS cells as well as in giant unilamellar vesicles (GUVs) and cell-derived giant plasma membrane vesicles (GPMVs). With this, we have shown that FLAME-GalNAc is a useful tool for studying the partitioning in the liquid-ordered (Lo) and the liquid-disordered (Ld) phases. The molecular tool can also be used to analyze the diffusion behavior in the model and the cell membranes by fluorescence correlation spectroscopy (FCS).

Extracellular Vesicles and Infection: From Hijacked Machinery to Therapeutic Tools.

Extracellular vesicles (EVs) comprise a broad range of secreted cell-derived membrane vesicles. Beyond their more well-characterized role in cell communication, in recent years, EVs have also been shown to play important roles during infection. Viruses can hijack the biogenesis of exosomes (which are small EVs) to promote viral spreading. Additionally, these exosomes are also important mediators in inflammation and immune responses during both bacterial and viral infections. This review summarizes these mechanisms while also describing the impact of bacterial EVs in regulating immune responses. Finally, the review also focuses on the potential and challenges of using EVs, in particular, to tackle infectious diseases.

Role of Epicardial Adipose Tissue Secretome on Cardiovascular Diseases.

Obesity and insulin resistance are associated with the inflamed and defective adipose tissue (AT) phenotype, and are established risk factors for cardiovascular diseases (CVDs). Extracellular vesicles (EVs) are a heterogeneous group of cell-derived lipid membrane vesicles involved in the onset and development of many pathologies, including insulin resistance, diabetes, and CVDs. The inflammation associated with overweight and obesity triggers the transition of the AT secretome from healthy to pathological, with a consequent increased expression of pro-inflammatory mediators. Epicardial adipose tissue (EAT) is a specialized fat depot that surrounds the heart, in direct contact with the myocardium. Recently, the role of EAT in regulating the physiopathology of many heart diseases has been increasingly explored. In particular, the EAT phenotype and derived EVs have been associated with the onset and exacerbation of CVDs. In this review, we will focus on the role of the AT secretome in the case of CVDs, and will discuss the beneficial effects of EVs released by AT as promising therapeutic candidates.

Extracellular Vesicles and Intercellular Communication: Challenges for In Vivo Molecular Imaging and Tracking.

Extracellular vesicles (EVs) are a heterogeneous class of cell-derived membrane vesicles released by various cell types that serve as mediators of intercellular signaling. When released into circulation, EVs may convey their cargo and serve as intermediaries for intracellular communication, reaching nearby cells and possibly also distant organs. In cardiovascular biology, EVs released by activated or apoptotic endothelial cells (EC-EVs) disseminate biological information at short and long distances, contributing to the development and progression of cardiovascular disease and related disorders. The significance of EC-EVs as mediators of cell-cell communication has advanced, but a thorough knowledge of the role that intercommunication plays in healthy and vascular disease is still lacking. Most data on EVs derive from in vitro studies, but there are still little reliable data available on biodistribution and specific homing EVs in vivo tissues. Molecular imaging techniques for EVs are crucial to monitoring in vivo biodistribution and the homing of EVs and their communication networks both in basal and pathological circumstances. This narrative review provides an overview of EC-EVs, trying to highlight their role as messengers of cell-cell interaction in vascular homeostasis and disease, and describes emerging applications of various imaging modalities for EVs visualization in vivo.