The cancer cell-derived extracellular vesicle glycocode in immunoevasion.

Recent evidence suggests that cancer cell-derived extracellular vesicles might facilitate immunoevasion. Glycans are known to play a key role in immunomodulation, especially when tethered to biological membranes. However, the extracellular vesicle glycocode in cancer immunoevasion remains a largely unexplored area with promising potential for new putative diagnostic and therapeutic applications.

Extracellular Vesicle and Lipoprotein Interactions.

Extracellular vesicles and lipoproteins are lipid-based biological nanoparticles that play important roles in (patho)physiology. Recent evidence suggests that extracellular vesicles and lipoproteins can interact to form functional complexes. Such complexes have been observed in biofluids from healthy human donors and in various in vitro disease models such as breast cancer and hepatitis C infection. Lipoprotein components can also form part of the biomolecular corona that surrounds extracellular vesicles and contributes to biological identity. Potential mechanisms and the functional relevance of extracellular vesicle-lipoprotein complexes remain poorly understood. This Review addresses the current knowledge of the extracellular vesicle-lipoprotein interface while drawing on pre-existing knowledge of liposome interactions with biological nanoparticles. There is an urgent need for further research on the lipoprotein-extracellular vesicle interface, which could return important mechanistic, therapeutic, and diagnostic findings.

Chemically-Induced Lipoprotein Breakdown for Improved Extracellular Vesicle Purification.

Extracellular vesicles (EVs) are nanosized biomolecular packages involved in intercellular communication. EVs are released by all cells, making them broadly applicable as therapeutic, diagnostic, and mechanistic components in (patho)physiology. Sample purity is critical for correctly attributing observed effects to EVs and for maximizing therapeutic and diagnostic performance. Lipoprotein contaminants represent a major challenge for sample purity. Lipoproteins are approximately six orders of magnitude more abundant in the blood circulation and overlap in size, shape, and density with EVs. This study represents the first example of an EV purification method based on the chemically-induced breakdown of lipoproteins. Specifically, a styrene-maleic acid (SMA) copolymer is used to selectively breakdown lipoproteins, enabling subsequent size-based separation of the breakdown products from plasma EVs. The use of the polymer followed by tangential flow filtration or size-exclusion chromatography results in improved EV yield, preservation of EV morphology, increased EV markers, and reduced contaminant markers. SMA-based EV purification enables improved fluorescent labeling, reduces interactions with macrophages, and enhances accuracy, sensitivity, and specificity to detect EV biomarkers, indicating benefits for various downstream applications. In conclusion, SMA is a simple and effective method to improve the purity and yield of plasma-derived EVs, which favorably impacts downstream applications.

Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice.

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1ß), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Glycan Node Analysis Detects Varying Glycosaminoglycan Levels in Melanoma-Derived Extracellular Vesicles.

Extracellular vesicles (EVs) play important roles in (patho)physiological processes by mediating cell communication. Although EVs contain glycans and glycosaminoglycans (GAGs), these biomolecules have been overlooked due to technical challenges in comprehensive glycome analysis coupled with EV isolation. Conventional mass spectrometry (MS)-based methods are restricted to the assessment of N-linked glycans. Therefore, methods to comprehensively analyze all glyco-polymer classes on EVs are urgently needed. In this study, tangential flow filtration-based EV isolation was coupled with glycan node analysis (GNA) as an innovative and robust approach to characterize most major glyco-polymer features of EVs. GNA is a molecularly bottom-up gas chromatography-MS technique that provides unique information that is unobtainable with conventional methods. The results indicate that GNA can identify EV-associated glyco-polymers that would remain undetected with conventional MS methods. Specifically, predictions based on GNA identified a GAG (hyaluronan) with varying abundance on EVs from two different melanoma cell lines. Enzyme-linked immunosorbent assays and enzymatic stripping protocols confirmed the differential abundance of EV-associated hyaluronan. These results lay the framework to explore GNA as a tool to assess major glycan classes on EVs, unveiling the EV glycocode and its biological functions.

Extracellular vesicle glucose transporter-1 and glycan features in monocyte-endothelial inflammatory interactions.

Monocyte-induced endothelial cell inflammation is associated with multiple pathological conditions, and extracellular vesicles (EVs) are essential nanosized components of intercellular communication. EVs derived from endotoxin-stimulated monocytes were previously shown to carry pro-inflammatory proteins and RNAs. The role of glucose transporter-1 (GLUT-1) and glycan features in monocyte-derived EV-induced endothelial cell inflammation remains largely unexplored. This study demonstrates that EVs derived from endotoxin-stimulated monocytes activate inflammatory pathways in endothelial cells, which are partially attributed to GLUT-1. Alterations in glycan features and increased levels of GLUT-1 were observed in EVs derived from endotoxin-stimulated monocytes. Notably, inhibition of EV-associated GLUT-1, through the use of fasentin, suppressed EV-induced inflammatory cytokines in recipient endothelial cells.

Extracellular vesicles for treatment of solid organ ischemia-reperfusion injury.

As the incidence of ischemia-reperfusion (I-R) injury has substantially increased, there is a pressing need to develop effective strategies to treat this global health issue. I-R injury can affect all organs and is associated with high morbidity and mortality rates. Pathological settings such as myocardial infarction, stroke, hemorrhagic shock, and solid organ transplant are particularly prone to cause I-R injury. Ischemia (hypoxia) and/or reperfusion (reoxygenation) induces various forms of cellular and structural damage. A major cause of damage is local inflammatory responses, which may spread to produce more advanced systemic inflammation. Management of I-R injury relies primarily on supportive measures, as specific treatment strategies are lacking. Extracellular vesicles (EVs) are cell-secreted nano-scale structures containing various biomolecules involved in cell communication and multiple physiological processes. EVs derived from certain cell types have been shown to exhibit anti-inflammatory, antioxidant, and angiogenic properties. This review provides an overview of EV-based therapeutics for I-R injury in kidneys, liver, heart, lungs, and brain. Additionally, the mechanisms by which EVs protect against I-R injury are discussed. Promising preclinical findings highlight the potential clinical use of EVs for I-R injury.

Adipose-Derived Biogenic Nanoparticles for Suppression of Inflammation.

Extracellular vesicles secreted from adipose-derived mesenchymal stem cells (ADSCs) have therapeutic effects in inflammatory diseases. However, production of extracellular vesicles (EVs) from ADSCs is costly, inefficient, and time consuming. The anti-inflammatory properties of adipose tissue-derived EVs and other biogenic nanoparticles have not been explored. In this study, biogenic nanoparticles are obtained directly from lipoaspirate, an easily accessible and abundant source of biological material. Compared to ADSC-EVs, lipoaspirate nanoparticles (Lipo-NPs) take less time to process (hours compared to months) and cost less to produce (clinical-grade cell culture facilities are not required). The physicochemical characteristics and anti-inflammatory properties of Lipo-NPs are evaluated and compared to those of patient-matched ADSC-EVs. Moreover, guanabenz loading in Lipo-NPs is evaluated for enhanced anti-inflammatory effects. Apolipoprotein E and glycerolipids are enriched in Lipo-NPs compared to ADSC-EVs. Additionally, the uptake of Lipo-NPs in hepatocytes and macrophages is higher. Lipo-NPs and ADSC-EVs have comparable protective and anti-inflammatory effects. Specifically, Lipo-NPs reduce toll-like receptor 4-induced secretion of inflammatory cytokines in macrophages. Guanabenz-loaded Lipo-NPs further suppress inflammatory pathways, suggesting that this combination therapy can have promising applications for inflammatory diseases.

Brain metastases-derived extracellular vesicles induce binding and aggregation of low-density lipoprotein.

BACKGROUND: Cancer cell-derived extracellular vesicles (EVs) have previously been shown to contribute to pre-metastatic niche formation. Specifically, aggressive tumors secrete pro-metastatic EVs that travel in the circulation to distant organs to modulate the microenvironment for future metastatic spread. Previous studies have focused on the interface between pro-metastatic EVs and epithelial/endothelial cells in the pre-metastatic niche. However, EV interactions with circulating components such as low-density lipoprotein (LDL) have been overlooked. RESULTS: This study demonstrates that EVs derived from brain metastases cells (Br-EVs) and corresponding regular cancer cells (Reg-EVs) display different interactions with LDL. Specifically, Br-EVs trigger LDL aggregation, and the presence of LDL accelerates Br-EV uptake by monocytes, which are key components in the brain metastatic niche. CONCLUSIONS: Collectively, these data are the first to demonstrate that pro-metastatic EVs display distinct interactions with LDL, which impacts monocyte internalization of EVs.

Organotropic drug delivery: Synthetic nanoparticles and extracellular vesicles.

Most clinically approved drugs (primarily small molecules or antibodies) are rapidly cleared from circulation and distribute throughout the body. As a consequence, only a small portion of the dose accumulates at the target site, leading to low efficacy and adverse side effects. Therefore, new delivery strategies are necessary to increase organ and tissue-specific delivery of therapeutic agents. Nanoparticles provide a promising approach for prolonging the circulation time and improving the biodistribution of drugs. However, nanoparticles display several limitations, such as clearance by the immune systems and impaired diffusion in the tissue microenvironment. To overcome common nanoparticle limitations various functionalization and targeting strategies have been proposed. This review will discuss synthetic nanoparticle and extracellular vesicle delivery strategies that exploit organ-specific features to enhance drug accumulation at the target site.

A Liposome Encapsulated Ruthenium Polypyridine Complex as a Theranostic Platform for Triple-Negative Breast Cancer.

Ruthenium coordination complexes have the potential to serve as novel theranostic agents for cancer. However, a major limitation in their clinical implementation is effective tumor accumulation. In this study, we have developed a liposome-based theranostic nanodelivery system for [Ru(phen)2dppz](ClO4)2 (Lipo-Ru). This ruthenium polypyridine complex emits a strong fluorescent signal when incorporated in the hydrophobic lipid bilayer of the delivery vehicle or in the DNA helix, enabling visualization of the therapeutic agent in tumor tissues. Incubation of MDA-MB-231 breast cancer cells with Lipo-Ru induced double-strand DNA breaks and triggers apoptosis. In a mouse model of triple-negative breast cancer, treatment with Lipo-Ru dramatically reduced tumor growth. Biodistribution studies of Lipo-Ru revealed that more than 20% of the injected dose accumulated in the tumor. These results suggest that Lipo-Ru could serve as a promising theranostic platform for cancer.

Enzyme-responsive multistage vector for drug delivery to tumor tissue.

Various nanodelivery systems have been designed to release therapeutic agents upon contact with specific enzymes. However, enzyme-triggered release typically takes place in the tissue interstitium, thereby resulting in the extracellular delivery of drugs. Here, we have designed an enzyme-stimulated multistage vector (ESMSV), which enables stimulus-triggered release of drug-encapsulated nanoparticles from a microparticle. Specifically, polymeric nanoparticles with a surface matrix metalloproteinase-2 (MMP2) peptide substrate were conjugated to the surface of porous silicon microparticles. In the presence of MMP2, the polymeric nanoparticles were released into the tumor interstitium. This platform can be used to attain triggered drug release, while simultaneously facilitating the cellular internalization of drugs. The results indicate that nanoparticle release was MMP2-specific and resulted in improved intracellular uptake of hydrophobic agents in the presence of MMP2. Furthermore, in a mouse model of melanoma lung metastasis, systemic delivery of ESMSVs caused a substantial increase in intracellular accumulation of agents in cancer cells in comparison to delivery with non-stimulus-responsive particles.

A pyruvate decarboxylase-mediated therapeutic strategy for mimicking yeast metabolism in cancer cells.

Cancer cells have high rates of glycolysis and lactic acid fermentation in order to fuel accelerated rates of cell division (Warburg effect). Here, we present a strategy for merging cancer and yeast metabolism to remove pyruvate, a key intermediate of cancer cell metabolism, and produce the toxic compound acetaldehyde. This approach was achieved by administering the yeast enzyme pyruvate decarboxylase to triple negative breast cancer cells. To overcome the challenges of protein delivery, a nanoparticle-based system consisting of cationic lipids and porous silicon were employed to obtain efficient intracellular uptake. The results demonstrate that the enzyme therapy decreases cancer cell viability through production of acetaldehyde and reduction of lactic acid fermentation.

Protective effects of intestinal trefoil factor (ITF) on gastric mucosal epithelium through activation of extracellular signal-regulated kinase 1/2 (ERK1/2).

The rapid repair of gastric mucosa is critical upon exposure to injurious agents. Intestinal trefoil factor (ITF) is a member of the trefoil factor family domain peptides, which play an important role in the cytoprotection of gastric epithelium. However, the underlying molecular mechanisms that are responsible for ITF-induced gastric epithelial repair remain unclear. In the present study, we demonstrate that ITF enhances the proliferation and migration of GES-1 gastric endothelial cells in a dose- and time-dependent manner through the activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, the ITF-mediated protection of GES-1 cells from a NS398 (nonsteroidal anti-inflammatory drug) was dependent on the ERK1/2 signaling pathway. Taken together, the results provide a mechanistic explanation for ITF-mediated protection of gastric epithelial mucosa cells, suggesting that activation of the ERK1/2 signaling pathway may provide a new therapeutic strategy for repairing gastric injury.

Polyarginine induces an antitumor immune response through binding to toll-like receptor 4.

A novel function of polyarginine as an activator of the immune system is reported. Single-molecule fluorescence imaging and single-molecule force measurements demonstrate that polyarginine binds specifically to the toll-like receptor 4 (TLR4), inducing receptor dimerization and activation. Moreover, polyarginine induced immune activation inhibits tumor growth. These results suggest the potential use of polyarginine for cancer immunotherapy.

The impact of lubricants on the precision lapping process.

The impact of lubricants on pole-tip recession and surface morphology of hard disk drive heads in the precision lapping process was investigated with atomic force microscopy, scanning electron microscopy, and auger electron spectroscopy. In particular, the effects of deionized water, hydrocarbon oil, ethanediol, isopropanol, and ethanol lubricants were evaluated. The results reveal that proper selection of lubricant is critical for achieving optimal performance in the lapping process. A mixture of 68% hydrocarbon oil, 30% isopropanol, and 2% octadecenoic acid was found to yield the most favorable results, displaying a writer shield recession, first shield of reader recession, and surface roughness of 0.423, 0.581, and 0.242 nm, respectively.

Mechanistic features of nanodiamonds in the lapping of magnetic heads.

Nanodiamonds, which are the main components of slurry in the precision lapping process of magnetic heads, play an important role in surface quality. This paper studies the mechanistic features of nanodiamond embedment into a Sn plate in the lapping process. This is the first study to develop mathematical models for nanodiamond embedment. Such models can predict the optimum parameters for particle embedment. From the modeling calculations, the embedded pressure satisfies p 0 = (3/2) · (W/πa (2)) and the indentation depth satisfies δ = k1√P/HV. Calculation results reveal that the largest embedded pressure is 731.48 GPa and the critical indentation depth δ is 7 nm. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and Auger electron spectroscopy (AES) were used to carry out surface quality detection and analysis of the disk head. Both the formation of black spots on the surface and the removal rate have an important correlation with the size of nanodiamonds. The results demonstrate that an improved removal rate (21 nm · min(-1)) can be obtained with 100 nm diamonds embedded in the plate.

Evaluation of anticancer activity of celastrol liposomes in prostate cancer cells.

CONTEXT: Celastrol, a natural compound derived from the herb Tripterygium wilfordii, is known to have anticancer activity, but is not soluble in water. OBJECTIVE: Formation of celastrol liposomes, to avoid the use of toxic solubilising agents. MATERIALS AND METHODS: Two different formulations of PEGylated celastrol liposomes were fabricated. Liposomal characteristics and serum stability were determined using dynamic light scattering. Drug entrapment efficacy and drug release were measured spectrophotometrically. Cellular internalisation and anticancer activity was measured in prostate cancer cells. RESULTS: Liposomal celastrol displayed efficient serum stability, cellular internalisation and anticancer activity, comparable to that of the free drug reconstituted in dimethyl sulfoxide. DISCUSSION AND CONCLUSION: Liposomal celastrol can decrease the viability of prostate cancer cells, while eliminating the need for toxic solubilising agents.

Immunogenicity of Extracellular Vesicles.

Extracellular vesicles (EVs) are promising next-generation therapeutics and drug delivery systems due to demonstrated safety and efficacy in preclinical models and early-stage clinical trials. There is an urgent need to address the immunogenicity of EVs (beyond the apparent lack of immunotoxicity) to advance clinical development. To date, few studies have assessed unintended immunological recognition of EVs. An in-depth understanding of EV-induced immunogenicity and clearance is necessary to develop effective therapeutic strategies, including approaches to mitigate immunological recognition when undesired. This article summarizes various factors involved in the potential immunogenicity of EVs and strategies to reduce immunological recognition for improved therapeutic benefit.