Investigating the consistency of extracellular vesicle production from breast cancer subtypes using CELLine adherent bioreactors

Deep autoencoder as an interpretable tool for Raman spectroscopy investigation of chemical and extracellular vesicle mixtures

Surface-enhanced Raman spectroscopy (SERS) is a powerful tool that provides valuable insight into the molecular contents of chemical and biological samples. However, interpreting Raman spectra from complex or dynamic datasets remains challenging, particularly for highly heterogeneous biological samples like extracellular vesicles (EVs). To overcome this, we developed a tunable and interpretable deep autoencoder for the analysis of several challenging Raman spectroscopy applications, including synthetic datasets, chemical mixtures, a chemical milling reaction, and mixtures of EVs. We compared the results with classical methods (PCA and UMAP) to demonstrate the superior performance of the proposed technique. Our method can handle small datasets, provide a high degree of generalization such that it can fill unknown gaps within spectral datasets, and even quantify relative ratios of cell line-derived EVs to fetal bovine serum-derived EVs within mixtures. This simple yet robust approach will greatly improve the analysis capabilities for many other Raman spectroscopy applications.

The tumour-derived extracellular vesicle proteome varies by endometrial cancer histology and is confounded by an obesogenic environment

Endometrial cancer, the most common gynaecological cancer worldwide, is closely linked to obesity and metabolic diseases, particularly in younger women. New circulating biomarkers have the potential to improve diagnosis and treatment selections, which could significantly improve outcomes. Our approach focuses on extracellular vesicle (EV) biomarker discovery by directly profiling the proteome of EVs enriched from frozen biobanked endometrial tumours. We analysed nine tissue samples to compare three clinical subgroups-low BMI (Body Mass Index) Endometrioid, high BMI Endometrioid, and Serous (any BMI)-identifying proteins related to histological subtype, BMI, and shared secreted proteins. Using collagenase digestion and size exclusion chromatography, we successfully enriched generous quantities of EVs (range 204.8-1291.0 µg protein: 1.38 × 1011-1.10 × 1012 particles), characterised by their size (∼150 nm), expression of EV markers (CD63/81), and proposed endometrial cancer markers (L1CAM, ANXA2). Mass spectrometry-based proteomic profiling identified 2075 proteins present in at least one of the 18 samples. Compared to cell lysates, EVs were successfully depleted for mitochondrial and blood proteins and enriched for common EV markers and large secreted proteins. Further analysis highlighted significant differences in EV protein profiles between the high BMI subgroup and others, underlining the impact of comorbidities on the EV secretome. Interestingly, proteins differentially abundant in tissue subgroups were largely not also differential in matched EVs. This research identified secreted proteins known to be involved in endometrial cancer pathophysiology and proposed novel diagnostic biomarkers (EIF6, MUC16, PROM1, SLC26A2).

Light-induced Extracellular Vesicle Adsorption

The role of extracellular vesicles (EVs) in human health and disease has garnered considerable attention over the past two decades. However, while several types of EVs are known to interact dynamically with the extracellular matrix and there is great potential value in producing high-fidelity EV micropatterns, there are currently no label-free, high-resolution, and tunable platform technologies with this capability. We introduce Light-induced Extracellular Vesicle Adsorption (LEVA) as a powerful solution to rapidly advance the study of matrix- and surface-bound EVs and other particles. The versatility of LEVA is demonstrated using commercial GFP-EV standards, EVs from glioblastoma bioreactors, and E. coli outer membrane vesicles (OMVs), with the resulting patterns used for single EV characterization, single cell migration on migrasome-mimetic trails, and OMV-mediated neutrophil swarming. LEVA will enable rapid advancements in the study of matrix- and surface-bound EVs and other particles, and should encourage researchers from many disciplines to create novel diagnostic, biomimetic, immunoengineering, and therapeutic screening assays.

Limiting Brownian Motion to Enhance Immunogold Phenotyping and Superimpose Optical and Non-Optical Single-EP Analyses

Optical and non-optical techniques propelled the field of single extracellular particle (EP) research through phenotypic and morphological analyses, revealing the similarities, differences, and co-isolation of EP subpopulations. Overcoming the challenges of optical and non-optical techniques motivates the use of orthogonal techniques while analyzing extracellular particles (EPs), which require varying concentrations and preparations. Herein, we introduce the nano-positioning matrix (NPMx) technique capable of superimposing optical and non-optical modalities for a single-EP orthogonal analysis. The NPMx technique is realized by ultraviolet-mediated micropatterning to reduce the stochasticity of Brownian motion. While providing a systematic orthogonal measurement of a single EP via total internal reflection fluorescence microscopy and transmission electron microscopy, the NPMx technique is compatible with low-yield samples and can be utilized for non-biased electrostatic capture and enhanced positive immunogold sorting. The success of the NPMx technique thus provides a novel platform by marrying already trusted optical and non-optical techniques at a single-EP resolution.

Engineered Extracellular Vesicles Derived from Dermal Fibroblasts Attenuate Inflammation in a Murine Model of Acute Lung Injury

Acute respiratory distress syndrome (ARDS) represents a significant burden to the healthcare system, with ≈200 000 cases diagnosed annually in the USA. ARDS patients suffer from severe refractory hypoxemia, alveolar-capillary barrier dysfunction, impaired surfactant function, and abnormal upregulation of inflammatory pathways that lead to intensive care unit admission, prolonged hospitalization, and increased disability-adjusted life years. Currently, there is no cure or FDA-approved therapy for ARDS. This work describes the implementation of engineered extracellular vesicle (eEV)-based nanocarriers for targeted nonviral delivery of anti-inflammatory payloads to the inflamed/injured lung. The results show the ability of surfactant protein A (SPA)-functionalized IL-4- and IL-10-loaded eEVs to promote intrapulmonary retention and reduce inflammation, both in vitro and in vivo. Significant attenuation is observed in tissue damage, proinflammatory cytokine secretion, macrophage activation, influx of protein-rich fluid, and neutrophil infiltration into the alveolar space as early as 6 h post-eEVs treatment. Additionally, metabolomics analyses show that eEV treatment causes significant changes in the metabolic profile of inflamed lungs, driving the secretion of key anti-inflammatory metabolites. Altogether, these results establish the potential of eEVs derived from dermal fibroblasts to reduce inflammation, tissue damage, and the prevalence/progression of injury during ARDS via nonviral delivery of anti-inflammatory genes/transcripts.

Delivery of mitochondria-containing extracellular vesicles to the BBB for ischemic stroke therapy

INTRODUCTION

Ischemic stroke-induced mitochondrial dysfunction in brain endothelial cells (BECs) leads to breakdown of the blood-brain barrier (BBB) causing long-term neurological dysfunction. Restoration of mitochondrial function in injured BECs is a promising therapeutic strategy to alleviate stroke-induced damage. Mounting evidence demonstrate that selected subsets of cell-derived extracellular vehicles (EVs), such as exosomes (EXOs) and microvesicles (MVs), contain functional mitochondrial components. Therefore, development of BEC-derived mitochondria-containing EVs for delivery to the BBB will (1) alleviate mitochondrial dysfunction and limit long-term neurological dysfunction in ischemic stroke and (2) provide an alternative therapeutic option for treating numerous other diseases associated with mitochondrial dysfunction.

AREA COVERED

This review will discuss (1) how EV subsets package different types of mitochondrial components during their biogenesis, (2) mechanisms of EV internalization and functional mitochondrial responses in the recipient cells, and (3) EV biodistribution and pharmacokinetics - key factors involved in the development of mitochondria-containing EVs as a novel BBB-targeted stroke therapy.

EXPERT OPINION

Mitochondria-containing MVs have demonstrated therapeutic benefits in ischemic stroke and other pathologies associated with mitochondrial dysfunction. Delivery of MV mitochondria to the BBB is expected to protect the BBB integrity and neurovascular unit post-stroke. MV mitochondria quality control, characterization, mechanistic understanding of its effects in vivo, safety and efficacy in different preclinical models, large-scale production, and establishment of regulatory guidelines are foreseeable milestones to harness the clinical potential of MV mitochondria delivery.