The Relation Between Extracellular Vesicles Released From Red Blood Cells, Their Cargo, and the Clearance by Macrophages

Diagnostic and prognostic roles of endothelial- and platelet-derived extracellular vesicles in cardiovascular diseases

Extracellular vesicles (EVs) are membrane-bound structures released by all cell types. They play a critical role in intercellular communication by transferring their cargo, comprising proteins, lipids, metabolites, RNAs, miRNAs, and DNA fragments, to recipient cells. This transfer influences gene expression, signaling pathways, and cellular behavior. Due to their ability to alter the physiology of recipient cells, EVs hold significant therapeutic potential. Additionally, EVs are implicated in various physiological and pathological processes, including immune regulation, cancer progression, and cardiovascular diseases. EVs have been detected in many biological fluids, such as peripheral blood, saliva, urine, cerebrospinal fluid, and breast milk. The cargo of EVs dynamically reflects the physiological and pathological state of their parent cells, making them promising candidates for liquid biopsies in various clinical conditions. Specifically, different EV subtypes in cardiovascular diseases have been studied, with both endothelial and platelet-derived EVs playing significant roles in cardiovascular pathologies. This review focuses on the diagnostic and prognostic potential of endothelial and platelet-derived EVs in cardiovascular diseases, highlighting the role of EV subpopulations.

Nanoengineered Endocytic Biomaterials for Stem Cell Therapy

Stem cells, ideal for the tissue repair and regeneration, possess extraordinary capabilities of multidirectional differentiation and self‐renewal. However, the limited spontaneous differentiation potential makes it challenging to harness them for tissue repair without external intervention. Although conventional approaches using biomolecules, small organic molecules, and ions have shown specific and effective functions, they face challenges such as in vivo diffusion and degradation, poor internalization, and side effects on adjacent cells. Nanoengineered biomaterials offer a solution by solidifying and nanosizing these soluble regulating molecules and ions, facilitating their uptake by stem cells. Once inside lysosomes, these nanoparticles release their contents in a controlled “molecule or ion storm,” efficiently altering the intracellular biological and chemical microenvironment to tune the differentiation of stem cells. This newly emerged approach for regulating stem cell fate has attracted much attention in recent years. This method has shown promising results and is poised to enhance clinical stem cell therapy. This review provides an overview of the design principles for nanoengineered biomaterials, discusses the categories and characteristics of nanoparticles, summarizes the application of nanoparticles in tissue repair and regeneration, and discusses the direction of nanoparticle‐enhanced stem cell therapy and prospects for its clinical application in regenerative medicine.

Exosomal miR-4516 derived from ovarian cancer stem cells enhanced cisplatin tolerance in ovarian cancer by inhibiting GAS7

Ovarian cancer (OC) is a devastating disease for women, with chemotherapy resistance taking the lead. Cisplatin has been the first-line therapy for OC for a long time. However, the resistance of OC to cisplatin is an important impediment to its efficacy. Mounting studies showed that ovarian cancer stem cells (OCSCs) affected chemotherapy resistance by secreting exosomes. MicroRNAs (miRNAs) play important roles in exosomes secreted by OCSCs. Here, through the analysis of GEO database (GSE107155) combined with RT-qPCR of OC-related cells/clinical tissues, it was found that hsa-miR-4516 (miR-4516) was significantly up-regulated in OCSCs. Then, OCSCs-derived exosomes were isolated and identified, and it was observed the influence of exosomes on the chemoresistance in SKOV3/cisplatin (SKOV3/DDP) cells. These results manifested that OCSCs-mediated exosomes facilitated the chemoresistance of SKOV3/DDP cells by delivering miR-4516 into them. Growth arrest-specific 7 (GAS7), a downstream target of miR-4516, was determined by bioinformatics prediction combined with molecular biological detection. Next, we up-regulated GAS7 expression and discovered that the promotion of chemoresistance in SKOV3/DDP cells by OCSCs-derived exosomes was significantly impaired. Finally, the mice tumor model of SKOV3/DDP cells was built to estimate the effect of GAS7 over-expression on OC growth. The results showed that GAS7 inhibited the chemoresistance of OC in vivo. In conclusion, our experiments suggested that OCSCs-derived exosomes enhanced OC cisplatin resistance by suppressing GAS7 through the delivery of miR-4516. This study provides a possible target for the treatment of OC DDP resistance.

Extracellular Vesicles in the Repair of Bone and Cartilage Injury: From Macro‐Delivery to Micro‐Modification

Extracellular vesicles (EVs) are intermediaries in intercellular signal transmission and material exchange and have attracted significant attention from researchers in bone and cartilage repair. These nanoscale vesicles hold immense potential in facilitating bone and cartilage repair and regeneration by regulating the microenvironment at an injury site. However, their in vivo utilization is limited by their self‐clearance and random distribution. Therefore, various delivery platforms have been developed to improve EV targeting and retention rates in target organs while achieving a controlled release of EVs. Additionally, engineering modification of EVs has been proposed to effectively enhance EVs' intrinsic targeting and drug‐loading abilities and further improve their therapeutic effects on bone and cartilage injuries. This review aims to introduce the biogenesis of EVs and their regulatory mechanisms in the microenvironment of bone and cartilage injuries and comprehensively discuss the application of EV‐delivery platforms of different materials and various EV engineering modification methods in treating bone and cartilage injuries. The review's findings can help advance EV research and develop new strategies for improving the therapy of bone and cartilage injuries.

Acidification of blood plasma facilitates the separation and analysis of extracellular vesicles

BACKGROUND

Blood plasma is available with minimal invasive sampling, it has significant diagnostic utility, and it is a valuable source of extracellular vesicles (EVs). Nevertheless, rich protein content, the presence of lipoproteins (LPs) that share similar biophysical properties, and relatively low abundance of EVs, especially those of rare subpopulations, make any downstream application a very challenging task. The growing evidence of the intricate surface interactome of EVs, and the association of EVs with LPs, impose further challenges during EV purification, detection, and biomarker analyses.

OBJECTIVES

In this study, we tackled the fundamental issues of plasma EV yield and LP co-isolation and their implications in the subsequent marker analyses.

METHODS

Moderate acidification of plasma was combined with size exclusion chromatography (SEC) and/or differential centrifugation (DC) to disrupt LPs and improve recovery of EVs and their subsequent detection by immunoassays and single-particle analysis methods.

RESULTS

Our results demonstrate a surprisingly efficient enrichment of EVs (up to 3.3-fold higher than at pH 7) and partial depletion of LPs (up to 61.2%). Acidification of blood plasma samples enabled a quick single-step isoelectric precipitation of up to 20.4% of EVs directly from plasma, upon short low-speed centrifugation.

CONCLUSION

Thus, acidification holds potential as a simple and inexpensive methodological step, which improves the efficacy of plasma EV enrichment and may have implications in future biomarker discoveries.

Extracellular Vesicles in Tissue Engineering: Biology and Engineered Strategy

Extracellular vesicles (EVs), acting as an important ingredient of intercellular communication through paracrine actions, have gained tremendous attention in the field of tissue engineering (TE). Moreover, these nanosized extracellular particles (30-140 nm) can be incorporated into biomaterials according to different principles to facilitate signal delivery in various regenerative processes directly or indirectly. Bioactive biomaterials as the carrier will extend the retention time and realize the controlled release of EVs, which further enhance their therapeutic efficiency in tissue regeneration. Herein, the basic biological characteristics of EVs are first introduced, and then their outstanding performance in exerting direct impacts on target cells in tissue regeneration as well as indirect effects on promoting angiogenesis and regulating the immune environment, due to specific functional components of EVs (nucleic acid, protein, lipid, etc.), is emphasized. Furthermore, different design ideas for suitable EV-loaded biomaterials are also demonstrated. In the end, this review also highlights the engineered strategies, which aim at solving the problems related to natural EVs such as highly heterogeneous functions, inadequate tissue targeting capabilities, insufficient yield and scalability, etc., thus promoting the therapeutic pertinence and clinical potential of EV-based approaches in TE.