Isolation of exosomes from serum of patients with lung cancer: a comparison of the ultra-high speed centrifugation and precipitation methods

Small extracellular vesicles-mediated cellular interactions between tumor cells and tumor-associated macrophages: Implication for immunotherapy

The tumor microenvironment consists of cancer cells and various stromal cells, including macrophages, which exhibit diverse phenotypes with either pro-inflammatory (M1) or anti-inflammatory (M2) effects. The interaction between cancer cells and macrophages plays a crucial role in tumor progression. Small extracellular vesicles (sEVs), which facilitate intercellular communication, are known to play a vital role in this process. This review provides a comprehensive summary of how sEVs derived from cancer cells, containing miRNAs, lncRNAs, proteins, and lipids, can influence macrophage polarization. Additionally, we discuss the impact of macrophage-secreted sEVs on tumor malignant transformation, including effects on proliferation, metastasis, angiogenesis, chemoresistance, and immune escape. Furthermore, we address the therapeutic advancements and current challenges associated with macrophage-associated sEVs, along with potential solutions.

A method for extraction of exosomes from breast tumour cells and characterisation by transmission electron microscopy

Exosomes can not only be used as markers of tumour metastasis but also be used for noninvasive diagnosis of clinical diseases, which holds significant medical research value. Observing the morphology and distribution of exosomes using transmission electron microscopy (TEM) is highly significant. In this study, we use breast tumour cell (MDA-MB-231) exosomes as a representative sample and focus on the extraction and purification of exosomes, as well as the investigation of optimal conditions for the observation of exosomes using TEM. Through comparative tests, we obtained the optimal dilution concentration and staining method for TEM of exosomes, the best dilution concentration is 100 times, the best negative staining time is 1.5 min. Western blotting and scanning electron microscopy (SEM) confirmed the presence of exosome. The particle size experiment shows that the size of exosomes is mainly distributed between 60 nm and 150 nm. This method provides a reference for TEM sample preparation of subcellular structures and small molecular biomaterials other than exosomes.

Exosomes: a potential diagnostic and treatment modality in the quest for counteracting cancer

BACKGROUND

Exosomes are nanosized bio vesicles formed when multivesicular bodies and the plasma membrane merge and discharge into bodily fluids. They are well recognized for facilitating intercellular communication by transporting numerous biomolecules, including DNA, RNAs, proteins, and lipids, and have been implicated in varied diseases including cancer. Exosomes may be altered to transport a variety of therapeutic payloads, including as short interfering RNAs, antisense oligonucleotides, chemotherapeutic drugs, and immunological modulators, and can be directed to a specific target. Exosomes also possess the potential to act as a diagnostic biomarker in cancer, in addition to their therapeutic potential.

CONCLUSION

In this review, the physiological roles played by exosomes were summarized along with their biogenesis process. Different isolation techniques of exosomes including centrifugation-based, size-based, and polymer precipitation-based techniques have also been described in detail with a special focus on cancer therapeutic applications. The review also shed light on techniques of incubation of drugs with exosomes and their characterization methods covering the most advanced techniques. Myriad applications of exosomes in cancer as diagnostic biomarkers, drug delivery carriers, and chemoresistance-related issues have been discussed at length. Furthermore, a brief overview of exosome-based anti-cancer vaccines and a few prominent challenges concerning exosomal delivery have been concluded at the end.

Mesenchymal Stem Cells and Exosomes: A Novel Therapeutic Approach for Corneal Diseases

The cornea, with its delicate structure, is vulnerable to damage from physical, chemical, and genetic factors. Corneal transplantation, including penetrating and lamellar keratoplasties, can restore the functions of the cornea in cases of severe damage. However, the process of corneal transplantation presents considerable obstacles, including a shortage of available donors, the risk of severe graft rejection, and potentially life-threatening complications. Over the past few decades, mesenchymal stem cell (MSC) therapy has become a novel alternative approach to corneal regeneration. Numerous studies have demonstrated the potential of MSCs to differentiate into different corneal cell types, such as keratocytes, epithelial cells, and endothelial cells. MSCs are considered a suitable candidate for corneal regeneration because of their promising therapeutic perspective and beneficial properties. MSCs compromise unique immunomodulation, anti-angiogenesis, and anti-inflammatory properties and secrete various growth factors, thus promoting corneal reconstruction. These effects in corneal engineering are mediated by MSCs differentiating into different lineages and paracrine action via exosomes. Early studies have proven the roles of MSC-derived exosomes in corneal regeneration by reducing inflammation, inhibiting neovascularization, and angiogenesis, and by promoting cell proliferation. This review highlights the contribution of MSCs and MSC-derived exosomes, their current usage status to overcome corneal disease, and their potential to restore different corneal layers as novel therapeutic agents. It also discusses feasible future possibilities, applications, challenges, and opportunities for future research in this field.

A review on comparative studies addressing exosome isolation methods from body fluids

Exosomes emerged as valuable sources of disease biomarkers and new therapeutic tools. However, extracellular vesicles isolation with exosome-like characteristics from certain biofluids is still challenging which can limit their potential use in clinical settings. While ultracentrifugation-based procedures are the gold standard for exosome isolation from cell cultures, no unique and standardized method for exosome isolation from distinct body fluids exists. The complexity, specific composition, and physical properties of each biofluid constitute a technical barrier to obtain reproducible and pure exosome preparations, demanding a detailed characterization of both exosome isolation and characterization methods. Moreover, some isolation procedures can affect downstream proteomic or RNA profiling analysis. This review compiles and discussed a set of comparative studies addressing distinct exosome isolation methods from human biofluids, including cerebrospinal fluid, plasma, serum, saliva, and urine, also focusing on body fluid specific challenges, physical properties, and other potential variation sources. This summarized information will facilitate the choice of exosome isolation methods, based on the type of biological samples available, and hopefully encourage the use of exosomes in translational and clinical research.

Innovative model of surface-enhanced Raman spectroscopy for exosomes identification: An approach for the diagnosis of hepatocellular carcinoma

BACKGROUND

The current hepatocellular carcinoma (HCC) diagnostic approaches lack adequate sensitivity and specificity. So, this study was performed to develop an innovative model of surface-enhanced Raman spectroscopy (SERS) that can detect HCC patients by identifying the circulating tumor-derived exosomes.

METHODOLOGY

Sixty participants, including normal controls, hepatitis C virus (HCV)-infected patients, and HCV-associated HCC patients, had their whole blood samples and exosomes separated from these samples analyzed using Raman spectroscopy (RS). A revolutionary model of SERS, based on an innovative glass and nano-gold, was designed to directly identify exosomes. Its measurements were simulated by Comsol Multiphysics (5.6).

RESULTS

The RS examination of the whole blood samples revealed no Raman peaks. Yet, the isolated exosomes from these samples generated Raman peaks at 400 and 1000 cm^-1 wavenumbers in the HCV group. A Raman shift was detected in HCC patients at 812, 852, and 878 cm^-1 wavenumbers with intensity ratios of 120, 130, and 60, respectively. The RS had a sensitivity and specificity of 95 % and 100 %, respectively, for detecting HCC. However, the newly-designed SERS was able to identify the HCC-derived exosomes, at 812 and 878 cm^-1 wavenumbers, with boosted intensity ratios of 9*10⁶ and 4*10⁶, respectively, in the whole blood samples.

CONCLUSION

The newly-developed SERS model has the potential to detect HCC patients through recognizing the tumor-derived exosomes non-invasively, with high accuracy, and without the need for laborious exosomal separation. Nonetheless, bringing this technology into the clinic demands the establishment of spectral databases and their validation using the current gold standards.

Exploring Purification Methods of Exosomes from Different Biological Samples

Objective

Exosomes were extracted from a variety of biological samples using several different purification processes, and our goal was to determine which method and sample were the most effective for exosome extraction.

Methods

We used ExoQuick-TC combined with ultrafiltration to separate and purify exosomes from the supernatant of gastric cancer cells, while we used the ExoQuick kit and ultracentrifugation to purify exosomes from human serum samples. Furthermore, exosomes were isolated and purified from human urine samples by diafiltration and from postparturition human breast milk samples by the filtration-polyethylene glycol precipitation method. The isolated exosomes were morphologically analyzed using a transmission electron microscope, the particle size was measured by NanoSight, and the protein content was analyzed by western blotting.

Results

The isolated exosomes showed an obvious cup holder shape, with a clear outline and typical exosome morphological characteristics. The sizes of exosomes derived from gastric cancer cell supernatant, serum, urine, and milk were 65.8 ± 26.9 nm, 87.6 ± 50.9 nm, 197.5 ± 55.2 nm, and 184.1 ± 68.7 nm, respectively. Western blot results showed that CD9 and TSG101 on the exosomes were expressed to varying degrees based on the exosome source. Exosome abundance was higher in the serum, urine, and breast milk than in the supernatant. It is suggested that its exosomes can be extracted to obtain an excellent potential biological source of exosomes.

Conclusion

In this study, the extraction and separation methods of foreign bodies from different biological samples were obtained, and it was found that human breast milk was a potential excellent material for administration because of its high abundance.

CARDIOPULMONARY BYPASS-DERIVED PLASMA EXOSOMAL HMGB1 CONTRIBUTES TO ALVEOLAR EPITHELIAL CELL NECROPTOSIS VIA mtDNA/CGAS/STING PATHWAY

ABSTRACT

Our previous study confirmed that cardiopulmonary bypass (CPB) leads to acute lung injury (ALI) via inducing high-mobility group box 1 (HMGB1) release. Recent research showed that HMGB1 promotes pulmonary injury mainly via exosomes transport. Currently, alveolar epithelial cell (AEC) necroptosis has been demonstrated to be involved in ALI. However, it is unknown whether exosomal inflammatory cytokine HMGB1 promotes ALI by inducing AEC necroptosis, and its underlying mechanisms remain elusive. Here, a prospective cohort study was carried out, in which plasma samples from 21 CPB patients were isolated at four specific time points: pre-CPB, 2, 12, and 24 h after initiation of CPB. Plasma exosomes were extracted via ultra-high-speed centrifugation and cocultured with AEC cell line-A549 cells at increasing concentrations of 50, 100, and 150 μg/mL. Then, HMGB1 antagonist-Box A and mtDNA deficiency ethidium bromide (EtBr) were applied to explore the underlying role of exosomal HMGB1 and cytoplasm mitochondrial DNA in AEC. Western blot analysis showed that plasma exosomal HMGB1 expression gradually increased and peaked at 24 h after CPB. Twenty-four-hour treatment of CPB-derived exosomes at 150 μg/mL for 24 h could induce necroptosis by promoting mitochondrial fission and further elevating cytoplasm mtDNA levels in A549 cells, which was successfully blocked by Box A or EtBr. Most importantly, EtBr significantly inhibited cytoplasm mtDNA downstream guanosine monophosphate (GMP)-AMP synthase (cGAS)/stimulator of interferon gene (STING) signal pathway. Collectively, these data demonstrate that CPB-derived plasma exosomal HMGB1 contributes to AEC necroptosis through the mtDNA/cGAS/STING pathway.

Integrated microfluidic-SERS for exosome biomarker profiling and osteosarcoma diagnosis

Osteosarcoma is one of the most frequent primary sarcoma of bone among adolescents. Early diagnosis of osteosarcoma is the key factor to achieve high survival rate of patients. Nevertheless, traditional histological biopsy is highly invasive and associated with the risk of arousing tumor spread. Herein, we develop a method integrating microfluidics and surface-enhanced Raman spectroscopy (SERS) to isolate plasma-derived exosomes and profile multiple exosomal biomarkers for the diagnosis of osteosarcoma. The method showed highly efficient isolation of exosomes directly from human plasma and can profile exosomes based on protein biomarkers, with the detection limit down to 2 exosomes per μL. The whole assay can be performed in 5 h and only consumed 50 μL of plasma for one analysis. With the method, we analyzed the level of three protein biomarkers, i.e., CD63, vimentin (VIM) and epithelial cell adhesion molecule (EpCAM), on plasma-derived exosomes from 20 osteosarcoma patients and 20 heathy controls. Significantly higher levels of CD63, VIM and EpCAM were observed on plasma exosomes from the osteosarcoma patients compared to the healthy controls. Based on the level of the exosomal biomarkers, a classification model was built for the rapid diagnosis of osteosarcoma, with the sensitivity, specificity and accuracy of 100%, 90% and 95%, respectively. The proposed method does not require complex operations nor expensive equipment, and has great promise in clinical diagnosis of cancer as a liquid biopsy technique.

Mesenchymal Stem Cell-Derived Exosomes as a Novel Strategy for the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) has been reported to be the most prevalent contributor to low back pain, posing a significant strain on the healthcare systems on a global scale. Currently, there are no approved therapies available for the prevention of the progressive degeneration of intervertebral disc (IVD); however, emerging regenerative strategies that aim to restore the normal structure of the disc have been fundamentally promising. In the last decade, mesenchymal stem cells (MSCs) have received a significant deal of interest for the treatment of IVDD due to their differentiation potential, immunoregulatory capabilities, and capability to be cultured and regulated in a favorable environment. Recent investigations show that the pleiotropic impacts of MSCs are regulated by the production of soluble paracrine factors. Exosomes play an important role in regulating such effects. In this review, we have summarized the current treatments for disc degenerative diseases and their limitations and highlighted the therapeutic role and its underlying mechanism of MSC-derived exosomes in IVDD, as well as the possible future developments for exosomes.

Research progress on exosomal proteins as diagnostic markers of gastric cancer (review article)

Gastric cancer (GC) is one of the most common types of tumors and the most common cause of cancer mortality worldwide. The diagnosis of GC is critical to its prevention and treatment. Available tumor markers are the crucial step for GC diagnosis. Recent studies have shown that proteins in exosomes are potential diagnostic and prognostic markers for GC. Exosomes, secreted by cells, are cup-shaped with a diameter of 30–150 nm under the electron microscope. They are also surrounded by lipid bilayers and are widely found in various body fluids. Exosomes contain proteins, lipids and nucleic acid. The examination of exosomal proteins has the advantages of quickness, easy sampling, and low pain and cost, as compared with the routine inspection method of GC, which may lead to marked developments in GC diagnosis. This article summarized the exosomal proteins with a diagnostic and prognostic potential in GC, as well as exosomal proteins involved in GC progression.

Recent advances in biological detection with rolling circle amplification: design strategy, biosensing mechanism, and practical applications

Rolling circle amplification (RCA) is a simple and isothermal DNA amplification technique that is used to generate thousands of repeating DNA sequences using circular templates under the catalysis of DNA polymerase.