Blood exosomes-based targeted delivery of cPLA2 siRNA and metformin to modulate glioblastoma energy metabolism for tailoring personalized therapy

Harnessing the potential of nanoengineered siRNAs carriers for target responsive glioma therapy: Recent progress and future opportunities

Past scientific testimonials in the field of glioma research, the deadliest tumor among all brain cancer types with the life span of 10-15 months after diagnosis is considered as glioblastoma multiforme (GBM). Even though the availability of treatment options such as chemotherapy, radiotherapy, and surgery, are unable to completely cure GBM due to tumor microenvironment complexity, intrinsic cellular signalling, and genetic mutations which are involved in chemoresistance. The blood-brain barrier is accountable for restricting drugs entry at the tumor location and related biological challenges like endocytic degradation, short systemic circulation, and insufficient cellular penetration lead to tumor aggression and progression. The above stated challenges can be better mitigated by small interfering RNAs (siRNA) by knockdown genes responsible for tumor progression and resistance. However, siRNA encounters with challenges like inefficient cellular transfection, short circulation time, endogenous degradation, and off-target effects. The novel functionalized nanocarrier approach in conjunction with biological and chemical modification offers an intriguing potential to address challenges associated with the naked siRNA and efficiently silence STAT3, coffilin-1, EGFR, VEGF, SMO, MGMT, HAO-1, GPX-4, TfR, LDLR and galectin-1 genes in GBM tumor. This review highlights the nanoengineered siRNA carriers, their recent advancements, future perspectives, and strategies to overcome the systemic siRNA delivery challenges for glioma treatment.

Anti-EGFR ScFv functionalized exosomes delivering LPCAT1 specific siRNAs for inhibition of lung cancer brain metastases

Brain metastasis (BM) is one of the leading causes of cancer-related deaths in patients with advanced non-small cell lung cancer (NSCLC). However, limited treatments are available due to the presence of the blood-brain barrier (BBB). Upregulation of lysophosphatidylcholine acyltransferase 1 (LPCAT1) in NSCLC has been found to promote BM. Conversely, downregulating LPCAT1 significantly suppresses the proliferation and metastasis of lung cancer cells. In this study, we firstly confirmed significant upregulation of LPCAT1 in BM sites compared to primary lung cancer by analyzing scRNA dataset. We then designed a delivery system based on a single-chain variable fragment (scFv) targeting the epidermal growth factor receptor (EGFR) and exosomes derived from HEK293T cells to enhance cell-targeting capabilities and increase permeability. Next, we loaded LPCAT1 siRNA (siLPCAT1) into these engineered exosomes (exoscFv). This novel scFv-mounted exosome successfully crossed the BBB in an animal model and delivered siLPCAT1 to the BM site. Silencing LPCAT1 efficiently arrested tumor growth and inhibited malignant progression of BM in vivo without detectable toxicity. Overall, we provided a potential platform based on exosomes for RNA interference (RNAi) therapy in lung cancer BM.

A recognition of exosomes as regulators of epigenetic mechanisms in central nervous system diseases

Exosomes, vesicular structures originating from cells, participate in the conveyance of proteins and nucleic acids. Presently, the centrality of epigenetic modifications in neurological disorders is widely acknowledged. Exosomes exert influence over various epigenetic phenomena, thereby modulating post-transcriptional regulatory processes contingent upon their constituent makeup. Consequently, the heightened attention directed toward exosomes as instigators of epigenetic alterations has burgeoned in recent years. Notably, exosomes serve as vehicles for delivering methyltransferases to recipient cells. More significantly, non-coding RNAs, particularly microRNAs (miRNAs), represent pivotal contents within exosomes, wielding the capacity to influence the expression of diverse factors within the cerebral milieu. The transfer of these exosomal contents amidst brain cells, encompassing neuronal cells and microglia, assumes a critical role in the genesis and progression of neurological disorders, also, this role is not limited to neurological disorders, it may deal with any human disease, such as cancer, and cardiovascular diseases. This review will concentrate on elucidating the regulation of exosome-induced epigenetic events and its subsequent ramifications for neurological diseases. A more profound comprehension of the involvement of exosome-mediated epigenetic regulation in neurological disorders contributes to a heightened awareness of the etiology and advancement of cerebral afflictions.

Bioequivalence and Safety Assessment of 2 Formulations of Low-Dose Metformin Hydrochloride under Fasting Conditions in Healthy Chinese Participants: A Randomized Phase 1 Clinical Trial

The incidence of type 2 diabetes is high, and the existing metformin hydrochloride (MH) tablets of 250 mg cannot meet the demands of the Chinese drug market. This study aimed to evaluate the bioequivalence and safety of generic formulations of MH tablets (test formulation [T], 250 mg/tablet) and innovative products (reference formulation [R], 250 mg/tablet) under fasting conditions. This was an open-label, single-dose, 2-period, 2-sequence crossover, single-center, randomized phase I clinical trial. T and R were considered bioequivalent if the adjusted geometric mean ratios (GMRs) and 90% confidence intervals of the area under the curve (AUC) and maximum concentration (Cmax ) were within the range of 0.8-1.25. Thirty-five participants completed the trial. The T/R adjusted GMRs (95.7% for Cmax , 98.7% for AUC0→t , 98.8% for AUC0→∞ ) were within the acceptable bioequivalence range of 80%-125%. No serious adverse events or suspected or unexpected serious adverse reactions occurred during this trial. The study findings confirmed that generic MH is a well-tolerated and bioequivalent alternative to innovative products under fasting conditions in healthy Chinese participants. (www.chinadrugtrials.org.cn; registration no. CTR20190356).

Exosomes in Glioma: Unraveling Their Roles in Progression, Diagnosis, and Therapy

Gliomas, the most prevalent primary malignant brain tumors, present a challenging prognosis even after undergoing surgery, radiation, and chemotherapy. Exosomes, nano-sized extracellular vesicles secreted by various cells, play a pivotal role in glioma progression and contribute to resistance against chemotherapy and radiotherapy by facilitating the transportation of biological molecules and promoting intercellular communication within the tumor microenvironment. Moreover, exosomes exhibit the remarkable ability to traverse the blood-brain barrier, positioning them as potent carriers for therapeutic delivery. These attributes hold promise for enhancing glioma diagnosis, prognosis, and treatment. Recent years have witnessed significant advancements in exosome research within the realm of tumors. In this article, we primarily focus on elucidating the role of exosomes in glioma development, highlighting the latest breakthroughs in therapeutic and diagnostic approaches, and outlining prospective directions for future research.

Galectin inhibitors and nanoparticles as a novel therapeutic strategy for glioblastoma multiforme

Over the past two decades, the gold standard of glioblastoma multiforme (GBM) treatment is unchanged and adjunctive therapy has offered little to prolong both quality and quantity of life. To improve pharmacotherapy for GBM, galectins are being studied provided their positive correlation with the malignancy and disease severity. Despite the use of galectin inhibitors and literature displaying the ability of the lectin proteins to decrease tumor burden and decrease mortality within various malignancies, galectin inhibitors have not been studied for GBM therapy. Interestingly, anti-galectin siRNA delivered in nanoparticle capsules, assisting in blood brain barrier penetrance, is well studied for GBM, and has demonstrated a remarkable ability to attenuate both galectin and tumor count. Provided that the two therapies have an analogous anti-galectin effect, it is hypothesized that galectin inhibitors encapsuled within nanoparticles will likely have a similar anti-galectin effect in GBM cells and further correlate to a repressed tumor burden.

Current progression in application of extracellular vesicles in central nervous system diseases

Early diagnosis and pharmacological treatment of central nervous system (CNS) diseases has been a long-standing challenge for clinical research due to the presence of the blood-brain barrier. Specific proteins and RNAs in brain-derived extracellular vesicles (EVs) usually reflect the corresponding state of brain disease, and therefore, EVs can be used as diagnostic biomarkers for CNS diseases. In addition, EVs can be engineered and fused to target cells for delivery of cargo, demonstrating the great potential of EVs as a nanocarrier platform. We review the progress of EVs as markers and drug carriers in the diagnosis and treatment of neurological diseases. The main areas include visual imaging, biomarker diagnosis and drug loading therapy for different types of CNS diseases. It is hoped that increased knowledge of EVs will facilitate their clinical translation in CNS diseases.

Establishment and characterization of a recurrent malignant peripheral nerve sheath tumor cell line: RsNF

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive and recurrent soft tissue sarcoma. It most commonly occurs secondary to neurofibromatosis type I, and it has a 5-year survival rate of only 8-13%. To better study the tumor heterogeneity of MPNST and to develop diverse treatment options, more tumor-derived cell lines are needed to obtain richer biological information. Here, we established a primary cell line of relapsed MPNST RsNF cells derived from a patient diagnosed with NF1 and detected the presence of NF1 mutations and SUZ12 somatic mutations through whole-exome sequencing(WES). Through tumor molecular marker targeted sequencing and single-cell transcriptome sequencing, it was found that chromosome 7 copy number variation (CNV) was gained in this cell line, and ZNF804B, EGFR, etc., were overexpressed on chromosome 7. Therefore, RsNF cells can be used as a useful tool in NF1-associated MPNST genomic amplification studies and to develop new therapeutic strategies.

Temozolomide and flavonoids against glioma: from absorption and metabolism to exosomal delivery

Patients with glioblastoma multiforme and anaplastic astrocytoma are treated with temozolomide. Although it has been demonstrated that temozolomide increases GBM patient survival, it has also been connected to negative immune-related adverse effects. Numerous research investigations have shown that flavonoids have strong antioxidant and chemo-preventive effects. Consequently, it might lessen chemotherapeutic medicines' side effects while also increasing therapeutic effectiveness. The need for creating innovative, secure, and efficient drug carriers for cancer therapy has increased over time. Recent research indicates that exosomes have enormous potential to serve as carriers and cutting-edge drug delivery systems to the target cell. In recent years, researchers have been paying considerable attention to exosomes because of their favorable biodistribution, biocompatibility, and low immunogenicity. In the present review, the mechanistic information of the anti-glioblastoma effects of temozolomide and flavonoids coupled with their exosomal delivery to the targeted cell has been discussed. In addition, we discuss the safety aspects of temozolomide and flavonoids against glioma. The in-depth information of temozolomide and flavonoids action via exosomal delivery can unravel novel strategies to target Glioma.

Roles of extracellular vesicles in glioblastoma: foes, friends and informers

Glioblastoma (GB) tumors are one of the most insidious cancers which take over the brain and defy therapy. Over time and in response to treatment the tumor and the brain cells in the tumor microenvironment (TME) undergo many genetic/epigenetic driven changes in their phenotypes and this is reflected in the cellular contents within the extracellular vesicles (EVs) they produce. With the result that some EVs try to subdue the tumor (friends of the brain), while others participate in the glioblastoma takeover (foes of the brain) in a dynamic and ever changing process. Monitoring the contents of these EVs in biofluids can inform decisions based on GB status to guide therapeutic intervention. This review covers primarily recent research describing the different cell types in the brain, as well as the tumor cells, which participate in this EV deluge. This includes EVs produced by the tumor which manipulate the transcriptome of normal cells in their environment in support of tumor growth (foes), as well as responses of normal cells which try to restrict tumor growth and invasion, including traveling to cervical lymph nodes to present tumor neo-antigens to dendritic cells (DCs). In addition EVs released by tumors into biofluids can report on the status of living tumor cells via their cargo and thus serving as biomarkers. However, EVs released by tumor cells and their influence on normal cells in the tumor microenvironment is a major factor in immune suppression and coercion of normal brain cells to join the GB "band wagon". Efforts are being made to deploy EVs as therapeutic vehicles for drugs and small inhibitory RNAs. Increasing knowledge about EVs in the TME is being utilized to track tumor progression and response to therapy and even to weaponize EVs to fight the tumor.

Epigenomic perturbation of novel EGFR enhancers reduces the proliferative and invasive capacity of glioblastoma and increases sensitivity to temozolomide

BACKGROUND

Glioblastoma (GB) is the most aggressive of all primary brain tumours and due to its highly invasive nature, surgical resection is nearly impossible. Patients typically rely on radiotherapy with concurrent temozolomide (TMZ) treatment and face a median survival of ~ 14 months. Alterations in the Epidermal Growth Factor Receptor gene (EGFR) are common in GB tumours, but therapies targeting EGFR have not shown significant clinical efficacy.

METHODS

Here, we investigated the influence of the EGFR regulatory genome on GB cells and identified novel EGFR enhancers located near the GB-associated SNP rs723527. We used CRISPR/Cas9-based approaches to target the EGFR enhancer regions, generating multiple modified GB cell lines, which enabled us to study the functional response to enhancer perturbation.

RESULTS

Epigenomic perturbation of the EGFR regulatory region decreases EGFR expression and reduces the proliferative and invasive capacity of glioblastoma cells, which also undergo a metabolic reprogramming in favour of mitochondrial respiration and present increased apoptosis. Moreover, EGFR enhancer-perturbation increases the sensitivity of GB cells to TMZ, the first-choice chemotherapeutic agent to treat glioblastoma.

CONCLUSIONS

Our findings demonstrate how epigenomic perturbation of EGFR enhancers can ameliorate the aggressiveness of glioblastoma cells and enhance the efficacy of TMZ treatment. This study demonstrates how CRISPR/Cas9-based perturbation of enhancers can be used to modulate the expression of key cancer genes, which can help improve the effectiveness of existing cancer treatments and potentially the prognosis of difficult-to-treat cancers such as glioblastoma.

Sertoli cell-derived extracellular vesicles traverse the blood-testis barrier and deliver miR-24-3p inhibitor into germ cells improving sperm mobility

Asthenozoospermia, characterized by poor sperm motility, is a common cause of male infertility. Improving energy metabolism and alleviating oxidative stress through drug regimens are potential therapeutic strategies. In this study, we observed upregulated miR-24-3p levels in asthenozoospermia spermatozoa, contributing to energy metabolism disorder and oxidative stress by reducing GSK3β expression. Thus, reducing miR-24-3p levels using drugs is expected to improve sperm motility. The blood-testis barrier (BTB) protects the testis from xenobiotics and drugs. In this study, we found that Sertoli cell-derived small extracellular vesicles (SC-sEV) can traverse the BTB and enter germ cells. We successfully loaded miR-24-3p inhibitor into SC-sEV, creating the nano-drug SC-sEV@miR-24-3p inhibitor, which effectively delivers miR-24-3p inhibitor into germ cells. In a gossypol-induced mouse asthenozoospermia model, administration of SC-sEV@miR-24-3p inhibitor significantly improved sperm motility, in vitro fertilization success, and blastocyst formation rates. As anticipated, it also improved the litter size of asthenozoospermia mice. These results suggest that SC-sEV@miR-24-3p inhibitor holds promise as a potential clinical treatment for asthenospermia.

Inhibition of O-GlcNAcylation Reduces Cell Viability and Autophagy and Increases Sensitivity to Chemotherapeutic Temozolomide in Glioblastoma

Glioblastoma (GB) is the most aggressive primary malignant brain tumor and is associated with short survival. O-GlcNAcylation is an intracellular glycosylation that regulates protein function, enzymatic activity, protein stability, and subcellular localization. Aberrant O-GlcNAcylation is related to the tumorigenesis of different tumors, and mounting evidence supports O-GlcNAc transferase (OGT) as a potential therapeutic target. Here, we used two human GB cell lines alongside primary human astrocytes as a non-tumoral control to investigate the role of O-GlcNAcylation in cell proliferation, cell cycle, autophagy, and cell death. We observed that hyper O-GlcNAcylation promoted increased cellular proliferation, independent of alterations in the cell cycle, through the activation of autophagy. On the other hand, hypo O-GlcNAcylation inhibited autophagy, promoted cell death by apoptosis, and reduced cell proliferation. In addition, the decrease in O-GlcNAcylation sensitized GB cells to the chemotherapeutic temozolomide (TMZ) without affecting human astrocytes. Combined, these results indicated a role for O-GlcNAcylation in governing cell proliferation, autophagy, cell death, and TMZ response, thereby indicating possible therapeutic implications for treating GB. These findings pave the way for further research and the development of novel treatment approaches which may contribute to improved outcomes and increased survival rates for patients facing this challenging disease.

Engineered exosomes as drug and RNA co-delivery system: new hope for enhanced therapeutics?

Chemotherapy often faces some obstacles such as low targeting effects and drug resistance, which introduce the low therapeutic efficiency and strong side effects. Recent advances in nanotechnology allows the use of novel nanosystems for targeted drug delivery, although the chemically synthesized nanomaterials always show unexpected low biocompability. The emergence of exosome research has offered a better understanding of disease treatment and created novel opportunities for developing effective drug delivery systems with high biocompability. Moreover, RNA interference has emerged as a promising strategy for disease treatments by selectively knocking down or over-expressing specific genes, which allows new possibilities to directly control cell signaling events or drug resistance. Recently, more and more interests have been paid to develop optimal delivery nanosystems with high efficiency and high biocompability for drug and functional RNA co-delivery to achieve enhanced chemotherapy. In light of the challenges for developing drug and RNA co-delivery system, exosomes have been found to show very attractive prospects. This review aims to explore current technologies and challenges in the use of exosomes as drug and RNA co-delivery system with a focus on the emerging trends and issues associated with their further applications, which may contribute to the accelerated developments of exosome-based theraputics.

The Dual Effects of Exosomes on Glioma: A Comprehensive Review

Glioma is a frequently occurring type of cancer that affects the central nervous system. Despite the availability of standardized treatment options including surgical resection, concurrent radiotherapy, and adjuvant temozolomide (TMZ) therapy, the prognosis for glioma patients is often unfavorable. Exosomes act as vehicles for intercellular communication, contributing to tissue repair, immune modulation, and the transfer of metabolic cargo to recipient cells. However, the transmission of abnormal substances can also contribute to pathologic states such as cancer, metabolic diseases, and neurodegenerative disorders. The field of exosome research in oncology has seen significant advancements, with exosomes identified as dynamic modulators of tumor cell proliferation, migration, and invasion, as well as angiogenesis and drug resistance. Exosomes have negligible cytotoxicity, low immunogenicity, and small size, rendering them an ideal therapeutic candidate for glioma. This comprehensive review discusses the dual effects of exosomes in glioma, with an emphasis on their role in facilitating drug resistance. Furthermore, the clinical applications and current limitations of exosomes in glioma therapy are also discussed in detail.

Advanced hitchhiking nanomaterials for biomedical applications

Hitchhiking, a recently developed bio-inspired cargo delivery system, has been harnessed for diverse applications. By leveraging the interactions between nanoparticles and circulatory cells or proteins, hitchhiking enables efficient navigation through the vasculature while evading immune system clearance. Moreover, it allows for targeted delivery of nutrients to tissues, surveillance of the immune system, and pathogen elimination. Various synthetic nanomaterials have been developed to facilitate hitchhiking with circulatory cells or proteins. By combining the advantages of synthetic nanomaterials and circulatory cells or proteins, hitchhiking nanomaterials demonstrate several advantages over conventional vectors, including enhanced circulatory stability and optimized therapeutic efficacy. This review provides an overview of general strategies for hitchhiking, choices of cells and proteins, and recent advances of hitchhiking nanomaterials for biomedical applications.

Engineered extracellular vesicles-like biomimetic nanoparticles as an emerging platform for targeted cancer therapy

Nanotechnology offers the possibility of revolutionizing cancer theranostics in the new era of precision oncology. Extracellular vesicles (EVs)-like biomimetic nanoparticles (EBPs) have recently emerged as a promising platform for targeted cancer drug delivery. Compared with conventional synthetic vehicles, EBPs have several advantages, such as lower immunogenicity, longer circulation time, and better targeting capability. Studies on EBPs as cancer therapeutics are rapidly progressing from in vitro experiments to in vivo animal models and early-stage clinical trials. Here, we describe engineering strategies to further improve EBPs as effective anticancer drug carriers, including genetic manipulation of original cells, fusion with synthetic nanomaterials, and direct modification of EVs. These engineering approaches can improve the anticancer performance of EBPs, especially in terms of tumor targeting effectiveness, stealth property, drug loading capacity, and integration with other therapeutic modalities. Finally, the current obstacles and future perspectives of engineered EBPs as the next-generation delivery platform for anticancer drugs are discussed.

Empagliflozin: a potential anticancer drug

Empagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is a highly effective and well-tolerated antidiabetic drug. In addition to hypoglycemic effects, empagliflozin has many other effects, such as being hypotensive and cardioprotective. It also has anti-inflammatory and antioxidative stress effects in diabetic nephropathy. Several studies have shown that empagliflozin has anticancer effects. SGLT2 is expressed in a variety of cancer cell lines. The SGLT2 inhibitor empagliflozin has significant inhibitory effects on certain types of tumor cells, such as inhibition of proliferation, migration and induction of apoptosis. In conclusion, empagliflozin has promising applications in cancer therapy as a drug for the treatment of diabetes and heart failure. This article provides a brief review of the anticancer effects of empagliflozin.

Spheresomes are the main extracellular vesicles in low-grade gliomas

Cancer progression and its impact on treatment response and prognosis is deeply regulated by tumour microenvironment (TME). Cancer cells are in constant communication and modulate TME through several mechanisms, including transfer of tumour-promoting cargos through extracellular vesicles (EVs) or oncogenic signal detection by primary cilia. Spheresomes are a specific EV that arise from rough endoplasmic reticulum-Golgi vesicles. They accumulate beneath cell membrane and are released to the extracellular medium through multivesicular spheres. This study describes spheresomes in low-grade gliomas using electron microscopy. We found that spheresomes are more frequent than exosomes in these tumours and can cross the blood-brain barrier. Moreover, the distinct biogenesis processes of these EVs result in unique cargo profiles, suggesting different functional roles. We also identified primary cilia in these tumours. These findings collectively contribute to our understanding of glioma progression and metastasis.

Could Metformin and Resveratrol Support Glioblastoma Treatment? A Mechanistic View at the Cellular Level

Glioblastoma, a malignant brain tumor, is a common primary brain tumor in adults, with diabetes mellitus being a crucial risk factor. This review examines how the antidiabetic drug metformin and dietary supplement resveratrol can benefit the treatment of glioblastoma. Metformin and resveratrol have demonstrated action against relevant pathways in cancer cells. Metformin and resveratrol inhibit cell proliferation by downregulating the PI3K/Akt pathway, activating mTOR, and increasing AMPK phosphorylation, resulting in lower proliferation and higher apoptosis levels. Metformin and resveratrol both upregulate and inhibit different cascades in the MAPK pathway. In vivo, the drugs reduced tumor growth and volume. These actions show how metformin and resveratrol can combat cancer with both glucose-dependent and glucose-independent effects. The pre-clinical results, alongside the lack of clinical studies and the rise in novel delivery mechanisms, warrant further clinical investigations into the applications of metformin and resveratrol as both separate and as a combination complement to current glioblastoma therapies.

The Role of Long Noncoding Ribonucleic Acids in Glioblastoma: What the Neurosurgeon Should Know

A significant proportion of the human transcriptome, long noncoding RNAs (lncRNAs) play pivotal roles in several aspects of glioblastoma (GBM) pathophysiology including proliferation, invasion, radiation and temozolomide resistance, and immune modulation. The majority of lncRNAs exhibit tissue- and tumor-specific expression, lending them to be attractive targets for therapeutic translation. In recent years, unprecedented progress has been made toward our understanding of lncRNA in GBM. In this review, we discuss the function of lncRNAs, including specific lncRNAs that have critical roles in key aspects of GBM pathophysiology, and potential clinical relevance of lncRNAs for patients with GBM.

Engineering Extracellular Vesicles as Delivery Systems in Therapeutic Applications

Extracellular vesicles (EVs) are transport vesicles secreted by living cells and released into the extracellular environment. Recent studies have shown that EVs serve as "messengers" in intercellular and inter-organismal communication, in both normal and pathological processes. EVs, as natural nanocarriers, can deliver bioactivators in therapy with their endogenous transport properties. This review article describes the engineering EVs of sources, isolation method, cargo loading, boosting approach, and adjustable targeting of EVs. Furthermore, the review summarizes the recent progress made in EV-based delivery systems applications, including cancer, cardiovascular diseases, liver, kidney, nervous system diseases, and COVID-19 and emphasizes the obstacles and challenges of EV-based therapies and possible strategies.

Glioblastoma Metabolism: Insights and Therapeutic Strategies

Tumor metabolism is emerging as a potential target for cancer therapies. This new approach holds particular promise for the treatment of glioblastoma, a highly lethal brain tumor that is resistant to conventional treatments, for which improving therapeutic strategies is a major challenge. The presence of glioma stem cells is a critical factor in therapy resistance, thus making it essential to eliminate these cells for the long-term survival of cancer patients. Recent advancements in our understanding of cancer metabolism have shown that glioblastoma metabolism is highly heterogeneous, and that cancer stem cells exhibit specific metabolic traits that support their unique functionality. The objective of this review is to examine the metabolic changes in glioblastoma and investigate the role of specific metabolic processes in tumorigenesis, as well as associated therapeutic approaches, with a particular focus on glioma stem cell populations.

Therapeutic and Diagnostic Potential of Exosomes as Drug Delivery Systems in Brain Cancer

Cancer is designated as one of the principal causes of mortality universally. Among different types of cancer, brain cancer remains the most challenging one due to its aggressiveness, the ineffective permeation ability of drugs through the blood-brain barrier (BBB), and drug resistance. To overcome the aforementioned issues in fighting brain cancer, there is an imperative need for designing novel therapeutic approaches. Exosomes have been proposed as prospective "Trojan horse" nanocarriers of anticancer theranostics owing to their biocompatibility, increased stability, permeability, negligible immunogenicity, prolonged circulation time, and high loading capacity. This review provides a comprehensive discussion on the biological properties, physicochemical characteristics, isolation methods, biogenesis and internalization of exosomes, while it emphasizes their therapeutic and diagnostic potential as drug vehicle systems in brain cancer, highlighting recent advances in the research field. A comparison of the biological activity and therapeutic effectiveness of several exosome-encapsulated cargo including drugs and biomacromolecules underlines their great supremacy over the non-exosomal encapsulated cargo in the delivery, accumulation, and biological potency. Various studies on cell lines and animals give prominence to exosome-based nanoparticles (NPs) as a promising and alternative approach in the management of brain cancer.

Phospholipases in Gliomas: Current Knowledge and Future Perspectives from Bench to Bedside

Phospholipases are essential intermediaries that work as hydrolyzing enzymes of phospholipids (PLs), which represent the most abundant species contributing to the biological membranes of nervous cells of the healthy human brain. They generate different lipid mediators, such as diacylglycerol, phosphatidic acid, lysophosphatidic acid, and arachidonic acid, representing key elements of intra- and inter-cellular signaling and being involved in the regulation of several cellular mechanisms that can promote tumor progression and aggressiveness. In this review, it is summarized the current knowledge about the role of phospholipases in brain tumor progression, focusing on low- and high-grade gliomas, representing promising prognostic or therapeutic targets in cancer therapies due to their influential roles in cell proliferation, migration, growth, and survival. A deeper understanding of the phospholipases-related signaling pathways could be necessary to pave the way for new targeted therapeutic strategies.

Engineered extracellular vesicles (EVs): Promising diagnostic/therapeutic tools for pediatric high-grade glioma

Diffuse intrinsic pontine glioma (DIPG) is a highly malignant brain tumor that mainly occurs in children with extremely low overall survival. Traditional therapeutic strategies, such as surgical resection and chemotherapy, are not feasible mostly due to the special location and highly diffused features. Radiotherapy turns out to be the standard treatment method but with limited benefits of overall survival. A broad search for novel and targeted therapies is in the progress of both preclinical investigations and clinical trials. Extracellular vesicles (EVs) emerged as a promising diagnostic and therapeutic candidate due to their distinct biocompatibility, excellent cargo-loading-delivery capacity, high biological barrier penetration efficiency, and ease of modification. The utilization of EVs in various diseases as biomarker diagnoses or therapeutic agents is revolutionizing modern medical research and practice. In this review, we will briefly talk about the research development of DIPG, and present a detailed description of EVs in medical applications, with a discussion on the application of engineered peptides on EVs. The possibility of applying EVs as a diagnostic tool and drug delivery system in DIPG is also discussed.

Living Cells and Cell-Derived Vesicles: A Trojan Horse Technique for Brain Delivery

Brain diseases remain a significant global healthcare burden. Conventional pharmacological therapy for brain diseases encounters huge challenges because of the blood-brain barrier (BBB) limiting the delivery of therapeutics into the brain parenchyma. To address this issue, researchers have explored various types of drug delivery systems. Cells and cell derivatives have attracted increasing interest as "Trojan horse" delivery systems for brain diseases, owing to their superior biocompatibility, low immunogenicity, and BBB penetration properties. This review provided an overview of recent advancements in cell- and cell-derivative-based delivery systems for the diagnosis and treatment of brain diseases. Additionally, it discussed the challenges and potential solutions for clinical translation.

Research progress of exosomes as drug carriers in cancer and inflammation

Extracellular vesicles (EVs) could be produced by most cells and play an important role in disease development. As a subtype of EVs, exosomes exhibit suitable size, rich surface markers and diverse contents, making them more appealing as potential drug carriers. Compared with traditional synthetic nanoparticles, exosomes possess superior biocompatibility and much lower immunogenicity. This work reviewed the most up-to-date research progress of exosomes as carriers for nucleic acids, proteins and small molecule drugs for cancer and inflammation management. The drug loading strategies and potential cellular uptake behaviour of exosomes are highlighted, trying to provide reference for future exosome design and application.

Extracellular vesicles in cancer therapy

Extracellular vesicles (EVs), including a variety of membrane-enclosed nanosized particles carrying cell-derived cargo, mediate a major type of intercellular communication in physiological and pathological processes. Both cancer and non-cancer cells secrete EVs, which can travel to and influence various types of cells at the primary tumor site as well as in distant organs. Tumor-derived EVs contribute to cancer cell plasticity and resistance to therapy, adaptation of tumor microenvironment, local and systemic vascular remodeling, immunomodulation, and establishment of pre-metastatic niches. Therefore, targeting the production, uptake, and function of tumor-derived EVs has emerged as a new strategy for stand-alone or combinational therapy of cancer. On the other hand, as EV cargo partially reflects the genetic makeup and phenotypic properties of the secreting cell, EV-based biomarkers that can be detected in biofluids are being developed for cancer diagnosis and for predicting and monitoring tumor response to therapy. Meanwhile, EVs from presumably safe sources are being developed as delivery vehicles for anticancer therapeutic agents and as anticancer vaccines. Numerous reviews have discussed the biogenesis and characteristics of EVs and their functions in cancer. Here, I highlight recent advancements in translation of EV research outcome towards improved care of cancer, including developments of non-invasive EV-based biomarkers and therapeutic agents targeting tumor-derived EVs as well as engineering of therapeutic EVs.

Nanoengineering facilitating the target mission: targeted extracellular vesicles delivery systems design

Precision medicine has put forward the proposition of "precision targeting" for modern drug delivery systems. Inspired by techniques from biology, pharmaceutical sciences, and nanoengineering, numerous targeted drug delivery systems have been developed in recent decades. But the large-scale applications of these systems are limited due to unsatisfactory targeting efficiency, cytotoxicity, easy removability, and instability. As such, the natural endogenous cargo delivery vehicle-extracellular vesicles (EVs)-have sparked significant interest for its unique inherent targeting properties, biocompatibility, transmembrane ability, and circulatory stability. The membranes of EVs are enriched for receptors or ligands that interact with target cells, which endows them with inherent targeting mission. However, most of the natural therapeutic EVs face the fate of being cleared by macrophages, resulting in off-target. Therefore, the specificity of natural EVs delivery systems urgently needs to be further improved. In this review, we comprehensively summarize the inherent homing mechanisms of EVs and the effects of the donor cell source and administration route on targeting specificity. We then go over nanoengineering techniques that modify EVs for improving specific targeting, such as source cell alteration and modification of EVs surface. We also highlight the auxiliary strategies to enhance specificity by changing the external environment, such as magnetic and photothermal. Furthermore, contemporary issues such as the lack of a gold standard for assessing targeting efficiency are discussed. This review will provide new insights into the development of precision medicine delivery systems.