Potential of Mesenchymal Stromal Cell-Derived Extracellular Vesicles as Natural Nanocarriers: Concise Review

Targeted drug delivery of cancer cell-derived extracellular vesicles decorated with a VEGFR-binding peptide

Chemotherapy is commonly used to manage cancer lesions, but its use is limited or has a high risk of failure due to the side effects of the drugs. The use of a drug delivery system can minimize the side effects of drugs and maximize their anticancer effects. This study investigated the potential of tumor cell-derived small extracellular vesicles (sEV) as drug delivery vehicles for doxorubicin (Dox). In addition, the decoration of vascular endothelial growth factor receptor (VEGFR)-targeting peptide on the sEV provided an enhance specific cancer cell-targeting effect in vitro or homing capacity in vivo. The extrusion method was effective in loading Dox and displaying targeting peptide. The effective Dox release was resulted under acidic condition, an endosome pH. The growth of tumor masses on MCF-7 xenografted mice were significantly inhibited by this drug delivery system. We believe that our results will provide useful information for the development of chemotherapeutic drug delivery systems.

Human umbilical cord mesenchymal stem cell exosomes deliver potent oncolytic reovirus to acute myeloid leukemia cells

In addition to chemotherapy, oncolytic viruses are an efficient treatment for acute myeloid leukemia (AML). Like other oncolytic viruses, the anti-tumor efficacy of reovirus when administered intravenously is reduced due to the presence of neutralizing antibodies. In this study, we evaluated the role of exosomes in human umbilical cord-derived mesenchymal stem cells (UC-MSCs) to deliver reovirus to AML cells. We show that UC-MSCs loaded with reovirus can deliver reovirus to tumor cells without cellular contact. We further demonstrate that the exosome inhibitor, GW4869, inhibits the release of exosomes as well as inhibited the transfer of reovirus from UC-MSCs to tumor cells. Mechanistically, we show that exosomes derived from reovirus-infected UC-MSCs (MSCREO-EXOs) have a tumor lysis effect and transmit reovirus to tumor cells mainly through clathrin-mediated endocytosis (CME) and macropinocytosis. In addition, we demonstrate the feasibility of using MSC-derived exosomes (MSC-EXOs) as a reovirus carrier to exert an anti-tumor effect on AML cells. Collectively, our data indicate that UC-MSCs transfer reovirus to AML cells via exosome release and prompt further study of MSC-EXOs as a potential reovirus carrier to treat AML.

Quantitative Analysis of Complement Membrane Attack Complex Proteins Associated with Extracellular Vesicles

Extracellular vesicles (EVs) represent a universal mechanism of intercellular communication in normal and pathological conditions. There are reports showing the presence of complement proteins in EV preparations, specifically those that can form a membrane attack complex (MAC). In the present work, we have used a quantitative mass spectrometry method that allows for the measurement of multiple targeted proteins in one experimental run. The quantification of MAC-forming proteins, namely C5b, C6, C7, C8, and C9, in highly purified EVs from normal human plasma revealed the presence of MAC proteins at approximately equal stoichiometry that does not fit the expected stoichiometry of preformed MAC. We concluded that while MAC proteins can be associated with EVs from normal plasma and presumably can be delivered to the recipient cells, there is no evidence that the EVs carry preformed MAC.

Therapeutic strategy of biological macromolecules based natural bioactive compounds of diabetes mellitus and future perspectives: A systematic review

High blood glucose levels are a hallmark of the metabolic syndrome known as diabetes mellitus. More than 600 million people will have diabetes by 2045 as the global prevalence of the disease continues to rise. Contemporary antidiabetic drugs reduce hyperglycemia and its consequences. However, these drugs come with undesirable side effects, so it's encouraging that research into plant extracts and bioactive substances with antidiabetic characteristics is on the rise. Natural remedies are preferable to conventional anti-diabetic drugs since they are safer for the body, more affordable and have fewer potential adverse effects. Biological macromolecules such as liposomes, niosomes, polymeric nanoparticles, solid lipid nanoparticles, nanoemulsions and metallic nanoparticles are explored in this review. Current drug restrictions have been addressed, and the effectiveness of plant-based antidiabetic therapies has enhanced the merits of these methods. Plant extracts' loading capacity and the carriers' stability are the primary obstacles in developing plant-based nanocarriers. Hydrophilic, hydrophobic, and amphiphilic drugs are covered, and a brief overview of the amphipathic features of liposomes, phospholipids, and lipid nanocarriers is provided. Metallic nanoparticles' benefits and attendant risks are highlighted to emphasize their efficiency in treating hyperglycemia. Researchers interested in the potential of nanoparticles loaded with plant extracts as antidiabetic therapeutics may find the current helpful review.

Current research trends of nanomedicines

Owing to the inherent shortcomings of traditional therapeutic drugs in terms of inadequate therapeutic efficacy and toxicity in clinical treatment, nanomedicine designs have received widespread attention with significantly improved efficacy and reduced non-target side effects. Nanomedicines hold tremendous theranostic potential for treating, monitoring, diagnosing, and controlling various diseases and are attracting an unfathomable amount of input of research resources. Against the backdrop of an exponentially growing number of publications, it is imperative to help the audience get a panorama image of the research activities in the field of nanomedicines. Herein, this review elaborates on the development trends of nanomedicines, emerging nanocarriers, in vivo fate and safety of nanomedicines, and their extensive applications. Moreover, the potential challenges and the obstacles hindering the clinical translation of nanomedicines are also discussed. The elaboration on various aspects of the research trends of nanomedicines may help enlighten the readers and set the route for future endeavors.

Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stromal Cells as an Efficient Nanocarrier to Deliver siRNA or Drug to Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Treatment of PDAC remains a major challenge. This study aims to evaluate, in vitro, the use of human umbilical cord mesenchymal stromal cell (UC-MSC)-derived EVs to specifically target pancreatic cancer cells. EVs were isolated from the FBS-free supernatants of the cultured UC-MSCs by ultracentrifugation and characterized by several methods. EVs were loaded with scramble or KRAS^G12D-targeting siRNA by electroporation. The effects of control and loaded EVs on different cell types were evaluated by assessing cell proliferation, viability, apoptosis and migration. Later, the ability of EVs to function as a drug delivery system for doxorubicin (DOXO), a chemotherapeutic drug, was also evaluated. Loaded EVs exhibited different kinetic rates of uptake by three cell lines, namely, BxPC-3 cells (pancreatic cancer cell line expressing KRAS^wt), LS180 cells (colorectal cell line expressing KRAS^G12D) and PANC-1 cells (pancreatic cell line expressing KRAS^G12D). A significant decrease in the relative expression of the KRAS^G12D gene after incubation with KRAS siRNA EVs was observed by real-time PCR. KRAS^G12D siRNA EVs significantly reduced the proliferation, viability and migration of the KRAS^G12D cell lines compared to scramble siRNA EVs. An endogenous EV production method was applied to obtain DOXO-loaded EVs. Briefly, UC-MSCs were treated with DOXO. After 24 h, UC-MSCs released DOXO-loaded EVs. DOXO-loaded EVs were rapidly taken up by PANC-1 cells and induced apoptotic cell death more efficiently than free DOXO. In conclusion, the use of UC-MSC-derived EVs as a drug delivery system for siRNAs or drugs could be a promising approach for the targeted treatment of PDAC.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.