Bacteria-derived outer membrane vesicles engineered with over-expressed pre-miRNA as delivery nanocarriers for cancer therapy

Advancements in Cell Membrane-Derived Biomimetic Nanotherapeutics for Breast Cancer

Breast cancer remains the leading cause of female mortality worldwide, necessitating innovative and multifaceted approaches to address its various subtypes. Nanotechnology has attracted considerable attention due to its nanoscale dimensions, diverse carrier types, suitability for hydrophobic drug delivery, and capacity for controlled and targeted administration. Nano-sized particles have become prevalent carriers for therapeutic agents targeting breast cancer, thanks to their reproducible synthesis and adjustable properties, including size, shape, and surface characteristics. In addition, certain nanoparticles can enhance therapeutic effects synergistically. However, the immune system often detects and removes these nanoparticles, limiting their efficacy. As a promising alternative, cell membrane-based delivery systems have gained attention due to their biocompatibility and targeting specificity. These membrane-coated drug delivery systems are derived from various cell sources, including blood cells, cancer cells, and stem cells. Leveraging the unique properties of these cell membranes enables precise targeting of breast cancer tumors and associated biomarkers. Inspired by natural structures, cell membranes disguise nanoparticles in the bloodstream, enhancing their retention time in vivo and improving tumor targeting. Consequently, cell membrane-derived nanoparticles (CMDNPs) have been investigated for their potential applications in breast cancer diagnostics, photothermal therapy (PTT), and vaccine development. This review comprehensively explores the potential and limitations of cell membrane-derived drug delivery systems in clinical applications against breast cancer.

The potential use of bacteria and their derivatives as delivery systems for nanoparticles in the treatment of cancer

Cancer is a leading cause of mortality and morbidity worldwide. Nanomaterials, unique optical, magnetic, and electrical properties at the nanoscale (1-100 nm), have been engineered to improve drug capacity, bioavailability, and specificity in cancer treatment. These advancements address toxicity and lack of selectivity in conventional therapies, enabling precise targeting of cancer cells, the tumour microenvironment, and the immune system. Among emerging approaches, bacterial treatment shows promise due to its natural ability to target cancer and its diverse therapeutic mechanisms, which nanotechnology can further enhance. Bacteria-based drug delivery systems leverage bacteria's adaptability and survival strategies within the human body. Bacterial derivatives, such as bacterial ghosts (BGs), bacterial extracellular vesicles (BEVs), and dietary toxins, are recognised as effective biological nanomaterials capable of carrying nanoparticles (NPs). These systems have attracted increasing attention for their potential in targeted NP delivery for cancer treatment. This study explores the use of various bacteria and their byproducts as NP delivery vehicles, highlighting their potential in treating different types of cancer. By combining the strengths of nanotechnology and bacterial therapy, these innovative approaches aim to revolutionise cancer treatment with improved precision and efficacy.

Bacterial outer membrane vesicles in tumor prevention and treatment: advancements in research and application

As one of the major challenges to global health, the innovation of prevention and treatment methods for tumors has consistently been a focal point in medical research. In recent years, bacterial membrane vesicles (MVs), particularly outer membrane vesicles (OMVs) secreted by Gram-negative bacteria, have garnered significant attention due to their unique biological characteristics and potential anti-tumor effects. OMVs are bilayer lipid nanocapsules that are actively released by bacteria during their growth, typically ranging in diameter from 20 to 300 nm. They are rich in various biomolecules, including lipids, proteins, nucleic acids, and other small molecules. These components not only reflect the outer membrane structure of bacteria but also contain numerous pathogen-associated molecular patterns (PAMPs) related to bacterial pathogenicity and immunogenicity. Consequently, OMVs play an important role in bacterial resistance, antimicrobial activity, gene transfer, signal transduction, and immune regulation. Research and application of OMVs in anti-tumor therapy have made significant progress. This paper reviews the classification, characteristics, preparation, safety evaluation, biological functions, and specific research advancements of OMVs as antitumor drugs, immunomodulators, and carriers. Additionally, common methods for the preparation and modification of OMVs, including preliminary extraction, purification, characterization, and drug loading, are discussed. This paper also summarizes the challenges faced by OMVs in anti-tumor research and outlines future development directions, aiming to provide a reference for the further application of OMVs in tumor treatment.

Innovative Strategies in Oncology: Bacterial Membrane Vesicle-Based Drug Delivery Systems for Cancer Diagnosis and Therapy

Outer membrane vesicles (OMVs) are double-layered structures of nanoscale lipids released by gram-negative bacteria. They have the same membrane composition and characteristics as primitive cells, which enables them to penetrate cells and tissues efficiently. These OMVs exhibit excellent membrane stability, immunogenicity, safety, and permeability (which makes it easier for them to penetrate into tumour tissue), making them suitable for developing cancer vaccines and drug delivery systems. Recent studies have focused on engineering OMVs to enhance tumour-targeting capabilities, reduce toxicity, and extend circulation time in vivo. This article reviews the latest progress in OMV engineering for tumour treatment and discusses the challenges associated with the use of OMV-based antitumour therapy in clinical practice.

The emerging role of bacterial extracellular vesicles in human cancers

Bacterial extracellular vesicles (BEVs) have emerged as pivotal mediators between bacteria and host. In addition to being crucial players in host homeostasis, they have recently been implicated in disease pathologies such as cancer. Hence, the study of BEVs represents an intriguing and rapidly evolving field with substantial translational potential. In this review, we briefly introduce the fundamentals of BEV characteristics, cargo and biogenesis. We emphatically summarize the current relationship between BEVs across various cancer types, illustrating their role in tumorigenesis, treatment responses and patient survival. We further discuss the inherent advantages of BEVs, such as stability, abundance and specific cargo profiles, that make them attractive candidates for non-invasive diagnostic and prognostic approaches. The review also explores the potential of BEVs as a strategy for cancer therapy, considering their ability to deliver therapeutic agents, modulate the tumour microenvironment (TME) and elicit immunomodulatory responses. Understanding the clinical significance of BEVs may lead to the development of better-targeted and personalized treatment strategies. This comprehensive review evaluates the current progress surrounding BEVs and poses questions to encourage further research in this emerging field to harness the benefits of BEVs for their full potential in clinical applications against cancer.

Bacterial outer membrane vesicles in the fight against cancer

ABSTRACT

Bacterial outer membrane vesicles (OMVs) are diminutive vesicles naturally released by Gram-negative bacteria. These vesicles possess distinctive characteristics that attract attention for their potential use in drug administration and immunotherapy in cancer treatment. Therapeutic medicines may be delivered via OMVs directly to the tumor sites, thereby minimizing exposure to healthy cells and lowering the risk of systemic toxicity. Furthermore, the activation of the immune system by OMVs has been demonstrated to facilitate the recognition and elimination of cancer cells, which makes them a desirable tool for immunotherapy. They can also be genetically modified to carry specific antigens, immunomodulatory compounds, and small interfering RNAs, enhancing the immune response to cancerous cells and silencing genes associated with disease progression. Combining OMVs with other cancer treatments like chemotherapy and radiation has shown promising synergistic effects. This review highlights the crucial role of bacterial OMVs in cancer, emphasizing their potential as vectors for novel cancer targeted therapies. As researchers delve deeper into the complexities of these vesicles and their interactions with tumors, there is a growing sense of optimism that this avenue of study will bring positive outcomes and renewed hope to cancer patients in the foreseeable future.

Recent advances in various bio-applications of bacteria-derived outer membrane vesicles

Outer membrane vesicles (OMVs) are spherical nanoparticles released from gram-negative bacteria. OMVs were originally classified into native 'nOMVs' (produced naturally from budding of bacteria) and non-native (produced by mechanical means). nOMVs and detergent (dOMVs) are isolated from cell supernatant without any detergent cell disruption techniques and through detergent extraction, respectively. Growth stages and conditions e.g. different stress factors, including temperature, nutrition deficiency, and exposure to hazardous chemical agents can affect the yield of OMVs production and OMVs content. Because of the presence of bacterial antigens, pathogen-associated molecular patterns (PAMPs), various proteins and the vesicle structure, OMVs have been developed in many biomedical applications. OMVs due to their size can be phagocytized by APCs, enter lymph vessels, transport antigens efficiently, and induce both T and B cells immune responses. Non-engineered OMVs have been frequently used as vaccines against different bacterial and viral infections, and various cancers. OMVs can also be used in combination with different antigens as an attractive vaccine adjuvant. Indeed, foreign antigens from target microorganisms can be trapped in the lumen of nonpathogenic vesicles or can be displayed on the surface through bacterial membrane protein to increase the immunogenicity of the antigens. In this review, different factors affecting OMV production including time of cultivation, growth media, stress conditions and genetic manipulations to enhance vesiculation will be described. Furthermore, recent advances in various biological applications of OMVs such as vaccine, drug delivery, cancer therapy, and enzyme carrier are discussed. Generally, the application of OMVs as vaccine carrier in three categories (i.e., non-engineered OMVs, OMVs as an adjuvant, recombinant OMVs (rOMVs)), as delivery system for small interfering RNA and therapeutic agents, and as enzymes carrier will be discussed.

Bifidobacterium-derived membrane vesicles inhibit triple-negative breast cancer growth by inducing tumor cell apoptosis

BACKGROUND

Bacterial outer membrane vesicles have gained increasing attention for its antitumor effect and application in drug delivery. However, the bacterial membrane vesicles (MVs) that are secreted by Gram-positive bacteria are rarely mentioned. Bifidobacterium has a certain anti-tumor effect, but there is a certain risk when injected into human body. Here we investigated the potential of Bifidobacterium-derived membrane vesicles (B-MVs) as therapeutic agents to treat triple-negative breast cancer.

METHODS AND RESULTS

Firstly, we discovered that Bifidobacterium can produce B-MVs and isolated them. In vivo, we found that B-MVs can inhibit tumor growth in mice and the mice were in good state. H&E staining displayed extensive apoptotic cells in tumor tissues. Western blotting and immunohistochemistry showed that B-MVs increased the expression of Bax, while decreased the expression of Bcl-2. These results suggested that B-MVs may induce apoptosis of tumor cells in vivo. Furthermore, to further confirm this phenomenon, we conducted experiments in vitro. Hoechst 33,258 staining assay, flow cytometry and western blotting also demonstrated B-MVs promoted cell apoptosis in vitro.

CONCLUSIONS

We speculate B-MVs may inhibit tumor growth by inducing tumor cell apoptosis in triple-negative breast cancer, which provided a new direction in the treatment of TNBC.

Bacterial Membrane Vesicles as Smart Drug Delivery and Carrier Systems: A New Nanosystems Tool for Current Anticancer and Antimicrobial Therapy

Bacterial membrane vesicles (BMVs) are known to be critical communication tools in several pathophysiological processes between bacteria and host cells. Given this situation, BMVs for transporting and delivering exogenous therapeutic cargoes have been inspiring as promising platforms for developing smart drug delivery systems (SDDSs). In the first section of this review paper, starting with an introduction to pharmaceutical technology and nanotechnology, we delve into the design and classification of SDDSs. We discuss the characteristics of BMVs including their size, shape, charge, effective production and purification techniques, and the different methods used for cargo loading and drug encapsulation. We also shed light on the drug release mechanism, the design of BMVs as smart carriers, and recent remarkable findings on the potential of BMVs for anticancer and antimicrobial therapy. Furthermore, this review covers the safety of BMVs and the challenges that need to be overcome for clinical use. Finally, we discuss the recent advancements and prospects for BMVs as SDDSs and highlight their potential in revolutionizing the fields of nanomedicine and drug delivery. In conclusion, this review paper aims to provide a comprehensive overview of the state-of-the-art field of BMVs as SDDSs, encompassing their design, composition, fabrication, purification, and characterization, as well as the various strategies used for targeted delivery. Considering this information, the aim of this review is to provide researchers in the field with a comprehensive understanding of the current state of BMVs as SDDSs, enabling them to identify critical gaps and formulate new hypotheses to accelerate the progress of the field.

MicroRNAs as Mediators of Adipose Thermogenesis and Potential Therapeutic Targets for Obesity

Obesity is a growing health problem worldwide, associated with an increased risk of multiple chronic diseases. The thermogenic activity of brown adipose tissue (BAT) correlates with leanness in adults. Understanding the mechanisms behind BAT activation and the process of white fat "browning" has important implications for developing new treatments to combat obesity. MicroRNAs (miRNAs) are small transcriptional regulators that control gene expression in various tissues, including adipose tissue. Recent studies show that miRNAs are involved in adipogenesis and adipose tissue thermogenesis. In this review, we discuss recent advances in the role of miRNAs in adipocyte thermogenesis and obesity. The potential for miRNA-based therapies for obesity and recommendations for future research are highlighted, which may help provide new targets for treating obesity and obesity-related diseases.