Bacterial outer membrane vesicle nanorobot.

Autonomous nanorobots represent an advanced tool for precision therapy to improve therapeutic efficacy. However, current nanorobotic designs primarily rely on inorganic materials with compromised biocompatibility and limited biological functions. Here, we introduce enzyme-powered bacterial outer membrane vesicle (OMV) nanorobots. The immobilized urease on the OMV membrane catalyzes the decomposition of bioavailable urea, generating effective propulsion for nanorobots. This OMV nanorobot preserves the unique features of OMVs, including intrinsic biocompatibility, immunogenicity, versatile surface bioengineering for desired biofunctionalities, capability of cargo loading and protection. We present OMV-based nanorobots designed for effective tumor therapy by leveraging the membrane properties of OMVs. These involve surface bioengineering of robotic body with cell-penetrating peptide for tumor targeting and penetration, which is further enhanced by active propulsion of nanorobots. Additionally, OMV nanorobots can effectively safeguard the loaded gene silencing tool, small interfering RNA (siRNA), from enzymatic degradation. Through systematic in vitro and in vivo studies using a rodent model, we demonstrate that these OMV nanorobots substantially enhanced siRNA delivery and immune stimulation, resulting in the utmost effectiveness in tumor suppression when juxtaposed with static groups, particularly evident in the orthotopic bladder tumor model. This OMV nanorobot opens an inspiring avenue to design advanced medical robots with expanded versatility and adaptability, broadening their operation scope in practical biomedical domains.

Bacterial outer membrane vesicle-cancer cell hybrid membrane-coated nanoparticles for sonodynamic therapy in the treatment of breast cancer bone metastasis.

Breast cancer bone metastasis is a terminal-stage disease and is typically treated with radiotherapy and chemotherapy, which causes severe side effects and limited effectiveness. To improve this, Sonodynamic therapy may be a more safe and effective approach in the future. Bacterial outer membrane vesicles (OMV) have excellent immune-regulating properties, including modulating macrophage polarization, promoting DC cell maturation, and enhancing anti-tumor effects. Combining OMV with Sonodynamic therapy can result in synergetic anti-tumor effects. Therefore, we constructed multifunctional nanoparticles for treating breast cancer bone metastasis. We fused breast cancer cell membranes and bacterial outer membrane vesicles to form a hybrid membrane (HM) and then encapsulated IR780-loaded PLGA with HM to produce the nanoparticles, IR780@PLGA@HM, which had tumor targeting, immune regulating, and Sonodynamic abilities. Experiments showed that the IR780@PLGA@HM nanoparticles had good biocompatibility, effectively targeted to 4T1 tumors, promoted macrophage type I polarization and DC cells activation, strengthened anti-tumor inflammatory factors expression, and presented the ability to effectively kill tumors both in vitro and in vivo, which showed a promising therapeutic effect on breast cancer bone metastasis. Therefore, the nanoparticles we constructed provided a new strategy for effectively treating breast cancer bone metastasis.

Bioengineering Bacterial Vesicle-Coated Polymeric Nanomedicine for Enhanced Cancer Immunotherapy and Metastasis Prevention.

We herein propose a bioengineering approach where bacterial outer membrane vesicles (OMVs) were coated on drug-loaded polymeric micelles to generate an innovative nanomedicine for effective cancer immunotherapy and metastasis prevention. Whereas OMVs could activate the host immune response for cancer immunotherapy, the loaded drug within polymeric micelles would exert both chemotherapeutic and immunomodulatory roles to sensitize cancer cells to cytotoxic T lymphocytes (CTLs) and to kill cancer cells directly. We demonstrated that the systemic injection of such a bioinspired immunotherapeutic agent would not only provide effective protective immunity against melanoma occurrence but also significantly inhibited tumor growth in vivo and extended the survival rate of melanoma mice. Importantly, the nanomedicine could also effectively inhibit tumor metastasis to the lung. The bioinspired immunomodulatory nanomedicine we have developed repurposes the bacterial-based formulation for cancer immunotherapy, which also defines a useful bioengineering strategy to the improve current cancer immunotherapeutic agents and delivery systems.

Bacterial membrane vesicle functions, laboratory methods, and applications.

Bacterial membrane vesicles (BMVs) are cupped-shaped structures formed by bacteria in response to environmental stress, genetic alteration, antibiotic exposure, and others. Due to the structural similarities shared with the producer organism, they can retain certain characteristics like stimulating immune responses. They are also able to carry molecules for long distances, without changes in the concentration and integrity of the molecule. Bacteria originally secrete membrane vesicles for gene transfer, excretion, cell to cell interaction, pathogenesis, and protection against phages. These functions are unique and have several innovative applications in the pharmaceutical industry that have attracted both scientific and commercial interest.This led to the development of efficient methods to artificially stimulate vesicle production, purification, and manipulation in the lab at nanoscales. Also, for specific applications, engineering methods to impart pathogen antigens against specific diseases or customization as cargo vehicles to deliver payloads to specific cells have been reported. Many applications of BMVs are in cancer drugs, vaccines, and adjuvant development with several candidates in clinical trials showing promising results. Despite this, applications in therapy and commercialization stay timid probably due to some challenges one of which is the poor understanding of biogenesis mechanisms. Nevertheless, so far, BMVs seem to be a reliable and cost-efficient technology with several therapeutic applications. Research toward characterizing more membrane vesicles, genetic engineering, and nanotechnology will enable the scope of applications to widen. This might include solutions to other currently faced medical and healthcare-related challenges.

Emerging Technologies for Low-Cost, Rapid Vaccine Manufacture.

To stop the spread of future epidemics and meet infant vaccination demands in low- and middle-income countries, flexible, rapid and low-cost vaccine development and manufacturing technologies are required. Vaccine development platform technologies that can produce a wide range of vaccines are emerging, including: a) humanized, high-yield yeast recombinant protein vaccines; b) insect cell-baculovirus ADDomer vaccines; c) Generalized Modules for Membrane Antigens (GMMA) vaccines; d) RNA vaccines. Herein, existing and future platforms are assessed in terms of addressing challenges of scale, cost, and responsiveness. To assess the risk and feasibility of the four emerging platforms, the following six metrics are applied: 1) technology readiness; 2) technological complexity; 3) ease of scale-up; 4) flexibility for the manufacturing of a wide range of vaccines; 5) thermostability of the vaccine product at tropical ambient temperatures; and 6) speed of response from threat identification to vaccine deployment. The assessment indicated that technologies in the order of increasing feasibility and decreasing risk are the yeast platform, ADDomer platform, followed by RNA and GMMA platforms. The comparative strengths and weaknesses of each technology are discussed in detail, illustrating the associated development and manufacturing needs and priorities.

Preparation of bacterial outer membrane vesicle coated nanoparticle loaded with drug and evaluation of its nasal immune effect in mice / 上海交通大学学报（医学版）

Objective: To prepare a bacterial outer membrane vesicle (OMV) coated poly (lactic-co-glycolic acid) copolymer (PLGA) nanoparticle loaded with ovalbumin (OVA) and evaluate its intranasal immune effect in mice. Methods: OMV was prepared by ultrafiltration concentration method. OVA loaded PLGA nanoparticle (NP) was prepared by emulsion-solvent evaporation method. OMV coated PLGA nanoparticle (OMV-PLGA NP) loaded with OVA was prepared by extrusion method and characterized. BALB/c mice were intranasally immunized and specific sIgA levels in nasal wash, jejunum and fecal pellet were determined by ELISA. Results: Size of OVA loaded OMV-PLGA NP was (234.4±22.9) nm. The shell-core structure of OVA loaded OMV-PLGA NP was proved by transmission electron microscope. After 14 d of administration, sIgA antibody levels in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group were the highest in all treated groups. Compared with the group treated with OMV and OVA, OVA-specific sIgA antibody level in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was increased 1.6, 2.1 and 1.7 times, respectively. Compared with the group treated with OMV and OVA, OMV-specific sIgA antibody level in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was all increased 1.5 times. Conclusion: This novel nanoparticle drug delivery system can simultaneously delivery OVA and OMV to antigen presenting cells, resulting in stronger mucosal immune response in mice.

Preparation of bacterial outer membrane vesicle coated nanoparticle loaded with drug and evaluation of its nasal immune effect in mice / 上海交通大学学报（医学版）

Objective·To prepare a bacterial outer membrane vesicle (OMV) coated poly (lactic-co-glycolic acid) copolymer (PLGA) nanoparticle loaded with ovalbumin (OVA) and evaluate its intranasal immune effect in mice.Methods· OMV was prepared by ultrafiltration concentration method.OVA loaded PLGA nanoparticle (NP) was prepared by emulsion-solvent evaporation method.OMV coated PLGA nanoparticle (OMV-PLGA NP) loaded with OVA was prepared by extrusion method and characterized.BALB/c mice were intranasally immunized and specific sIgA levels in nasal wash,jejunum and fecal pellet were determined by ELISA.Results· Size of OVA loaded OMV-PLGA NP was (234.4±22.9) nm.The shell-core structure of OVA loaded OMV-PLGA NP was proved by transmission electron microscope.After 14 d of administration,sIgA antibody levels in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group were the highest in all treated groups.Compared with the group treated with OMV and OVA,OVA-specific sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was increased 1.6,2.1 and 1.7 times,respectively.Compared with the group treated with OMV and OVA,OMV-specific sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was all increased 1.5 times.Conclusion· This novel nanoparticle drug delivery system can simultaneously delivery OVA and OMV to antigen presenting cells,resulting in stronger mucosal immune response in mice.