The inherent antibiotic activity of myxobacteria-derived autofluorescent outer membrane vesicles is switched on and off by light stimulation.

Outer membrane vesicles are small, lipid-based vesicles shed from the outer membrane of Gram-negative bacteria. They are becoming increasingly recognised as important factors for resistance gene transfer, bacterial virulence factors and host cell modulation. The presence of pathogenic factors and antimicrobial compounds in bacterial vesicles has been proven in recent years, but it remains unclear, if and how environmental factors, such as light specifically regulate the vesicle composition.

Bacteriomimetic Liposomes Improve Antibiotic Activity of a Novel Energy-Coupling Factor Transporter Inhibitor.

Liposomes have been studied for decades as nanoparticulate drug delivery systems for cytostatics, and more recently, for antibiotics. Such nanoantibiotics show improved antibacterial efficacy compared to the free drug and can be effective despite bacterial recalcitrance. In this work, we present a loading method of bacteriomimetic liposomes for a novel, hydrophobic compound () inhibiting energy-coupling factor transporters (ECF transporters), an underexplored antimicrobial target.

An Outer Membrane Vesicle-Based Permeation Assay (OMPA) for Assessing Bacterial Bioavailability.

When searching for new antibiotics against Gram-negative bacterial infections, a better understanding of the permeability across the cell envelope and tools to discriminate high from low bacterial bioavailability compounds are urgently needed. Inspired by the phospholipid vesicle-based permeation assay (PVPA), which is designed to predict non-facilitated permeation across phospholipid membranes, outer membrane vesicles (OMVs) of Escherichia coli either enriched or deficient of porins are employed to coat filter supports for predicting drug uptake across the complex cell envelope. OMVs and the obtained in vitro model are structurally and functionally characterized using cryo-TEM, SEM, CLSM, SAXS, and light scattering techniques.

Interaction of myxobacteria-derived outer membrane vesicles with biofilms: antiadhesive and antibacterial effects.

Bacterial biofilms are widespread in nature and in medical settings and display a high tolerance to antibiotics and disinfectants. Extracellular vesicles have been increasingly studied to characterise their origins and assess their potential for use as a versatile drug delivery system; however, it remains unclear whether they also have antibiofilm effects. Outer membrane vesicles are lipid vesicles shed by Gram-negative bacteria and, in the case of myxobacteria, carry natural antimicrobial compounds produced by these microorganisms.

Coupling quaternary ammonium surfactants to the surface of liposomes improves both antibacterial efficacy and host cell biocompatibility.

By functionalizing the surface of PEG-liposomes with linkers bearing quaternary ammonium compounds (QACs), we generated novel bacteria disruptors with anti-adhesive properties and reduced cytotoxicity compared to free QACs. Furthermore, QAC-functionalized liposomes are a promising platform for future drug encapsulation. The QAC (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide (MTAB) was attached to maleimide-functionalized liposomes (DSPE-PEG) via thiol linker.

Myxobacteria-Derived Outer Membrane Vesicles: Potential Applicability Against Intracellular Infections.

In 2019, it was estimated that 2.5 million people die from lower tract respiratory infections annually. One of the main causes of these infections is , a bacterium that can invade and survive within mammalian cells.

PLGA nanocapsules improve the delivery of clarithromycin to kill intracellular Staphylococcus aureus and Mycobacterium abscessus.

Drug delivery systems are promising for targeting antibiotics directly to infected tissues. To reach intracellular Staphylococcus aureus and Mycobacterium abscessus, we encapsulated clarithromycin in PLGA nanocapsules, suitable for aerosol delivery by nebulization of an aqueous dispersion. Compared to the same dose of free clarithromycin, nanoencapsulation reduced 1000 times the number of intracellular S.

Biocompatible bacteria-derived vesicles show inherent antimicrobial activity.

Up to 25,000 people die each year from resistant infections in Europe alone, with increasing incidence. It is estimated that a continued rise in bacterial resistance by 2050 would lead up to 10 million annual deaths worldwide, exceeding the incidence of cancer deaths. Although the design of new antibiotics is still one way to tackle the problem, pharmaceutical companies investigate far less into new drugs than 30 years ago.

Biogenic and Biomimetic Carriers as Versatile Transporters To Treat Infections.

Biogenic and biomimetic therapeutics are a relatively new class of systems that are of physiological origin and/or take advantage of natural pathways or aim at mimicking these to improve selective interaction with target tissue. The number of biogenic and bioengineered avenues for drug therapy and diagnostics has multiplied over the past years for many applications, indicating the high expectations associated with this biological route. Nevertheless, the use of "bio"-related approaches for treating or diagnosing infectious diseases is still rare.