Extracellular vesicles (EVs) are emerging as novel theranostic tools. Limitations related to clinical uses are leading to a new research area on design and manufacture of artificial EVs. Several strategies have been reported in order to produce artificial EVs, but there has not yet been a clear criterion by which to differentiate these novel biomaterials. In this paper, we suggest for the first time a systematic classification of the terms used to build up the artificial EV landscape, based on the preparation method. This could be useful to guide the derivation to clinical trial routes and to clarify the literature. According to our classification, we have reviewed the main strategies reported to date for their preparation, including key points such as: cargo loading, surface targeting strategies, purification steps, generation of membrane fragments for the construction of biomimetic materials, preparation of synthetic membranes inspired in EV composition and subsequent surface decoration.

Bionanotechnology routes have been recently developed to produce fully artificial exosomes: biomimetic particles designed to overcome certain limitations in extracellular vesicle (EV) biology and applications. These particles could soon become true therapeutic biomaterials. Here, we outline their current preparation techniques, their explored and future possibilities, and their present limits.

The translation of continuous-flow microreactor technology to the industrial environment has been limited by cost and complexity of the fabrication procedures and the requirement for specialised infrastructure. In the present study, we have developed a significantly more cost-effective and easy-to-perform fabrication method for the generation of optically transparent, continuous-flow reactors. The method combines 3D printing of master moulds with sealing of the PDMS channels' replica using a pressure-sensitive adhesive tape. Morphological characterisation of the 3D printed moulds was performed and reactors were fabricated with an approximately square-shaped cross-section of 1 mm. Notably, they were tested for operation over a wide range of volumetric flow rates, up to 20 ml/min. Moreover, the fabrication time (i.e., from design to the finished product) was <1 day, at an average material cost of ∼£5. The flow reactors have been applied to the production of both inorganic nanoparticles (silver nanospheres) and organic vesicular systems (liposomes), and their performance compared with reactors produced using more laborious fabrication methods. Numerical simulations were performed to characterise the transport of fluids and chemical species within the devices. The developed fabrication method is suitable for scaled-up fabrication of continuous-flow reactors, with potential for application in biotechnology and nanomedicine.

No abstract

The aim of this work was to prepare size-tuned

In this study, nanovesicles such as transfersomes, niosomes, and liposomes prepared by an ethanol injection method (EIM) (EIM) and formulated with soybean lecithin, Tween 80, Span 60, and cholesterol, are used to improve the bioavailability of taxifolin, a natural antioxidant with beneficial properties for health and food preservation. Morphology, stability, and the in-vitro release of the optimal formulations are fully examined. The obtained results indicate that taxifolin-loaded nanovesicles present sizes ranging between 98 and 215 nm along with a narrow size distribution (polydispersity index less than 0.250). The zeta potential of nanovesicles is negative and in the range of −20.40 to −32.20 mV. The optimal formulations with the maximum encapsulation efficiency (72-75%) are the transfersomes formulated with lecithin and Tween 80 in the presence and absence of cholesterol. Additionally, in vitro release behavior of nanovesicles shows low taxifolin released (3.68-10.13%) at intestinal conditions, whereas more than 90% of taxifolin is released in gastrointestinal conditions. The compatibility between taxifolin and nanovesicles components is confirmed by FTIR. Transmission electron microscopy demonstrates spherical shaped particles around 200 nm. Backscattering profiles variations show the potential application of taxifolin nanovesicles for producing fortified apple juice with excellent physical stability. Practical Applications: Taxifolin is a flavanonol, which fulfills a particular task in preserving stable functions of the circulatory system owing to its special antioxidant ability and biological activity. Nevertheless, its low bioavailability is a salient drawback for biomedical and food applications. Thus, the current study is conducted to encapsulate taxifolin in nanovesicles (such as liposome, niosome, transfersome) by EIM to improve its bioavailability. Nanocarriers with relatively decent physical stability and high encapsulation efficiency can be brought about through Tween 80, soybean lecithin, and in the presence and absence of cholesterol as stabilizer which ensures the successful delivery of taxifolin to food formats such as beverages.

The new roles of vesicular systems in advanced biomedical, analytical and food science applications demand novel preparation processes designed to reach the new standards. Particle size and monodispersity have become essential properties to control. In this work, key parameters, involved in a microfluidic reactor with hydrodynamic flow focusing, were investigated in order to quantify their effects on niosomes morphology. Particular attention was given to temperature, which is both a requirement to handle non-ionic surfactants with phase transition temperature above RT, and a tailoring variable for size and monodispersity control. With this aim, niosomes with two different sorbitan esters and cholesterol as stabilizer were formulated. High resolution and conventional 3D-printing technologies were employed for the fabrication of microfluidic reactor and thermostatic systems, since this additive technology has been essential for microfluidics development in terms of cost-effective and rapid prototyping. A customised device to control temperature and facilitate visualization of the process was developed, which can be easily coupled with commercial inverted microscopes. The results demonstrated the capability of microfluidic production of niosomes within the full range of non-ionic surfactants and membrane stabilizers.

Copper nanoparticles (CuNPs) stabilized by quaternary ammonium salts are well known as antimicrobial agents. The aim of this work was to study the feasibility of the inclusion of CuNPs in nanovesicular systems. Liposomes are nanovesicles (NVs) made with phospholipids and are traditionally used as delivery vehicles because phospholipids favor cellular uptake. Their capacity for hydrophilic/hydrophobic balance and carrier capacity could be advantageous to prepare novel hybrid nanostructures based on metal NPs (Me-NPs). In this work, NVs were loaded with CuNPs, which have been reported to have a biofilm inhibition effect. These hybrid materials could improve the effect of conventional antibacterial agents. CuNPs were electro-synthesized by the sacrificial anode electrolysis technique in organic media and characterized in terms of morphology through transmission electron microscopy (TEM). The NVs were prepared by the thin film hydration method in aqueous media, using phosphatidylcholine (PC) and cholesterol as a membrane stabilizer. The nanohybrid systems were purified to remove non-encapsulated NPs. The size distribution, morphology and stability of the NV systems were studied. Different quaternary ammonium salts in vesicular systems made of PC were tested as stabilizing surfactants for the synthesis and inclusion of CuNPs. The entrapment of charged metal NPs was demonstrated. NPs attached preferably to the membrane, probably due to the attraction of their hydrophobic shell to the phospholipid bilayers. The high affinity between benzyl-dimethyl-hexadecyl-ammonium chloride (BDHAC) and PC allowed us to obtain stable hybrid NVs c.a. 700 nm in diameter. The stability of liposomes increased with NP loading, suggesting a charge-stabilization effect in a novel antibiofilm nanohybrid material.