Towards analyzing the potential of exosomes to deliver microRNA therapeutics.

Exosome selectivity mechanisms underlying exosome-target cell interactions and the specific traits affecting their capability to communicate still remain unclear. Moreover, the capacity of exosomes to efficiently deliver their molecular cargos intracellularly needs precise investigation towards establishing functional exosome-based delivery platforms exploitable in the clinical practice. The current study focuses on: (a) exosome production from normal MRC-5 and Vero cells growing in culture, (b) physicochemical characterization by dynamic light scattering (DLS) and cryo-transmission electron microscopy; (c) cellular uptake studies of rhodamine-labeled exosomes in normal and cancer cells, providing to exosomes either "autologous" or "heterologous" cellular delivery environments; and (d) loading exogenous Alexa Fluor 488-labeled siRNA into exosomes for the assessment of their delivering capacity by immunofluorescence in a panel of recipient cells. The data obtained thus far indicate that MRC-5 and Vero exosomes, indeed exhibit an interesting delivering profile, as promising "bio-shuttles," being pharmacologically exploitable in the context of theranostic applications.

Electrosprayed mesoporous particles for improved aqueous solubility of a poorly water soluble anticancer agent: in vitro and ex vivo evaluation.

Encapsulation of poorly water-soluble drugs into mesoporous materials (e.g. silica) has evolved as a favorable strategy to improve drug solubility and bioavailability. Several techniques (e.g. spray drying, solvent evaporation, microwave irradiation) have been utilized for the encapsulation of active pharmaceutical ingredients (APIs) into inorganic porous matrices. In the present work, a novel chalcone (KAZ3) with anticancer properties was successfully synthesized by Claisen-Schmidt condensation. KAZ3 was loaded into mesoporous (SBA-15 and MCM-41) and non-porous (fumed silica, FS) materials via two techniques; electrohydrodynamic atomization (EHDA) and solvent impregnation. The effect of both loading methods on the physicochemical properties of the particles (e.g. size, charge, entrapment efficiency, crystallinity, dissolution and permeability) was investigated. Results indicated that EHDA technique can load the active in a complete amorphous form within the pores of the silica particles. In contrast, reduced crystallinity (~79%) was obtained for the solvent impregnated formulations. EHDA engineered formulations significantly improved drug dissolution up to 30-fold, compared to the crystalline drug. Ex vivo studies showed EHDA formulations to exhibit higher permeability across rat intestine than their solvent impregnated counterparts. Cytocompatibility studies on Caco-2 cells demonstrated moderate toxicity at high concentrations of the anticancer agent. The findings of the present study clearly show the immense potential of EHDA as a loading technique for mesoporous materials to produce poorly water-soluble API carriers of high payload at ambient conditions. Furthermore, the scale up potential in EHDA technologies indicate a viable route to enhance drug encapsulation and dissolution rate of loaded porous inorganic materials.

Metabolomics assisted fingerprint of Hypericum perforatum chemotypes and assessment of their cytotoxic activity.

Hypericum perforatum is known as an important medicinal plant, used for the treatment of several diseases, while its pharmacological properties are attributed to the presence of a wide range of secondary metabolites. Due to the great chemotypic variability of Hypericum species in the nature, and the demand for standardized herbal products, a detailed phytochemical investigation was carried out on different parts (herba, leaf, flowers) from wild collected and cultivated populations, using advanced chromatographic tools. Liquid Chromatographic analysis (LC-MS/MS MRM) revealed significant variability in the secondary metabolites content of the examined methanolic extracts. The most common derivatives belong to 9 groups i.e. benzoic acids, phenylpropanoids, coumarins, flavones, flavonols, flavan-3-ols, anthocyanins, phloroglucinols and naphtodianthrones. The main polyphenolic compounds were catechin, epicatechin, quercetin, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, neochlorogenic acid, proanthocyanidins (A and B series) and cyanidin-3-O-glucoside. In addition, the content of the characteristic compounds hypericin and hyperforin in herba crude extracts ranged between 0.5 and 1.7 mg/g and 0.6-3.3 mg/g respectively. The cytotoxic activity of the crude extracts was assessed at concentrations ranged between 0.01 and 100 µg/mL, on Caco-2 intestinal cancer cell cultures, and a cytotoxic behavior was shown only at the highest concentration of 100 µg/mL.