Transferrin-conjugated SNALPs encapsulating 2'-O-methylated miR-34a for the treatment of multiple myeloma.

Stable nucleic acid lipid vesicles (SNALPs) encapsulating miR-34a to treat multiple myeloma (MM) were developed. Wild type or completely 2'-O-methylated (OMet) MiR-34a was used in this study. Moreover, SNALPs were conjugated with transferrin (Tf) in order to target MM cells overexpressing transferrin receptors (TfRs). The type of miR-34a chemical backbone did not significantly affect the characteristics of SNALPs in terms of mean size, polydispersity index, and zeta potential, while the encapsulation of an OMet miR-34a resulted in a significant increase of miRNA encapsulation into the SNALPs. On the other hand, the chemical conjugation of SNALPs with Tf resulted in a significant decrease of the zeta potential, while size characteristics and miR-34a encapsulation into SNALPs were not significantly affected. In an experimental model of MM, all the animals treated with SNALPs encapsulating miR-34a showed a significant inhibition of the tumor growth. However, the use of SNALPs conjugated with Tf and encapsulating OMet miR-34a resulted in the highest increase of mice survival. These results may represent the proof of concept for the use of SNALPs encapsulating miR-34a for the treatment of MM.

Enhanced antioxidant effect of trans-resveratrol: potential of binary systems with polyethylene glycol and cyclodextrin.

Trans-resveratrol, a polyphenol extracted from Vitis vinifera, has different beneficial effects following its administration on the skin. Here the potential use of binary systems to enhance in vitro and in vivo activity of trans-resveratrol was investigated. Thus the aqueous solubility of trans-resveratrol was investigated in the presence of growing concentrations of polyethylene glycol (PEG) or ß-cyclodextrin (ßCD) as solubilizing excipients. Then, the solid dispersion of trans-resveratrol with PEG or inclusion complexes trans-resveratrol/ßCD were prepared and characterised by different methods. Cytotoxicity and inhibition of reactive oxygen species (ROS) following H2O2 challenge in the presence of trans-resveratrol, alone or associated to the excipients, was evaluated on human keratinocyte HaCaT cell line. Both the trans-resveratrol-containing binary systems induced significant reduction of H2O2-induced ROS production, especially in the case of ßCD that was selected for the following phase of the study. Thus, the effect of a cream containing trans-resveratrol, alone or associated to ßCD, on different skin parameters such as corneometry, colorimetry and elastometry, was evaluated on human volunteers. All patients showed a visible improvement of clinical conditions with a remarkable decrease of aging signs, but this effect was higher of the hemi face treated with the ßCD-containing formulation versus formulation containing trans-resveratrol alone.

MicroRNA 199b-5p delivery through stable nucleic acid lipid particles (SNALPs) in tumorigenic cell lines.

MicroRNA (miR)-199b-5p has been shown to regulate Hes-1, a downstream effector of the canonical Notch and noncanonical SHH pathways, whereby it impairs medulloblastoma (MB) cancer stem cells (CSCs) through a decrease in the CD133+/CD15+ cell population. Here, we have developed stable nucleic acid lipid particles (SNALPs) that encapsulate miR-199b-5p. The efficacy of the miR-199b-5p delivery by these SNALPs is demonstrated by significant impairment of Hes-1 levels and CSC markers in a range of different tumorigenic cell lines: colon (HT-29, CaCo-2, and SW480), breast (MDA-MB231T and MCF-7), prostate (PC-3), glioblastoma (U-87), and MB (Daoy, ONS-76, and UW-228). After treatment with SNALP miR-199b-5p, there is also impairment of cell proliferation and no signs of apoptosis, as measured by caspases 3/7 activity and annexin V fluorescence cell sorter analyses. These data strengthen the importance of such carriers for miRNA delivery, which show no cytotoxic effects and provide optimal uptake into cells. Thus, efficient target downregulation in different tumorigenic cell lines will be the basis for future preclinical studies.

Nanocarriers for topical administration of resveratrol: a comparative study.

The trans-resveratrol (t-res), a non-flavonoid polyphenol extracted from different plants, has recently earned interest for application on the skin for different applications. In this work, the potential of nanocarriers, namely transfersomes and ethanol-containing vesicles, to deliver t-res into/through the skin was investigated. Thus, transfersomes with different surfactants, namely polysorbate 80 (Tw80), sodium cholate (SC) and sodium deossicholate (SDC) and ethanol-containing vesicles with different lipid composition, namely soy phosphatidylcholine (SPC) and cholesterol (chol), encapsulating t-res were prepared and characterized. The nanocarriers had a mean diameter ranging between 83 and 116 nm with a high t-res encapsulation efficiency (≥ 70%). Moreover, cytotoxicity as well as the inhibition of production of reactive oxygen species (ROS) and lipid peroxidation, following incubation of H(2)O(2)-stimulated human keratinocyte (HaCaT) with t-res, as free or encapsulated into the nanocarriers, were investigated. Only blank nanocarriers containing Tw80 or ethanol were cytotoxic and led to increase of ROS, but this effect was not observed when using nanocarriers encapsulating t-res. Finally, permeation studies on porcine skin carried out on Franz diffusion cells, showed that only ethanol-containing vesicles based SPC were able to promote t-res permeation through the skin.

MiR-34a targeting of Notch ligand delta-like 1 impairs CD15+/CD133+ tumor-propagating cells and supports neural differentiation in medulloblastoma.

BACKGROUND: Through negative regulation of gene expression, microRNAs (miRNAs) can function as oncosuppressors in cancers, and can themselves show altered expression in various tumor types. Here, we have investigated medulloblastoma tumors (MBs), which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many of the cell-fate-determining stages. Notch regulates a subset of MB cells that have stem-cell-like properties and can promote tumor growth. On the basis of this evidence, we hypothesized that miRNAs targeting the Notch pathway can regulate these phenomena, and can be used in anti-cancer therapies. METHODOLOGY/PRINCIPAL FINDINGS: In a screening of potential targets within Notch signaling, miR-34a was seen to be a regulator of the Notch pathway through its targeting of Notch ligand Delta-like 1 (Dll1). Down-regulation of Dll1 expression by miR-34a negatively regulates cell proliferation, and induces apoptosis and neural differentiation in MB cells. Using an inducible tetracycline on-off model of miR-34a expression, we show that in Daoy MB cells, Dll1 is the first target that is regulated in MB, as compared to the other targets analyzed here: Cyclin D1, cMyc and CDK4. MiR-34a expression negatively affects CD133(+)/CD15(+) tumor-propagating cells, then we assay through reverse-phase proteomic arrays, Akt and Stat3 signaling hypo-phosphorylation. Adenoviruses carrying the precursor miR-34a induce neurogenesis of tumor spheres derived from a genetic animal model of MB (Patch1(+/-) p53(-/-)), thus providing further evidence that the miR-34a/Dll1 axis controls both autonomous and non autonomous signaling of Notch. In vivo, miR-34a overexpression carried by adenoviruses reduces tumor burden in cerebellum xenografts of athymic mice, thus demonstrating an anti-tumorigenic role of miR-34a in vivo. CONCLUSIONS/SIGNIFICANCE: Despite advances in our understanding of the pathogenesis of MB, one-third of patients with MB remain incurable. Here, we show that stable nucleic-acid-lipid particles carrying mature miR-34a can target Dll1 in vitro and show equal effects to those of adenovirus miR-34a cell infection. Thus, this technology forms the basis for their therapeutic use for the delivery of miR-34a in brain-tumor treatment, with no signs of toxicity described to date in non-human primate trials.